[From the U.S. Government Printing Office, www.gpo.gov]









                                               Department of Natural Resources
                                           MARYLAND GEOLOGICAL SURVEY
                                                   Emery T. Cleaves, Director



                                          COASTAL AND ESTUARINE GEOLOGY
                                                 OPEN FILE REPORT NO. 15


               Geochemistry and geophysical framework of the shallow
                0 V%
                  sediments of Assawoman Bay and Isle of Wight Bay in
                                                         Maryland

                                                                by
                                Darlene V. Wells, Robert D. Conkwright, and June Park



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                                                         0

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                                                                 1632






                                                            Submitted to
                                                     U.S.Department of the Interior
                                                     Minerals Management Service
                                                     Continental Margins Program
                                                                and
                                                     Bureau of Economic Geology
                                                  The University of Texas at Austin


                                                           in fulfillment of
                                                     Contract #14-35-0001-30534


                  QE
                  121
                  W45                                           1994
                  1994











                                              Department of Natural Resources
                                         MARYLAND GEOLOGICAL SURVEY
                                                 Emery T. Cleaves, Director



                                        COASTAL AND ESTUARINE GEOLOGY
                                               OPEN FILE REPORT NO. 15


              Geochemistry and geophysical framework of the shallow
                sediments of Assawoman Bay and Isle of Wight Bay in
                                                       Maryland

                                                               by
                              Darlene V. Wells, Robert D. Conkwright, and June Park



                                                         0

                                                                   4@



                                                               163






                                                          Submitted to
                                                   U.S.Department of the Interior
                                                   Minerals Management Service
                                                   Continental Margins Program
                                                              and
                                                   Bureau of Economic Geology
                                                The University of Texas at Austin


                                                        in fulfillment of
                                                   Contract #14-35-0001-30534




                                                              1994































                                    COMMISSION
                                      OF THE
                            MARYLAND GEOLOGICAL SURVEY


                            M. GORDON WOLMAN, CHAIRMAN
                                   JOHN E. CAREY
                                F. PIERCE LINAWEAVER
                                  THOMAS 0. NUTTLE
                                  ROBERT W. RIDKY

























                                         ii









                                                CONTENTS


                                                                                               Page
          Abstract     ....................................................                        I


          Introduction     .................................................                       3
                 Objectives   ...............................................                      3
                 Acknowledgements       ........................................                   4
                 Previous Studies    ..........................................                    4

          Study Area     ...................................................                       5
                 Geologic Setting    ..........................................                    5
                 Physical Characteristics  ................................              I ....    8

          Summary and Conclusions       ................       ............     I  ..........     10

          Results and Discussion     ...........................................                  12
                 Seismic Profiles  ....................................               I ......    12
                 Sediment Texture    ..........................................                   16
                 Water Content    ............................................                    18
                 Geochemistry     ............................................                    19
                         Nitrogen Content   .....................................                 19
                         Carbon Content    ......................................                 20
                         Sulfur Content .......................................                   21
                         Metals  ..............................................                   22
                               Enrichment Factors   ......     ........................           23
                               Variation from Historical Norms     .....................          26


          Methods      ....................................................                       28
                 Seismic Profiling   ..........................................                   28
                 Coring Techniques     .........................................                  28
                 Laboratory Analyses    .......................................                   29
                         Xeroradiography and Initial Core Processing     .................        29
                         Textural Analyses    ....................................                29
                         Chemical Analyses    ....................................                31
                               Nitrogen, Carbon, and Sulfur Analyses     .................        31
                               Monosulfide Analyses     .............................             32
                               Metal Analyses     .................................               33


          References Cited     ..............................................                     35









                                                     CONTENTS (continued)
                                                                                                               Page
                   Appendix I
                           Location data for coring sites and selected seismic surveys        .............       42

                   Appendix II
                           Lithologic logs and xeroradiographs for sediment cores collected in Isle of
                           Wight and Assawoman Bays           ..................................                  45

                   Appendix III
                           Textural and geochernical data for core sediment samples          ..............       69

                   Appendix IV
                           Microwave digestion technique      ................................                  125




                                                              FIGURES


                   Figure 1.          A) Generalized geologic map of central Delmarva
                                      Peninsula    ..........................................                       6
                                      B) Cross-section (with key) showing stratigraphic
                                      relationship of formations (from Owens and Denny,
                                      1979)    .............................................                        7

                   Figure 2.          A) West end of record for seismic line 3 which crosses
                                      the widest part of, Isle of Wight Bay. B) Interpreted
                                      section    showing     prominent      reflector    defining
                                      paleochannel and pre-transgression surface        .................         13

                   Figure 3.          A) Record for seismic line 8, crossing north
                                      Assawoman Bay. B) Interpreted section featuring cross-
                                      section of a dredged hole adjacent to Montego Bay
                                      Trailer Park located on bay side of North Ocean City,
                                      Maryland     .........................................                      14

                   Figure    4.       Contour of surface defined by the prominent reflector
                                      seen in seismic profiles     ...............................                15

                   Figure    5.       Map of the track lines for seismic profile surveys with
                                      locations of core and surficial sediment stations   . .............         30


                                                                   iv









                                                    TABLES
                                                                                                   Page
           Table     1.      Morphological parameters of Isle of Wight and
                             Assawoman Bays       ....................................                8,

           Table II.         Correlation matrix for nitrogen, carbon, sulfur contents
                             and sediment textural data based on all core samples
                             except station 14   ....................................                18

           Table 111.        Correlation matrix for trace metal concentrations and
                             sediment textural data based on all core samples except
                             station 14   .........................................                  22


           Table IV.         Comparisons of average enrichment factors in various
                             East and Gulf Coast estuaries (modified from Sinex
                             and Helz, 1981)     ....................................                25

           Table     V.      Least squares coefficients for trace metal data    ...............      26

           Table VI.         Results of nitrogen, carbon, and sulfur analyses of
                             NIST-SRM #1646 (Estuarine Sediment) material
                             compared to the certified or known values     ..................        32

           Table VII.        Results of the metal analyses of reference materials
                             compared to the certified values    .........................           34

           Table VIII.       Coordinates (latitude and longitude) of time fixes for
                             seismic surveys conducted in May, 1992       ...................        43

           Table IX          Geographical coordinates and general information for
                             sampling stations   ....................................                44

           Table     X.      Textural data for sediment samples taken from cores      ..........     70

           Table XI.         Chemical data for sediment samples      ......................          73

           Table XII.        Enrichment factors for metals analyzed          in core
                             sediments   ........................................                   104







                                                         v








                                                      TABLES (continued)
                                                                                                            Page
                   Table XIII.       Mean and sigma levels of variation values calculated
                                     from me  tal concentrations of sediments below 30 cm
                                     in the sediment column     ..............................               120


                   Table XIV.        Variation values for metal concentrations relative to
                                     background levels    ..................................                 121





                                                          EQUATIONS


                   Equation 1.       Calculation of the enrichment factor for a particular
                                     metal in sediment samples      .............................             23

                   Equation 2.       Calculation of background metal concentration        using
                                     grain size composition of the sediment      ....................         26

                   Equation 3.       Determination of variation of measured               metal
                                     concentrations     relative   to    background      metal
                                     concentration    ......................................                  27


                   Equation 4.       Determination of water content as percent, wet
                                     weight    ...........................................                    29



















                                                                 vi








                   Geochemistry and geophysical framework of the shallow sediments
                          of Assawoman Bay and Isle of Wight Bay in Maryland

                                                       by
                           Darlene V. Wells, Robert D. Conkwright, and June Park



                                                  ABSTRACT


                  For the 8th year of the Mineral Management Service's Continental Margins
           Program, the Maryland Geological Survey conducted a sedimentological and geochernical
           study of the sediments of Isle of Wight and Assawoman Bays. The objectives of the study
           were to delineate the shallow stratigraphic sequence of the coastal bays, relating the
           stratigraphy to late Quaternary sea level fluctuations, and to document the geochernical
           character of the shallow sediments, providing preliminary base-line data for comparison
           for future studies.


                  Thirty-three kilometers of 7 kHz seismic profile surveys and eleven sediment cores
           were collected. Surficial sediments grab samples were collected at three other stations.
           The cores were X-rayed, described and sampled at various intervals. A total of 96
           sediment samples were analyzed for texture (SAND, SILT, CLAY contents), water
           content, total nitrogen, carbon, and sulfur concentrations, and six metals: Cr, Cu, Fe, Mn,
           Ni and Zn.


                  Seismic records feature several shallow paleochannels defined by a very strong
           reflector.  Depths to the reflector were mapped, allowing the structure of a pre-
           transgression surface beneath the bays to be contoured. The surface reveals a simple
           paleodrainage system which is traceable to the present tributaries. Maximum depths of
           the paleochannels are approximately 8 meters below MSL. Thalweg depths, particularly
           for the St. Martin paleochannel, are much shallower than previously projected based on
           well log and bridge boring data.

                  The coastal bay sediments are predominately SILTY. SILT contents averaged 44%
           for all samples. Averages for SAND and CLAY contents are 31% and 25%, respectively.
           SAND contents generally are higher for those samples collected along the eastern margin
           of the bays. CLAY becomes an important component in cores collected in the tributaries.

                  Concentrations for nitrogen, carbon and sulfur for most of the sediments are within
           ranges expected for marine sediments and are comparable with those found in the
           Chesapeake Bay and other Atlantic coast estuaries. Nitrogen contents range from 0 to
           1.39%, averaging 0.22%; carbon contents range from 0.02 to 30%, averaging 2.8%; and


                                                        I








                  sulfur contents range from 0 to 5.28%, averaging 1.05%. Nitrogen, carbon and sulfur
                  contents are strongly related to the texture of the coastalbay sediments, with higher
                  values associated with finer-grained sediments.

                         Metal concentrations are within the ranges of other coastal bays not subject to
                  heavy industry. The behavior of the metals were determined by two methods. The first
                  method utilized enrichment factors referenced to average continental crust (Taylor, 1964).
                  Enrichment factor values for Cu, Mn and Ni are less than one for most of the sediments
                  suggesting that the reference material used may not represent the coastal bay sediments.
                  Nevertheless, enrichment factors indicate that the upper 20 to 30 cm of sediment column
                  are enriched with Cr, Cu, Ni and Zn compared to sediments deeper than 30 cm. The
                  metal concentrations in the deeper sediments are interpreted to represent historical or
                  background levels.

                         The second technique employed to assess metal concentrations in the sediments
                  correlated metal content with the grain size composition. Sediment deeper than 30 cm
                  were used to obtain the relationship between texture and metal contents to determine
                  background metal concentrations. Background levels were calculated for all samples and
                  compared to measured levels, obtaining variation factors. Variation factors showed the
                  same trends in the behavior of Cu and Zn as did the enrichment factors.































                                                               2










                                               INTRODUCTION


                  During the past seven years of the Mineral Management Service-Association of
           American State Geologist Continental Margins Program, the Maryland Geological Survey
           has mapped the surficial sediments and defined the shallow geological framework of the
           inner continental shelf of Maryland (Kerhin and Williams, 1987; Toscano et aL, 1989).
           These continental shelf studies consisted of sedimentological, paleontological,
           stratigraphical and geophysical investigations. Stratigraphic horizons, identified in seismic
           records, were correlated to onshore stratigraphy based on data from existing well logs.
           Paleochannels were also mapped, reconstructing the early Holocene inner-shelf
           paleodrainage system.

                  The area of focus for the previous studies have been limited to the inner continental
           shelf of Maryland, and did not include the adjacent coastal bay systems. These coastal
           bays consist of four bays: Assawoman Bay, Isle of Wight Bay, Sinepuxent Bay and
           Chincoteague Bay. These coastal bays mark the leading edge boundary of the present
           transgression and overlie sedimentary sequences that link the onshore and offshore
           stratigraphy. Therefore, studies of the geologic framework of these bays would contribute
           to the understanding of the relationship between offshore and onshore stratigraphy and the
           history of the holocene transgression. However, there have been few studies investigating
           the shallow stratigraphy or geologic history of Maryland's coastal bays,

                  The coastal bays are considered very valuable resources not only from a geological
           viewpoint, but from an environmental perspective.           During the last two decades,
           development pressures along the shoreline around the bays have caused concern about the
           "health" of the bays. Yet, there is a paucity of environmental data available to adequately
           assess and monitor the bays.        Little is understood about the hydrodynamics and
           sedimentation processes. An understanding of the hydrodynamics of the bays is critical
           in dealing with dredging and disposal of polluted sediments. Because the bays are very
           shallow, bottom sediments are often resuspended, mixing with the overlying water
           column. Therefore, the bottom sediments play an important role in bay water quality.
           Sedimentological studies are important to the understanding of the relationship between
           bottom sediments and bay hydrodynamics as well as to the general health of the bays.




           OBJECTIVES


                  The Maryland Geological Survey initiated this study to define the shallow
           geological framework and near surface geochemical character of the sediments of
           Maryland's two northern-most coastal bays: Assawoman Bay and Isle of Wight Bay. The


                                                         3








                   objectives of this study were:
                           1) To delineate the shallow stratigraphic sequence beneath the coastal bays and
                              relate the stratigraphy to late Quaternary sea level fluctuations;
                           2) To map the geochernical character of the near surface sediments of the bays,
                              providing preliminary base-line data for future studies of these back-bay areas.

                           Presented in this report are the results of the first year study. Results include
                   geophysical data from shallow seismic surveys, and textural and chemical data from
                   analyses of sediments taken from a series of shallow cores.





                   ACKNOWLEDGEMENTS


                           This study was supported by the U.S. Mineral Management Service and the
                   Association of American State Geologist Continental Margin Program, and the Maryland
                   Department of Natural Resources. David Blough, and Margarite Carruthers assisted in
                   the collection and initial processing of the sediment cores, and with the textural and
                   chemical analyses of the samples. The authors extend their appreciation to the Fisheries
                   Division of the Department of Natural Resources Tidewater Administration for the use of
                   their boat and equipment. The authors express special thanks to Al Wesche for his
                   assistance in the collection of the cores and seismic data. His intimate knowledge of the
                   back bays proved to be invaluable. The authors extend their appreciation to Dr. James
                   Hill for his assistance with the interpretation of the metals and carbon, sulfur and nitrogen
                   data and for his review of the manuscript. The authors also thank Randall Kerhin and Dr.
                   Emery Cleaves for their suggestions and comments.





                   PREVIOUS STUDIES


                           The general stratigraphy of the eastern Delmarva Peninsula has been described by
                   Owens and Denny (1976), Mixon (1985), and Sheridan et aL (1974) (Delaware).
                   Chrzastowski (1986) investigated the stratigraphy and geologic history of Rehoboth and
                   Indian River Bays in Delaware. Halsey (1978) described the shallow stratigraphy
                   beneath Maryland's coastal bays including Isle of Wight and Assawoman Bays.

                           More recent work relating onshore stratigraphy to offshore stratigraphy include
                   Kerhin and William (1987), Toscano (1992), Toscano el aL (1989), and Toscano and


                                                                 4








           York (1992). Toscano el aL (1989) also mapped a network of paleochannels on
           Maryland's inner continental shelf. These paleochannels are interpreted to be part of the
           ancestral St. Martin River System. Offshore seismic records show the main stem of the
           channel cutting into the top of the Beaverdam sand (Tertiary). Based on thalweg depths,
           widths and orientations, the main channel stem follows a depression in the top of the
           Beaverdam Formation. This depression extends under Fenwick Island and Isle of Wight
           Bay.

                  Very few studies have investigated the geochemical characteristics of sediments in
           Maryland's coastal bays. Most previous environmental studies focused on biological
           aspects (UM and CESI, 1993). Some studies looked at the chemistry of the water column
           in the bays. Early studies primarily focused on water quality monitoring in the bays
           (Sieling 1958, 1959, 1960; Cerco el aL, 1978; and Allison 1975). Water column studies
           conducted by Allison (1975) measured pH, salinity, water temperature, dissolved oxygen
           (D.O.), nutrients, chlorophyll-a, total iron, heavy metal and pesticide concentrations,
           turbidity, and fecal coliform bacteria. At twelve (12) sites within Isle of Wight and
           Assawoman Bays, Allison analyzed bottom sediments for six metals: Cu, Cr, Pb, Zn, Cd,
           and Hg. Allison concluded that the metals concentrations in the sediments were not
           s gni icantly high.




                                                  STUDY AREA


           GEOLOGIC SETTING


                  The study area is located on the Atlantic coast of the Delmarva Peninsula (Figure
           la). Isle of Wight and Assawoman Bays are the two northern-most coastal bays in
           Maryland. Fenwick Island, part of the barrier Island/southern spit unit of the Delmarva
           coastal compartment (Fisher, 1967), separates the coastal bays from the Atlantic Ocean.
           The bays are underlain by unconsolidated Coastal Plain sediments, the upper-most 60 m
           of which are Cenozoic in age. Sediments of the Sinepuxent Formation are exposed           along
           much of Maryland's coastal area from Bethany Beach, Delaware, southward to the
           Mary land-V irgin la border and directly underlie the study area (Figure I b). The Sinepuxent
           Formation was described by Owens and Denny (1979) based on information from drill
           holes along Sinepuxent Neck, the designated type locality for the Formation. The
           Sinepuxent Formation is composed of dark colored, poorly sorted, silty fine to medium
           sand with thin beds- of peaty sand and black clay. Heavy minerals are abundant and
           consist of both amphlbole and pyroxene minerals. All of the major clay 'mineral groups:
           kaolinite, montmorillonite, illite and chlorite, are represented. The sand consists of quartz,



                                                          5











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                                  Figure 1.                A) Generalized geologic map of central Delmarva Peninsula (from Owens
                                  and Denny, 1979). See Figure Ib for pattern key.

                                                                                                                 6
















                                 N
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                                   Delaware

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                                                                                                                              EXPLANATION


                                                                                          MARINE-MARGINAL MARINE                    ESTUARINE-FLUVIA71LE


                                                                                          ..........
                                                                                          ..........
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                                                                                                       Formation
                                                                                          ..........
                                                                                          ..........
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                                                                                                                                                    Formation

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                                                                                                       Chrisapealut Group, undivided
                                                                                                         St Mary's Formation
                                                                                                         Choptank Famiation
                                                                                                         Caknat Formation



                          Figure 1.                     B) Cross-section showing stratigraphic relationship of formations shown in
                          Figure la (from Owens and Denny, 1979), with pattern key.


                                                                                                                          7








                  feldspar and abundance of mica (muscovite, biotite, and chlorite). The preponderance of
                  mica make the Sinepuxent Formation lithologically distinct from underlying older units
                  (Owens and Denny, 1979).

                         The Sinepuxent Formation is interpreted to be a marginal marine deposit. The
                  Sinepuxent Formation has been correlated to the offshore Q2 deposits which were
                  determined to be of oxygen-isotope Stage 5 age (between 80 to 120 ka) based on amino-
                  acid racemization (Toscano, 1992; Toscano et aL, 1989; Toscano and York, 1992).

                         Within the study area, the Sinepuxent is underlain by the Beaverdam Sand
                  Formation which is Pliocene in age (Figure lb). The western edge of the Sinepuxent
                  formation lies against the Ironshire Formation which consists of pale yellow to white sand
                  and gravelly sand. Although the Ironshire Formation sits unconformably on top of the
                  Beaverdam, at no point does it underlie the Sinepuxent Formation (Owens and Denny,
                  1979).




                  PHYSICAL CHARACTERISTICS


                         Assawoman Bay and Isle of Wight Bay are microtidal (<2 m tidal range) coastal
                  lagoons and are contiguous with each other. For this discussion, the boundary between
                  Assawoman Bay and Isle of Wight Bay is the Rt. 90 bridge which spans Fenwick Island
                  (Ocean City at 60th Street) and Isle of Wight. Table I lists the basic morphometric data
                  for both bays.


                    Table 1. Morphometric data for Isle of Wight and Assawoman Bays; area data
                    compiled from Bartberger and Biggs (1970) and UM and CESI (1993).

                                               Assawoman Bay        Isle of Wight Bay    Two Bay System
                         Surface area              20.0 kM2             33.4 kM2             5 3.4 kM2
                       Maximum length               7.9 km               6.7 km               14.5 km

                       Maximum width                3.3 km               4.3 km
                         Drainage area             18.4 kM2             152.7 kin2           171.1 km





                                                               8







                  Assawoman Bay, the northem-most bay, has a water surface area of 20.0 kM2
           (4952 acres) (UM and CESI, 1993) and is elongated in north-south direction. The length
           of Assawoman Bay, measured from the mouth of Roy Creek to Rt. 90 bridge, is 7.9 km.
           Maximum width of Assawoman Bay is 3.3 km. Isle of Wight Bay has a surface area of
           33.4 kM2  (8257 acres) (UM and CESI, 1993). The length of this bay, from Rt. 90 Bridge
           to west end of north jetty at the inlet, is 6.7 km.     Maximum width is 4.3 krn, at the
           mouth of St. Martin River.


                  The two bays are connected to the Atlantic Ocean through a single outlet, Ocean
           City Inlet, located at the extreme south end of Isle of Wight Bay.        Ocean City Inlet
           formed during a hurricane in 1933 and was immediately stabilized by jetties to keep it
           opened.

                . Historically, several other inlets have been documented along Fenwick Island
           (Truitt, 1968). These inlets also formed during storms as did the Ocean City inlet, but
           were eventually filled in as a result of natural processes. During the March, 1962, storm,
           also known as the Ash Wednesday Storm, Fenwick Island was breached at approximately
           71st street. A channel approximately 50 ft wide was cut through to the bay (U.S. Army
           Corps of Engineers, 1962). The Army Corps of Engineers immediately filled in the inlet
           with sand dredged from Assawoman Bay.

                  Several streams are tributaries to the two bays. Roy Creek and Greys Creek drain
           into Assawoman Bay. St.'Martin River, Manklin Creek and Tumille Creek drain into
           Isle of Wight Bay. St. Martin River is the major tributary, accounting for 62% of the
           total drainage area for the bays (Bartberger and Biggs, 1970; UM and CESI, 1993).
           Drainage area for Isle of Wight Bay is about 4.5 times the area of the bay itself (Table
           1). On the other hand, the surface area of Assawoman Bay is slightly larger (1.1 times)
           than its drainage area. In all, the drainage area for both bays is about 3 times as large as
           their open water areas. For comparison, the watershed basin for the Chesapeake Bay is
           28 times its open water area. As a result of the relatively small drainage area combined
           with flat topography, fresh water input into the two coastal bays is small. The limited
           fresh water input and restricted access to open ocean contribute to poor flushing of the
           bays (Bartberger and Biggs, 1970: UM and CESI, 1993).

                  The bays are very shallow, the average depth less than 2 m. Generally, areas with
           greater depths (i.e. > 3 m) are a result of dredging. Some of the deepest areas are within
           the Federal Navigation Channel that is maintained at -10 m. These deep areas are located
           in the southern end of Isle of Wight Bay. Other artificially deep areas include numerous
           dredge holes in Assawoman Bay and along the east side of Isle of Wight Bay. The
           material dredged from these holes were used to fill in low-lying areas on Fenwick Island
           for development, or used as beach fill to replenish the beach in Ocean City after the


                                                        9








                  March 1962 storm. These holes vary in depth from 4.9 to 9.8 m. Another artificially
                  deep area is along a canal known as "The Ditch", the depths of which average 4.5 m.
                  This canal connects Assawoman Bay to Little Assawoman Bay (in Delaware).

                          Circulation patterns and tidal ranges in the two bays are dependent on proximity
                  to the inlet and wind conditions. Near the inlet, currents are primarily an effect of tidal
                  cycles. Currents over 200 cm/sec are common near the inlet and within the Federal
                  Navigation channel. Tidal amplitudes, based on data from NOS tide stations located in
                  southern Isle of Wight Bay, range from 0.78 to 0.55 m. Tidal influence diminishes
                  rapidly with increasing distance from the inlet. Along the western and northern margins
                  of the bays, wind conditions have a greater effect on water levels and current velocities.

                          Casey and Wesche (1981) measured tidal amplitudes and current velocities at
                  several locations in Isle of Wight and Assawoman Bays. Nominal tidal amplitudes ranged
                  from 0.25 m on a spring tide to 0. 16 in during a neap tide at the northern most station,
                  located at Drum Pt. north of Rt. 90 Bridge. Peak ebb and flood velocities were measured
                  between 14 cm/sec and 26 cm/sec at this station. The canal allows some water exchange
                  between Assawoman Bay and Little Assawoman Bay in Delaware. Tidar amplitudes in
                  the canal range from 0.6 to 0.9 m (Allison, 1975).

                          Salinity in the two bays decreases slightly with increasing distance from Ocean
                  City Inlet. Maximum salinity measured during the summer (Casey and Wesche, 1981)
                  ranged from 30 ppt near the inlet to 26 ppt in Assawoman Bay just north of the Rt. 90
                  bridge. Salinity tends to be higher in the summer due to limited freshwater input and
                  high evaporation.

                          Bordering the bays are wetlands and marshes, found mainly along the western
                  margin. Much of the bay side of Fenwick has been developed, at the expense of wetlands
                  (Dolan el aL, 1980). Large areas have been filled in and built up, and much of natural
                  shoreline has been armored by bulkheads or rip-rap.




                                             SUMMARY AND CONCLUSIONS

                          Based on seismic data, a pre-transgressive surface has been mapped, revealing
                  paleodrainage network traceable to existing tidal creeks. Thalweg depths, particularly for
                  the St. Martin paleochannel, are much shallower than the previously projected depths
                  based on well log and bridge boring data. The nature and age of the surface defined by
                  the reflector and the associated fill sequences seen in the seismic records remains to be
                  resolved.   Additional cores penetrating the reflector need to be collected to define and


                                                               10








           date these sediment sequences.

                  Overall, the shallow bay sediments are very silty. Although no textural trends are
           apparent in vertical sequence of the sediments, the sediments generally- become coarser
           in an easterly direction across the bays. This trend is a result of SAND being transported
           into the bays from the ocean side of Fenwick Island.

                  Values for nitrogen, carbon and sulfur contents for most of the bay sediments are
           within the range expected for marine sediments. Nitrogen, carbon and sulfur contents are
           strongly related to the texture of the sediments, with higher values associated with finer-
           grained sediments. Extreme values were obtained from peat and peaty sediments which
           yielded carbon and sulfur contents up to 30% and 5.3%, respectively. Generally, carbon
           contents decrease with depth as sulfur contents increase, the relationship predicted by
           sulfate reduction processes that occur naturally in the sediments under anoxic conditions.

                  Results of metal analyses yield no excessively high metal concentrations.
           Enrichment factor (EF) values relative to average crustal rock were calculated to be
           greater than one for Zn and Cr and less than one for Cu, Mn and Ni. The low values,
           particularly for Mn, suggest that the reference material used to calculate the EF values
           probably does not adequately represent the sediments found in the study area. Although
           the reference material used is questionable, the calculated enrichment factors for Isle of
           Wight and Assawoman Bays are similar to enrichment factors for other Atlantic coast
           bays in non-industrial regions (Sinex and Helz, 1981).

                  Enrichment factor values reveal some significant trends in metal behavior within
           the sediment column. Plots of EF values versus depth in core reveal that the surficial
           sediments compared to deeper sediments are slightly enriched with all metals except Mn
           which showed no change in enrichment. The greatest increase in EF values are for Zn
           and Cu which show 2-fold increases. EF values decrease downcore, generally leveling
           off between 20 to 30 cm. The EF values for sediment below 20 to 30 cm are *interpreted
           to represent historical or background levels before anthropogenic influence.

                  A second technique to assess and compare metal levels correlates metal
           concentrations to textural composition. The results of this second technique generally
           corroborate the observations based on enrichment factors. The second technique indicates
           that Zn and Cu levels in surficial and near surface sediments are twice that of background
           levels. On the other hand, Cr and Ni levels in the upper sediment column (< -30 cm
           depth) are within background levels, suggesting that there is little or no anthropogenic
           input of Cr and Ni in the study area. Because this second technique is based on
           correlation of metal concentrations with the textural composition of sediments, the results
           characterize the study area more realistically than enrichment factor values.










                                               RESULTS AND DISCUSSION,



                   SEISMIC PROFILES


                          Maximum penetration of the 7.0 kHz signal was between 6 to 7.5 in (-20 to 25
                   ft).  The penetration was less in shoaling areas where bottom sediments were
                   predominately SAND. Shallow water depths combined with hard (sandy) bay bottom
                   resulted in strong multiples obscuring the detail in the seismic records. The better seismic
                   records were collected in the western and central portions of the bays where finer-grained
                   sediments predominate. Extensive sand deposits representing washover fans or tidal deltas
                   cover a large portion of the eastern and southern margin of the two bays. The seismic
                   records collected in these areas show little or no subsurface detail (structure).

                          Shallow paleochannels are seen in many of the seismic profiles. Maximum depths
                   of the channels range from -7 to -8 in MSL. Paleochannel floors and walls are very
                   hummocky in areas as illustrated in Line 3 (Figure 2). Paleochannel walls extend up to
                   the sediment surface converging with the present bay bottom.

                          The reflector defining the geometry of the paleochannels is very prominent,
                   marking the maximum penetration of the acoustical signal. The surface defined by this
                   reflector is interpreted to represent a pre-transgression surface, portions of which formed
                   directly on Pleistocene deposits (Sinepuxent Formation). The reflector is intercepted by
                   several dredged areas on the eastern side of Assateague Bay (Figure 3). These deep areas
                   are results of dredging for backfill to build up areas in Ocean City for development. Peat
                   had been recovered from the bottom of these dredged holes during past benthic studies
                   (Al Wesche, pers. comm.).

                          The contours which show the structure of this pre-transgression surface are
                   presented in Figure 4. The structure details a portion of an earlier drainage system, age
                   of which is unknown. The paleodrainage represents ancestral extensions of Greys and
                   Roy Creeks and St. Martin River. Based on the trend of the deeper contours (-5 and -7
                   in), the paleochannel traced to Roy Creek extends laterally across Assawoman Bay,
                   passing beneath Fenwick Island just south of Montego Bay. Greys Creek paleochannel
                   extends down Assawoman Bay and into Isle of Wight Bay converging with the St. Martin
                   River paleochannel. The St. Martin/Greys Creek paleochannel appears to extend under
                   Fenwick Island between 50th and 55th Streets Oust south of Rt. 90 bridge).






                                                                12
















                                   i @Aldloi




                                          W
                             -d
                                  11;
                                           JU                     1"T
                                                                       n@    At
                                                         FT

                             EAST                          TIME FIX                         WEST
                             0-    312     313    @4       315    316     317            319  E1 0
                                  SEDIMENT SURFACE (BAY BOTTOM)
                             3-                       MODERN LAGOONAL MUDS                      0

                          W                                                                       W
                             6--          BASAL FILL                                              w
                          W                                                                       LL
                          45   -                                                                  z
                          z

                                    PLEISTOCENE DEPOSITS                                          IL
                          a-                                                                      W
                          W                                                  500 METERS
                          0  12.-
                             15-- LINE .3                                                       50
           Figure 2.  A) West end of record for seismic line 3 which crosses the widest part of Isle of Wight Bay. B) Interpreted section
                      showing prominent reflector defining paleochannel and pre-transgression surface. Time of day and latitude and
                      longitude coordinates for time fixes are listed in Appendix 1.


















                                         :3
                                                            6'





                        WH
                                   14'.1v



                                                           4


                           L
                                                                           t:

                          WEST                    TIME FIX                  EAST
                                   2     3      4     5     6      7     8  9
                  B       0-                    1     1     1      1     1  1 0
                                            EDIMENT SURFACE
                          3v. -                                   DREDGED
                                                                  HOLE
                        W
                                                                                F_
                        W       PLEISTOCENE DEPOSITS                            LU
                                                                                W
                                                                                LL
                        z                                                       z

                                                                             __30


                        W
                                                                                W
                          12--                           430 METERS
                          15-- LINE 8                                         so
        Figure 3. A) Record for seismic line 8 crossing north Assawoman Bay. B) Interpreted section featuring cross-section of a
                 dredged hole adjacent to Montego Bay Trailer Park located on the bay side of North Ocean City, Maryland. Note that
                 the dredged hole cuts below the reflector.










              CONTOUR INTERVAL
                     1 METER
              (DEPTH BELOW MSL)                 54


                                              4
                                             D

                             C)
                                                     5             38* 26-


                                        5       4









                                                5
                                                6


                                             6







                                            6

                                      5     7


                              4
                                5 '6         5


                                                                   38* 22'-


                                            0050



              0         2    3    4

                   KILOMETERS


                       75* 08'                      75* 04'


        Figure 4. Contour of surface defined by the prominent reflector seen in seismic
        profiles. The reflector is identified in Figures 2 and 3.


                                         15








                         Measured thalweg depths of the St. Martin paleochannel are 7.5 to 8 rn below
                  MSL, much shallower than the +30 m depth projected by Halsey (1978) and Toscano el
                  aL (1989). Assuming that the base of the paleochannel is deeper, then this reflector
                  marks the lower boundary of some intermediate Holocene channel-fill sequence.

                         A second very faint, planar, reflector is visible within most of the paleochannels
                  (Figures 2 and 3). This reflector marks the boundary between a lower fill sequence (tidal
                  creek or palustrine deposits) and the overlying modem lagoonal sediments.

                         Modem Holocene deposits (lagoonal muds) are thin over much of the western
                  portion of the bays. Thicknesses range from 0 to 6 m, with maximum thicknesses
                  corresponding to the central axes of the underlying paleochannels. Recent washover and
                  deltaic deposits are restricted to the eastern and southern end of the study area. The
                  thickness of these deposits could not be determined from the seismic data.




                  SEDIMENT TEXTURE


                         Sediment textures are discussed in terms of the lithosomes outlined by
                  Chrzastowski (1986) for sediments in Rehoboth and Indian River Bays, Delaware.
                  Chrzastowski divided the Holocene deposits into four major lithosomes: 1) flood-tidal
                  delta/barrier sand; 2) lagoonal mud; 3) marsh mud; and 4) tidal stream mud.

                         Most sediment samples contained a significant percentage of SILT, averaging 44%
                  for all samples. This reflects the silty character of the Sinepuxent Formation, a major
                  source of sediment to the bays. Averages for SAND and CLAY contents were 3 1 % and
                  25% respectively. CLAY contents were higher for the cores collected in the tributaries
                  (Stations 7 and 12- refer to Figure 5 for core locations). SAND contents were higher in
                  cores collected toward the eastern side of the bays. Sediments with higher SAND
                  components are expected along the southern and eastern margins of the bays. SAND is
                  transported into the bay either by eolian and washover processes from the ocean side of
                  Fenwick Island or through the inlet by tidal processes. The amount of SAND transported
                  and deposited by these processes diminishes significantly as distance from the source
                  areas increases.


                         Cores collected at stations 1, 4, 6, 9 and 10 consisted entirely of modem lagoonal
                  sediments. These cores were very similar in appearance and texture, containing dark olive
                  grey to greenish black SAND-SILT-CLAYS and CLAYEY SILTS. SAND contents range
                  from less than 5 to 30% SAND fractions are well to very well sorted, very fine SAND.



                                                              16








                  Xeroradiographs of the cores reveal varying levels of bioturbation (i.e. sediment
           mixing by biogenic activity). Burrows of bivalves and polychaetes are common.
           Mercenaria mercenaria, Crassostrea virginica, and Nassarius sp. were found in many the
           cores with Nassarius s being the most common shell encountered. Distinct laminae are
                                  P_
           evident in radiographs for station I (mouth of Greys Creek) and station 10 (bayward of
           St. Martin River) (Appendix H). Visually, the laminae were not apparent. The laminae
           indicate that sediment have not been disturbed or mixed by biogenic activity.

                  Based on the low bioturbation levels, core 1 was selected for analysis      of 21OPb
           activity to determine sedimentation rate. The analysis was done by the University of
           Maryland Horn Point Environmental Laboratory. Based on        21OPb activity, sedimentation
           rate for core I was estimated to be 0.3 to 0.4 cm/yr (Jeffrey Cornwell, unpubl. data).
           This sedimentation rate is within the range determined by Chrzastowski (1986) for mid-
           bay, mud dominated area in Rehoboth Bay and Indian River Bay in Delaware. Based on
           21OPb and 117CS activity analyses, sedimentation rates were 0.26 cm/yr for Rehoboth Bay
           and 0.57 cm/yr for Indian River Bay. These rates agreed with those determined by
           bathymetric comparisons of the Delaware bays.

                  The 0.3 to 0.4 cm/yr sedimentation rate for Isle of Wight Bay is typical of rates
           for eastern U.S. coastal bays. Atlantic and Gulf coast bays usually have sediment
           accumulation rates ranging from 0.4 to 0.5 cm/yr (Rusnak, 1967). These sedimentation
           rates also match the present rate of sea level rise which is 0.33 to 0.39 cm/yr (Belknap
           and Kraft, 1977).

                  The core collected at station 2 may have penetrated the pre-transgression surface.
           The location of station 2 corresponds to time-fix 1036 on Seismic Line 6. The seismic
           record shows the pre-transgression surface to be very shallow, at -2.5 m MSL, at this
           location. The bottom of this core (-2.8 m MSL) contained peaty mud. A wood fragment,
           identified possibly as Oak (Quercus) rootwood (Center for Wood Anatomy Research, U.S.
           Forest Products Lab., written comm.) was recovered at -2.9 m.

                  Cores I I and 13 were collected along the eastern edge to the bays.         Core I I
           contained greenish black to dark olive grey, organic SILTY SAND, representing tidal flat
           sediments. Core 13 was collected in a shallow shoaling area and consisted of light tan
           to medium olive grey, medium to fine SAND.

                  Cores 7 and 12 were collected in St. Martin River and Turville Creek, respectively.
           These cores consisted of dark grey CLAYEY SILT and SILTY CLAY. The sediments
           from these cores contained the least amount of SAND compared to other cores collected
           for this study. Based on lower SAND content and higher CLAY contents, the sediments
           are classified as tidal stream deposits.


                                                        17








                          Core 14 was collected in a marshy area near Horn Island located in southern Isle
                   of Wight Bay. The sediments contained in this core consisted of interbedded layers of
                   dark olive grey to brownish black SAND-SILT-CLAY, SILTY CLAY, and CLAYEY
                   SILT. Peaty material was abundant, increasing with depth. Several sediment samples
                   taken from this core consisted entirely of peat material and were not analyzed for SAND-
                   SILT-CLAY components.




                   WATER CONTENT


                          Correlation analyses of water contents as well as SAND, SILT, CLAY, carbon,
                   nitrogen and sulfur contents for all sediment samples were performed to detect any
                   significant associations between variables. The correlations were done using Pearson
                   product-moment technique (STSC, Inc., 1986). The resulting correlation matrix is
                   presented in Table II. Samples from core 14 were not included in the correlation analysis
                   since many of the samples contained high amount of peat and plant debris and very little
                   inorganic material (sediment). These samples are not considered to be representative of
                   bay sediments.


                     Table H.     Correlation matrix for nitrogen, carbon, sulfur contents and sediment
                     textural data based on all core samples except station 14. Values-are Pearson
                     correlation coefficients (r). Significant levels for all values are less than 0.01
                     (critical value of r at 99% = 0.479).

                                                 %Carbon               %Nitrogen                %Sulfur

                          %Carbon                  1.000                     -

                         O/oNitrogen               0.852                  1.000                     -

                          %Sulfur                  0.677                  0.629                   1.000

                            .%H20                  0.770                  0.772                   0.834

                          %SAND                    -0.611                 -0.653                  -0.803

                            %SILT                  0.536                  0.583                   0.669

                          %CLAY                    0.609                  0.638                   0.857


                          Water contents of the core sediments ranged from       7.98% wet weight for SAND
                   (100% SAND) to 80.9% for SILTY-CLAY (54% CLAY). Water contents are strongly
                   associated with the CLAY component of the sediment as reflected by the high correlation.


                                                                18








           coefficient between percent water and CLAY content (r = 0.92). Associations between
           water content and SAND (r = -0.84) and SILT content (r = 0.66) are weaker.

                  Since the amount of water a sediment holds is strongly influenced by grain size,
           downcore variations in water content track variations in CLAY contents (refer to plots in
           Appendix III). Any downcore decrease in water contents due to compaction is not readily
           apparent.




           GEOCHEMISTRY


                  Results of the chemical analyses are listed in Appendix III. The results versus
           depth in core were also plotted and are presented along with plots of the other variables
           (water content, SAND, SILT, CLAY components, and carbon, sulfur and nitrogen
           concentrations) inAppendix III.

                  All measured parameters were included in correlation analysis. Two correlation
           matrices were generated.     The first matrix, correlations between sediment textural
           components and nitrogen, carbon and sulfur (NCS) contents, has been presented in Table
           II.   The second matrix, correlations between m        etal concentrations and textural
           components, is presented in Table III. The correlations between carbon, nitrogen, and
           sulfur contents and metal contents were moderate to weak (r < 0.7). The poor correlations
           reflect the different geochemical processes that control the behavior of these chemical
           components. These correlation coefficients are not presented in this report.




                                               Nitrogen Content

                  Nitrogen contents in sediments range from 0 to 1.39% and averaged 0.22%. The
           highest nitrogen values were found in sediment containing peat material (Core 14).
           Correlation analysis of nitrogen, carbon and sulfur contents with textural data show that
           nitrogen content of sediments is strongly correlated with carbon content (correlation
           coefficient (r) = 0.852, Table II). The correlation coefficient is higher if correlation
           analysis include core 14 samples (r = 0.97). The strong relationship between nitrogen and
           carbon reflects the fact that nitrogen comes primarily from organic geopolymers found in
           the sediment (Hill el aL, 1992). Therefore, nitrogen is expected to maintain a constant
           proportionality with carbon content. Ratios of nitrogen to carbon range from 0.05 to 0.23
           with a mean value of 0. 10 ï¿½ 0.05 which is slightly lower than the ratio of 0. 113 obtained
           from sediment cores collected in the Chesapeake Bay (Hill et aL, 1992). The lower ratio


                                                       19









                  is attributed to the fact that sediments having extremely low or no nitrogen contents were
                  included in the calculation of the mean ratio.




                                                      Carbon Content


                         The carbon found in sediments consists of both inorganic and organic components.
                  Studies of the Chesapeake Bay sediments have shown that inorganic carbon        component
                  is minor, contributing less that 18% to the total carbon content (Hennessee et aL, 1986;
                  Hobbs, 1983). Shell fragments accounted for the bulk of inorganic carbon measured in
                  Chesapeake Bay sediments. However, shell fragments were not as abundant in the coastal
                  bay sediments compared to Chesapeake Bay sediments. Therefore, it is assumed that
                  inorganic carbon contributes little to the total carbon measured in the coastal bay
                  sediments


                         Total carbon contents measured in the core sediments range from 0.02 to 30.0%
                  with a mean value of 2.8%. The highest carbon values were obtained from peaty
                  sediments sampled from core 14. Values for the peaty samples range from 8.5 to 30.0%
                  carbon. Carbon contents for surficial sediments range from 0.25 to 3.65% about a mean
                  value of 1.83% which are within the range of those values reported for the Chesapeake
                  Bay (range = 0 to 10.5%; mean = 2.1%; Hennessee el aL, 1986) and for other pristine
                  estuaries (Folger, 1972). Folger observed that organic carbon contents for fine-grained
                  sediments from estuaries not subjected to high pollution seldom exceeded 5% and were
                  often less than 3%. He attributed anomalously high values for carbon to plant debris.
                  For example, peat deposits from Albemarle Sound yielded carbon content values as high
                  as 20 to 30%.


                         Correlation analysis reveals a moderately strong association between carbon content
                  and % water (r = 0.73) (Table II). Correlation coefficients between carbon content and
                  SAND, SILT, CLAY contents are moderately small (r = -0.61, 0.54 and 0.61,
                  respectively), indicating that carbon is not associated with any particular size fraction.
                  The poor correlations may be related to the nature of the carbon. For example, in
                  northern Chesapeake Bay, carbon is most strongly associated with SILT, reflecting the
                  terrigenous nature of the carbon, composed of coal particles and plant detritus (Hennessee
                  et A, 1986). In the middle Chesapeake Bay where the main source of carbon is
                  planktonic detritus, the strongest, correlation is between carbon and CLAY content (r =
                  0.91). The poor correlation between carbon content and size fraction in the coastal bays
                  suggests a more complex relationship. The carbon content reflects a combination of both
                  terrigenous and planktonic sources.



                                                              20










                                                 Sulfur Content


                   Sulfur in sediments is found primarily as inorganic metal sulfide   s and elemental
            sulfur. These sulfur species form as a result of a bacterially mediated reaction during
            which organic carbon is oxidized using dissolved sulfate (S04-) from seawater as an
            oxidant (Berner, 1967, 1972; 6oldhaber and Kaplan, 1974). During the process that
            occurs under anaerobic conditions, sulfate is reduced to sulfide. The sulfide reacts with
            ferrous iron (Fe@2) forming an iron monosulfide precipitant which further reacts with
            elemental sulfur to form FeS2 (pyrite and its polymorph, marcasite) (Berner, 1970). As
            a result of this process, sulfur is enriched and preserved in the sediments as the amount
            of organic carbon is depleted.

                   Total sulfur contents of coastal bay sediments range from 0 to 5.28% about a mean
            of 1.05%. Sulfur contents of surficial sediments range from 0.04 to 1.48%, averaging
            0.58%. The range and mean for surficial samples are similar to those values reported for
            the Chesapeake Bay (Hennessee et aL, 1986; Hobbs, 1983). As with nitrogen and carbon
            contents, core 14 samples containing peat yielded the highest sulfur contents, ranging
            from 1.43 to 5.28%.


                   The ratio of carbon to sulfur (C/S) decreases with depth in most of the cores. This
            decrease is expected as sediments tend to become enriched with sulfur over time (i.e.
            increased depth of burial) while carbon is metabolized. The C/S ratios average 2.8 for
            all samples. This value is identical to the C/S ratio for modem marine sediments, 2.8 ï¿½
            1.5 (Bemer and Raiswell, 1984). The C/S ratios for the peaty sediment are much higher
            indicating that a relatively small proportion of carbon has been metabolized to produce
            sulfide. Most carbon in peat is plant detritus which is less susceptible to bacterial decay
            compared to algal debris (Goldhaber and Kaplan, 1975).

                   Results of correlation analysis show a strong association between sulfur and CLAY
            content (r   0.86) and water content (r = 0.83). Correlation between sulfur and SILT is
            weaker (r   0.67). The.strong correlation between sulfur and CLAY content suggests that
            sulfur is best preserved in clayey sediments as opposed to silty sediments. The more
            reactive carbon, planktonic detritus, is also associated with CLAY. Clayey sediments
            typically have high water contents which accounts for the strong correlation between
            sulfur and water content. These results are consistent with those of the Chesapeake Bay
            (Hennessee et aL, 1986).

                   Monosulfides, measured in cores I and 10, decrease sharply between 15 to 20 cm
            below the sediment surface. This sharp decline in monosulfide indicates a change in the
            sedimentation rate.




                                                        21










                                                               Metals


                           Sediment samples have metal concentrations (refer to Appendix III, Table XI) of
                   the same order of magnitude as those reported from a previous study (Allison, 1975).
                   However, since Allison did not analyze sediments for Fe, Al or textural parameters
                   (SAND-SILT-CLAY content), his results are difficult to interpret. Also, quantitative
                   comparison of Allison's data to other data sets can not be done. Generally, Zn and Cu
                   concentrations from this study are within the range of those reported by Allison. Cr
                   concentration are overall higher than Allison's values. The differences in Cr levels
                   between the two studies are due to the different analytical methods used.

                           Correlation analysis reveals that all elements are significantly correlated with one
                   another (Table III). The highest correlations are between Fe and Cr (r = 0.99), Fe and
                   Ni (r = 0.976) and Fe and Mn (r = 0.941), Cr and Ni (r = 0.985), and Cu and Zn (r =
                   0.936). There are also high correlations between CLAY content and Cr, Fe, and N1.
                   These metals typically are associated with clay minerals (Cantillo, 1982). These metals
                   are either components of the mineral lattice structure or absorbed onto clay surfaces. Clay
                   minerals comprise a significantly large portion of the fine (CLAY size) sediment fraction.
                   In general, metal concentrations show a strong inverse relationship with SAND contents
                   indicating that the trace metals are contained in the mud fraction (SILT and CLAY).


                     Table 111.    Correlation matrix for trace metal concentrations and sediment
                     textural data based on all core samples except station 14. Values are Pearson
                     correlation coefficients (r).. Significant levels for all values are less than 0.01
                     (critical value of r at 99%    0.479).

                                         Cr          Cu           Fe           Mn           Ni           Zn

                           Cr          1.000          -

                           Cu          0.689        1.000          -

                           Fe          0.993        0.639        1.000           -

                           Mn          0.943        0.550        0.941        1.000          -

                           Ni          0.985        0.712        0.976        0.932        1.000          -

                           Zn          0.807        0.936        0.76@        0.704        0.817        1.000

                      % SAND           -0.915       -0.728       -0.908       -0.837       -0.907       -0.790

                       % SILT          0.785        0.701        0.772        0.717        0.790        0.732

                      % CLAY           0.944        0.630        0.945        0.864        0.915        0.729



                                                                 22











            Enrichment Factors


                  In order to reduce the effect of grain size, metal concentrations are discussed in
            terms of enrichment factors (EF). The use of enrichment factors also allows for
            comparisons of sediments from different environments and the comparisons of sediments
            whose trace metal contents were obtained by different analytical techniques (Cantillo,
            1982; Hill el aL, 1990; Sinex and Helz, 1981).


                  Enrichment factor is defined as:


                                              EF(x)     (XIFe),.,k
                                                       (X1Fe),.ef,,nc,



                           where:
                                 EF(, is the enrichment factor for the metal X;

                                 X1Fe(,,..,k) is the ratio of the concentrations of
                                 metal X to Fe in the sample; and

                                 XlFe (ref-) is the ratio of the concentrations of
                                 metal X to Fe in a reference material, such as an
                                 average crustal rock.

                  Fe is chosen as the element for normalizing because anthropogenic sources for Fe
            are small compared to natural sources (Helz, 1976). Taylor's (1964) average continental
            crust is used as the reference -material. Average crustal abundance data may not be
            representative of the coastal bay sediments because there is a higher proportion of SAND
            in the bay sediments compared to the average crustal rock. However, abundance data is
            useful as a relative indicator.


                  Enrichment factors for the five metals in the core sediments are listed in Appendix
            III (Table XIII). The bay sediments are enriched in Cr and Zn with respect to crustal
            rock. For surficial sediments, the average enrichment factor values for Cr and Zn are 1.5
            and 2.6. respectively. Sediments generally are not enriched in Cu, Mn, and Ni relative to
            average crustal rock. EF values for these three metals are less than one. These low
            values do not necessarily signify the area is depleted in these metals, but instead reflect
            the unsuitability of the reference material.


                                                        23








                           EF values for Cr, Mn and Ni in surficial samples increas6 very slightly toward the
                    eastern side of the bays. Additional sampling stations are needed to determine the
                    significance of this trend.

                           Most cores show a downcore decrease in EF values for all metals except Mn (refer
                    to plots in Appendix III). EF values are highest in the upper 20 cm of sediment column
                    and level off downcore. This decrease in the enrichment factors suggests that metal
                    contents in the upper sediment column reflect anthropogenic input above a background
                    level. Metal contents in sediments deeper than 20 to 30 cm represent pristine, natural
                    levels before human influence. The 20 to 30 cm depth represents approximately 60 to
                    100 years assuming that the sedimentation rate of 0.3 to 0.4 cm/yr (based on              21OPb
                    activity) represents the sediment accumulation rate in the two bays.

                           Relative decrease in EF values varies for the different metals. Cu and Zn show the
                    largest downcore decrease in enrichment, with surficial sediments having twice the
                    enrichment factor of the deeper sediments. Ni and Cr factors decrease 10% to 30%.
                    downcore. EF values for Mn, on the other hand, do not vary with depth suggesting that
                    measured'Ievels come entirely from natural sources with very little anthropogenic input.

                           Enrichment factors referenced to/ Tayl&s average crust have been used by Sinex
                    and Helz (1981) to compare Chesapeake Bay sediments to various east and gulf coast
                    estuaries. The comparisons are listed in Table IV and include the average enrichment
                    factors for surficial sediments analyzed in this study. The coastal bay sediments yielded
                    EF values similar to other estuaries not subjected to heavy industrial activities.
                    Enrichment factors of Cr, Cu, Mn, and Ni are near unity for these estuaries. Assawornan
                    and Isle of Wight Bays are enriched in Zn, although not as high as some other estuaries.
                    Sinex and Helz (1981) suggested that the large enrichment factors for Zn could be
                    attributed to one of two possibilities. 1) Zn values for Taylor's average crustal rock are
                    too small to be representative of eastern United States sediments. 2) Anthropogenic
                    contamination of Zn is ubiquitous. In Maryland's coastal bays, it is likely that Zn
                    enrichment comes from anthropogenic contamination. Zn is widely used as a sacrificial
                    anodizing metal on boat hulls and metal crab traps (Al Wesche, pers. comm.). Similarly,
                    Cu is also ubiquitous but not at the same level as Zn. Sources of Cu include marine
                    paints widely used until recently, and chemical compounds used to impregnate wood for
                    marine use.











                                                                  24









             Table IV.    Comparisons of average enrichment factors in various East and Gulf
             Coast estuaries. Enrichment factors are relative to the average earth's crust (Taylor,
             1964). N is the number of samples used to obtain the average factors. The table
             was modified from Sinex and Helz, 1981.

                                                 Cr       Cu       Mn         Ni       Zn

             Narragansett Bay                     3        6         1         1       6       (1)
             (Goldberg et aL, 1977)
             Hudson Estuary                       -        2         2         -       4       (37)
             (Williams et aL, 1978)                                                         1
             Delaware Bay                         3        2         -         13      10     (124)
             (Bopp and Biggs, 1973)
             Chesapeake Bay                       1        1         2         1       5      (177)
             (Sinex and Helz, 1981)
             Baltimore Harbor                     7        10        1         1       20     (194)
             (Villa and Johnson, 1974)
             Isle of Wight/Assawoman              I        I         1         1       3       (14)
             Bays (this study*)
             Savannah River                       I        I         I         F       1       (5)
             (Goldberg et aL, 1978)
             Mobile Bay                           -        1         1         -       4       (8)
             (Brannon et al., 1977)
             Mississippi Delta                    -        I         1         1       3       (72)
             (Trefry and Presley, 1976)
             Galveston Bay                        4        2         3         2       6       (44)
             (Hann and Slower, 1972)
             San Antonio Bay                                                   1       3       (51)
             (Trefry and Presley,, 1976)

                Averages based on surface samples (top of cores) only.







                                                       25










                  Variation from Historical Norms


                         The "degree" of metal enrichment in sediments relative to a regional norm or
                  historical levels can be assessed by correlating trace metal concentrations with grain size
                  composition (Hennessee et al, 1990; Hill et aL, 1990). Based on the downcore decrease
                  in enrichment factor values, metal concentrations of sediments below 30 cm in the
                  sediment column are interpreted to represent the historical norm for the coastal bays.
                  Metal concentration values for these sediments (i.e. sediments below -30 cm) were fitted
                  to the following equation:

                                           X = a (SAND) + b (SIL7) + e (CLA 1)                           (2)

                                 where:
                                        X is the metal of interest;

                                        a, b, and h are the proportionality coefficients
                                        determined for the SAND, SILT and CLAY
                                        components, respectively; and

                                        SAND, SILT, and CLAY are grain size fractions
                                        of the sediment sample.

                         Using an algorithm developed by Marquardt (1963), least square coefficients were
                  estimated. The results are presented in Table V. The correlations are excellent for all of
                  the metals. The values for the coefficients indicate that CLAY fractions account for a
                  significant amount of the metal concentrations.


                    Table V.     Least squares coefficients for metal data. Metal concentration values
                    for sediments sampled below 30 cm in cores were fitted to Equation 2. Core 14
                    data were not included in the data set.

                                                         Estimates of coefficients

                                   Cr           Cu           Fe           Mn            Ni           Zn

                     SAND         5.4905     0.97712     0.12284        37.682       3.43225      5.158017

                      SILT      32.8062        5.83       1.24878      166.7049      13.37438     25.15979

                                173.0266      14.374      7.8523       691.4095      50.4597      127.3579

                       R2         0.9505     0.9042       0.9536       0.823282       0.9006      0.92221


                                                               26








                  By substituting the least squares coefficients from Table V in equation 2,
           "predicted" metal concentrations were calculated for all of the sediments. These predicted
           metal concentration values represent the expected historical or background levels of metals
           based on grain size composition of the sediment. To determine variations from historical
           norms, the predicted metal concentrations were compared to the measured values using
           the following equation.

                                     Vailationx     Measuredx - Predicted,                        (3)
                                                           Predictedx



                  N egative values indicate depletion and positive values indicate enrichment relative
           to background. levels.

                  Variation values calculated for sediments below 30 cm in the sediment column
           were analyzed according to Gaussian statistics. Variation values for all metals exhibit'
           near-normal distributions with mean values close to zero. Mean variation values and
           standard deviations for each metal are presented in Appendix III (Table XIV). The
           standard deviation (cr), a measure of dispersion of values, provides a convenient means
           to identify significantly high or low variation values. For example, in a normal
           distribution, 68% of the values fall within I a of the mean; 95.5% of the values fall within
           2a of the mean. Values greater than 3a are considered significant beyond the natural
           population dispersion.

                  The variation values for each metal were calculated for. all core sediments and are
           presented in Appendix III (Table XV). Variation values exceeding 3a are highlighted in
           the table. Compared to enrichment factors, variation values reveal similar trends in Cu
           and Zn behavior. Variation values for Cu and Zn for surficial and near surface sediments
           (sample depths < 20 cm) for all cores except core 13 exceed 3a levels. Surficial
           sediments contain twice the amount of Cu and Zn over background levels (historical
           levels). Cr, Fe, Mn and Ni do not vary appreciably from background levels in the
           sediment column. With the exception of core 14, variation values for Cr, Fe, Mn, and N1
           for surficial sediments at all stations fall within 2a levels. The Fe and Mn contained in
           the sediment are attributed almost entirely to natural sources and, therefore, are not
           expected to show any increase (or decrease) over historical or background levels. On the
           other hand, based on the results of enrichment factor analysis, higher variation values
           were expected for Cr and N1. However, the calculated variation values for Cr and Ni fall
           within 2a levels, suggesting that these two metals also come from natural sources and not
           from anthropogenic contamination.


                                                        27










                                                          METHODS



                   SEISMIC PROFILING


                          Shallow seismic surveys were conducted in April, 1992. Approximately 33
                   kilometers of seismic profile surveys were collected. Track lines for the seismic surveys
                   are shown in Figure 5. Seismic profiles were collected using a Raytheon subbottom
                   profiler, -Model DE 719 Survey Fathometer, with a PTR 106 C-1 Transceiver, set at a
                   frequency of 7 kHz. A Loran-C System was used for navigation. Loran time difference
                   pairs (TD's) were recorded every two minute and referenced to time fix marks on the
                   seismic record. Loran TD's were converted to geographic coordinates using a conversion
                   program developed for the Chesapeake Bay (Halka, 1987). The corrected geographic
                   coordinates were further ad usted for the study area by adding correction factors of -5.26"
                   latitude and +1.70" longitude.




                   CORING TECHNIQUES

                          Cores and surficial sediments were collected during July, 1991. Location of the
                   fourteen (14) sampling stations are shown in Figure 5. Positions of these stations were
                   determined by a Loran-C Navigational System.

                          Most cores were collected within the central portions of the bay to insure vertical
                   sampling of fine-grained sediments representative of modem lagoonal muds. However,
                   other depositional environments such as fringing marsh, tidal stream and tidal shoal areas
                   were also sampled to compare physical and chemical characteristics of sediments from the
                   different depositional environments.

                          In water depths greater than L5 in (5 ft) sediment cores we    re collected using a
                   Benthos Gravity corer, Model 92171, fitted with clear cellulose acetate butyrate (CAB)
                   liner tubes, 6.7 cm in diameter. At three stations (93, 5, and 8), the bottom was too hard
                   (san dy) for the corer to penetrate. As a result, only surficial sediment samples were
                   collected at these stations. In waters depths shallower than 1.5 m cores were collected
                   using a portable vibraconing unit similar to the unit described in Finklestein and Prins
                   (1981). CAB tubes were used as core liners. As soon as the cores were collected, they
                   were cut at the sediment-water interface and capped. Once in the laboratory, the cores
                   were refrigerated at 4*C until analyses.




                                                               28









           LABORATORY ANALYSES


                               Xeroradiography and Initial Core Processing

                  Prior to analyses, the cores were X-rayed using a TORR-MED medical X-ray unit.
           Instrument settings varied depending on the composition of the cores. The most
           frequently used settings ranged between 80 to 90 kV at 5 mA for 30 to 50 seconds.

                  Latent X-ray images of the cores were developed using a dry processing technique
           (xeroradiography) invented by the Xerox Corporation. For the developing process, the
           negative mode setting was used, producing a radiograph in which denser material such
           as sand or shells show up as white images. Composites of the xeroradiographs are
           presented in Appendix H.

                  After X-raying was completed, each core was extruded from the plastic liner, split,
           photographed and visually described noting any sedimentological structures and
           lithological changes. Core logs are presents in Appendix H.

                  Sediment samples were taken at specific locations in the cores based on the visual
           and radiographic observations.


                                              Textural Analyses

                  Sediment samples were analyzed for water content and grain size (SAND, SILT,
           CLAY content). Water content was calculated as the percentage of water weight to the
           weight of the, wet sediment using equation 4.


                                                          W
                                             % Water      ' * 100                                (4)
                                                          Wt



                         where:    W,, is the weight of water; and

                                   W, is the weight of wet sediment.

                  Water content was determined by weighing 30 to 50 grams of sediment, drying the
           sediment at 65'C, and then reweighing the dried sediment. Dried sediments were saved
           for chemical analyses (see Chemical Analyses section).



                                                       29







                                                         1@01


                                                                     - -- -        - - -        DE
                                                                                                MD


                                                                          A4
                                                                      q...... R. V,

                                                                                                  38* 2V



                                                               A,_    2.   ...
                                                            ......          Ito


                                                                 ASSAWOMA
                                                                       BAY



                                                               0
                                                                   :6
                                                                6@: A 4,
                                                                PT.    5
                                  8A       A7         ISLE 0
                                                .90    WGHT
                                              Rt

                                                  vo@
                                                              0
                                                                  : all
                                                      A@      ........:
                                                                  .............
                                   .IVA
                                                          .................

                                                                                                  38* 22'-
                                                       ISLE OF
                                                                 y
                                                     W1 H







                                                               14
                                                              A
                           0            2      3       4

                                  KILOMETERS
                                                                        OCEAN CITY
                                       750108'                                75* 04'

                   Figure 5. Map of the track lines for seismic profile surveys with locations of core and
                  surficial sediment stations.


                                                              30








                  SAND, SILT and CLAY contents were determined using the textural analysis
           detailed in Kerhin et al. (1988). Sediment samples were first treated with 10% solution
           of hydrochloric acid (HCI) to remove carbonate material such as shells and then treated
           with a 6 to 15% solution of hydrogen peroxide (H202) to remove organic material. The
           sediments were then passed through a 62 micron mesh sieve separating SAND from the
           mud fraction.


                  Mud fractions were analyzed using a pipette technique to determine SILT and
           CLAY contents. Weights of the SAND, SILT and CLAY fractions were converted to
           relative proportions (weight percentages). The sediments were categorized according to
           Shepard's (1954) classification based on percent SAND, SILT and CLAY components.

                  SAND fractions were analyzed using a rapid sediment analyzer (RSA) (Halka et
           aL, 1980), obtaining graphic mean, inclusive graphic standard deviation (sorting) and
           inclusive graphic skewness.

                  The results of the textural analyses are listed in Appendix III.




                                              Chemical Analyses

                  Sediments dried for water content determination were analyzed for total elemental
           nitrogen, carbon and sulfur (NCS) contents and six metals. The dried sediments were
           pulverized in tungsten-carbide vials using a ball mill, then placed in Whirl-PakTm bags and
           stored in a desiccator.



           Nitrogen, Carbon, and Sulfur Analyses

                  The sediments were analyzed for total nitrogen, carbon and sulfur (NCS) content
           using a Carlo Erba NA1500 analyzer. Approximately 10 to 15 ing of dried sediment was
           weighed into a tin capsule. The exact weight (to the nearest gg) of the sample was
           recorded. To enhance complete combustion during the analysis, 15 to 20 ing of vanadium
           pentoxide MOO was added to the sediment. For estuarine and marine sediments, the
           optimum ratio of vanadium to sediment is 1. 5: 1. The tin capsule containing the sediment
           and vanadium pentoxide mixture was then crimped to seal and stored until analysis.

                   The sediment sample, contained in a tin capsule, was dropped into a combustion
           chamber where the sample was oxidized in an atmosphere of pure oxygen. The resulting
           combustion gasbs, along with pure helium used as a carrier gas, were passed through a


                                                       31








                   reduction furnace to remove free oxygen and then through a sorption trap to remove
                   water. Separation of the gas components was achieved by passing the gas mixture
                   through a chromatographic column. A thermal conductivity detector was used to measure
                   the relative concentrations of the gases.

                         The NA 1500 Analyzer was configured for NCS analysis using the manufacturer's
                   recommended settings.      As a primary standard, 5-chloro- 4-hydroxy- 3-methoxy-
                   benzylisothiourea phosphate was used. Blanks (tin capsules containing only vanadium
                   pentoxide) were run every 12 samples and standards. Replicates of every fifth sample
                   were run. As a secondary standard, a NIST reference material (NIST SRM 41646 -
                   Estuarine Sediment) was run every 6 to 7 samples. Table VI presents the comparisons
                   of the MGS results and the certified values for total carbon, nitrogen and sulfur contents
                   for the NIST standard. There is excellent agreement between the NIST values and MGS's
                   results.


                    Table VI.      Results of nitrogen, carbon, and sulfur analyses of NIST-SRM 91646
                    (Estuarine Sediment) compared to the certified or known values. MGS values were
                    obtained by averaging the results of all SRM analyses run during this study.

                         Element Analyzed              Certified Values*               MGS Results
                                                         (% by weight)                  (this study)

                             Nitrogen                        0.211                      0.21 ï¿½0.01

                              Carbon                          1.72                      1.71 ï¿½0.12

                               Sulfur                        0.96                       0.99 ï¿½0.08


                      The value for carbon is certified by NIST. sulfur value is the non-certified value reported by NIST. 'Me value of nitrogen was
                    obtained from repeated analyses inhouse and by other laboratories (Haake Buchler Labs and U.S. Dept of Agriculture).




                   Monosulfide Analyses

                          Monosulfides (acid volatile sulfides) were determined using a method adapted from
                   Berner (1964, 1970). Wet sediment samples were acidified to produce hydrogen sulfide
                   (H2S), purged with oxygen-free nitrogen gas (N2), and trapped in a solution of zinc
                   sulfate-ammonium hydroxide which converted the H2S to zinc sulfide (ZnS). The ZnS
                   was then re-acidified, producing 112S, the amount of which was determined by iodometric
                   titration.





                                                               32









           Metal Analyses

                  Sediments were analyzed for six metals: chromium (Cr), copper (Cu), iron (Fe),
           manganese (Mn), nickel (Ni), and zinc (Zn). These metals were selected for several
           reasons. 1) These metals are non-volatile. As opposed to volatile metals, these metals
           are less likely to be lost during analytical procedures used in this study. 2) Studies have
           shown that these metals can be used as environmental indicators (Hennessee et aL, 1990;
           Hill, 1984; Cantillo, 1982; Sinex and Helz, 1981). 3) Comparable data for these metals
           are available for the Chesapeake Bay (Cantillo, 1982; Helz el aL, 1982; Hill et aL, 1985;
           and Sommer and Pyzik, 1974) and for other estuaries (Sinex and Helz, 1981).

                  Concentrations for the six metals were determined using a microwave digestion
           technique, followed by analyses of the digestate on an Inductively Coupled Argon Plasma
           unit (ICAP). The microwave digestion technique is detailed in Appendix IV.

                  A Thermo Jarrel-Ash Atom Scan 25 sequential ICAP was used for the metal
           analysis. The wavelengths and conditions selected for the metals of interest were
           determined using digested bottom sediments from the selected sites in the Chesapeake Bay
           and reference materials from the National Institute of Standards and Technology (NIST
           SRM #1646 - Estuarine Sediment; NIST SRM #2704 - Buffalo River Sediment) and the
           National Research Council of Canada (PACS-1 - Marine Sediment).

                  The wavelengths and conditions were optimized for the expected metal levels and
           the sample matrix. Quality control was maintained using the method of bracketing
           standards (Van Loon, 1980). Blanks were run every 12 samples. Replicates of every
           tenth sample were run. A set of reference materials (NIST 91646, NIST #2704, and
           PACS-1) was analyzed every ten to fifteen samples.

                  Results of the analysis of the three standard reference materials are compared to
           the certified values in Table VII. The MGS's results indicate better than 90% recovery
           for all of the metals except Mn. The lower recovery values for Mn (for NIST SRM #1646
           and PACS-1) may be due to incomplete digestion during sample preparation.











                                                        33









                    Table V11.      Results of metal analyses of standard reference materials compared
                    to the certified values.

                                   Certified Values                          MGS Results

                                  BR* ES* PAC*              BR*      %        ES*       %      PAC*        %
                                               I                   recovery          recovery          I recovery
                        Cr        135      76     113        128    94.6     77       94.5       107      94.5
                      (gg/g)      ï¿½5       ï¿½3     ï¿½8       ï¿½2.21            ï¿½234               ï¿½2.83

                        Cu        98.6     IS     452       94      95.3      16      91.2       431      95.3
                      (gg/g)      ï¿½5       ï¿½3     ï¿½16      ï¿½1.11            ï¿½1.00              ï¿½18.87

                      Fe          4.11     3*35   4.87      4.00    97.3     3.12     93.1       4.67     96.0
                                  ï¿½0. 1    ï¿½0. 1 ï¿½0.12     ï¿½0.12            ï¿½0.11              ï¿½0.15

                        Mn        555      375    470       550     99.1      287     76.5       348      74.0
                      (99/9)      ï¿½19      ï¿½20    ï¿½12     ï¿½15.38           ï¿½17.90              ï¿½15.17

                        Ni        44.1     32     44.1      40      90.3     29       91.6        39      89.3
                      (gg/g)      ï¿½3       ï¿½3     ï¿½2    1 ï¿½1.05   1         ï¿½1.38            1 ï¿½1.24
                        Zn        438      138    824       416   1 94.9      116     84.2       796      06.6
                      (gg/g)   11 ï¿½12  _I  ï¿½6     ï¿½22    1 ï¿½3.08            ï¿½1.40              ï¿½9.68

                     *BR    NIST-SRM #2704 - Buffalo River Sediment
                     *ES   NIST SRM #1646 - Estuarine Sediment
                    *PAC= National Research Council of Canada PACS-1 - Marine Sediment























                                                                  34
                   Fffabe
                        the  er



                      Metals










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                                                         37








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                         1328.




                                                                 38








              Sieling, F.W., 1958, Low      salinity and unusual biological conditions noted in
                  Chincoteague Bay: Maryland Tidewater News, vol. 14, no. 4, p. 15-16.

                            __ , 1959, Chemical and physical data, Chincoteague Bay area, June
                  1953- December, 1956: Maryland Dept. of Research and Education, Univ. of Md.
                  Chesapeake Biological Lab., Solomons, Md., reference 57-25, p. 93.


                               1960,, The resources of Worcester County coastal waters: Maryland
                  Dept. of Research and Education, 'Univ. of Md. Chesapeake Biological Lab.,
                  Solomons, Md., reference 60-27.

              Sinex, S.A., and Helz, G.R., 1981, Regional geochernistry of trace elements in
                  Chesapeake Bay sediments: Environ. Geol., vol.3, p. 315-323.

              Slaughter, T. H., 1973, Regulatory aspects relative to coastal management problems,
                  Ocean City, Maryland's Atlantic coast beach: Shore and Beach, vol. 41, p. 5-11.

              Sommer, S.E., and Pyzik, A.J., 1974, Geochemistry of middle Chesapeake Bay
                  sediments from Upper Cretaceous to present: Chesapeake Sel., vol. 15, p. 39-44.

              STSC, Inc., 1989, STATGRAPHICS, Version 4.0: Users Manual.

              Taylor, S.&, 1964, The abundance of chemical elements in the continental crusts- a
                  new table: Geochim. Cosmochim. Acta, vol. 28, p..283-294.

              Toscano, M.A., 1992, Record of Oxygen Isotope Stage 5 on the Maryland inner shelf
                  Atlantic Coastal Plain- A post-transgressive-highstand regime, in Wehmiller, J.F.
                  and Fletcher, C.H. (eds.), Quaternary Coasts of the United States: Lacustrine and
                  Marine Systems: Society of Economic Paleontologists and Mineralogists (SEPM)
                  Special Publication No. 48, p. 89-99.

              Toscano, M.A., Kerhin, R.T., York, L. L., Cronin, T. M., and Williams, S. J.,
                  1989, Quaternary stratigraphy of the inner continental shelf of Maryland: Maryland
                  Geological Survey Report of Investigation 50, 117 pp.

              Toscano, M.A. and York, L. L., 1992, Quaternary stratigraphy and sea-level history
                  of the U.S. middle Atlantic Coastal Plain: Quaternary Sci. Rev., vol. 11, p. 301-
                  328.


              Trefry, J.H., and Presley, B.J., 1976, Heavy metals in sediments from San Antonio








                         Bay and the northwest Gulf of Mexico: Environ. Geol. vol. 1, p. 283-294.

                      Truitt, R.V., 1968, High winds--high tides: a chronicle of Maryland's coastal
                         hurricanes: Univ. of Maryland, Nat. Res. Inst., Ed. Ser. No. 77, 35 pp.

                      University of Md. (UM), and Coastal Environmental Services, Inc. (CESI), 1993,
                         Maryland's coastal bays: an assessment of aquatic ecosystems, pollutant loadings,
                         and management options: submitted to Maryland Dept. of - the Environment,
                         Chesapeake Bay and Special Projects Branch, Baltimore, Md.

                      U.S. Army Corps of Engineers, 1962, The March 1962 storm along the coast of
                         Maryland: Report of District activities during and immediately following the storm,
                         Baltimore District, Baltimore, Maryland, 21 pp.

                      Williams, S.C., Simpson, H.J., Olsen, C.R., and Bopp, R.F., 1978, Sources of heavy
                         metals in sediments of the Hudson River estuary: Marine Chem., vol. 6, p. 195-
                         213.


                      Van Loon, J.C., 1980, Analytical Atomic Absorption Spectroscopy: Selected
                         Methods: Academic Press, New York, 337 pp.

                      Villa, 0., Jr., and Johnson, P.G., 1974, Distribution of metals in Baltimore Harbor
                         sediments: Annapolis Field Office, Tech. Report 59, U.S. Environmental Protection
                         Agency (EPA-903/9-74-012).




















                                                                  40










































































                                                               41




































                                                                                                               I











                                                          Appendix I
                                   Location data for coring sites and selected seismic surveys .



















                                                               42








              Table VM. Coordinates (latitude and longitude) of time fixes for seismic records
              presented in Figures 2 and 3. Coordinates are based on 1927 North American datum.


                TRACK'       FIX     DATE       TIME             LATITUDE                LONGITUDE               COMMENTS
                LINE                                       DD MM           SS.S       DD MM SS.S

                 RUN 3          32   May 4      1429       38      22       37.7      75       6      9.8
                                      1992

                                33              1431       38      22       37.8      75       6      17.8

                                34              1433       38      22       38.3      75       6      27.1

                                35              1435       38      22       38.9      75       6      34.9    Core station 9

                                36              1437       38      22       38.8      75       6      44.0

                                37              1439       38      22       39.8      75       6      52.9

                                38              1441       39      22       40.2      75       7      1.1

                                39              1443       38      22       42.8      75       7      9.7

                             end                1445       38      22       39.3      75       7      18.6    EOL;
                                                                                                              Cedar Island

                RUN 8           1    May 5      1157       38      26       14.9      75       5      1.8     SOL; Corn
                                      1992                                                                    Hammock

                                2               1119       38      26       15.6      75       4      57.7    west to east;
                                                                                                               A,. = 85-

                                3               1201       39      26       15.4      75       4      51.6

                                4               1203       38      26       15.5      75       4      51.5

                                5               1205       38      26       14.9      75       4      37.0

                                6               1207       38      26       16.2      75       4      29.2

                                7               1209       38      26       16.9      75       4      20.2
                                8               1211       38      26       17.9      75 1     4      12.8
                                9               1212       38      26       18.3      75       4      9.0     EOL; Montego
                                                                                                              Bay Trailer Park



















                                                                        43








                        Table IX.         Geographical coordinates and general information for sampling stations.


                          STATION             LATITUDE                LONGITUDE            LENGTH          ATER           COMMENTS
                                                                                              (CM) TDE JH
                                          DD     MM       SS.S     DD     @M        SS.S

                                1         38      25      23.3     75       5       41.7      -75          2.13

                                2         38      25      23.6     75       5       13.0      -60          2.29


                                3         38      25      23.6     75       4       52.5      SURF         1.98


                                4         38      26      28.2     75       4       33.8      -68          3.05      MONTEGO BAY


                                5         38      24      2.7      75       5       6.5       SURF         2.44


                                6         38      24      5.4      75       5       13.4      -85          2.44

                                7         38      23      47.3     75       7       46.5      -88.5        1.83      ST. MARTIN RIVER


                                8         38      23      37.7     75       8       36.6      SU RF        2.44      DEAD-END
                                                                                                                     CANAL,OCEAN
                                                                                                                     PINES


                                9         38      22      41.3     75       6       43.3      -76          1.98


                                10        38      22      42.4     75       5       59.2      -76          2.13


                                11        38      22      43.6     75       5       9.3       -41          2.13


                                12        38      21      34.0     75       7       43.5      -89          2.44      TURVILLE CREEK

                                13        38      25      26.2     75       4       19.6      -73          1.07

                                14        38      20      19.6     75       5       46.5      -130         1.07






























                                                                                    44




























                                              Appendix 11

          Lithologic logs and xeroradiographs for sediment cores collected in Isle of Wight and
          Assawoman Bays. Coordinates and descriptions for the surficial samples are also
          included. Refer to Table IX and Figure 5 for station locations.       Sediment color
          descriptions are referenced to the GSA Rock-Color Chart which is based on the Munsell
          system of color identification (Goddard et aL, 1948).



















                                                    45










                  STATION 1


                  DEPTH         DESCRIPTION
                    (cm)

                    0-2         Greenish-black (5GY 2/1) soft, mud; slightly gritty texture.

                  10-14         Slightly lighter, greenish black (5GY 2/1), soft mud, no visible banding but
                                laminae seen in xeroradiograph.

                  14-20         Greenish black (5GY 2/1) mud, slightly firmer and more gritty than above
                                section; gradually lightens to greenish grey (5GY 4/1), decrease in silt
                                downcore.


                  20-75         Uniform, firm cohesive, smooth mud, dark greenish grey (5GY 4/1), slight
                                mottling, group of mud snails at 40-42 cm, few shell fragments throughout
                                bottom.





































                                                              46






                                             Station I
                                             Greys Creek


               cm
                 0                                                       - ------------------- ---


                                                                       65
                                          35
                                                                                     M
                                                                                     WE

                        . ...... . . . . .

                 5
                                                                                        @,M
                                                          -XX*
                                                    . .. .........
                             OEM.                                      70
                            ............
                                          40
                                                                                     M


                                ......                        i*K
               10
                                                                                      ..........




                                                                       75
                                          4b

                                   %
                 5



                       1Q,                               ... .... ..
                                          50

                                                      Rl@
               20
                                "X x
                                                      ::.:r ->Mx@
                                                        Rik..
                                                          MR


                                          55
                               iki
                                 N
                         :`* . ..........
               25


                                                       OM iKIN


                                          60


               30               N









                                                     47










                   STATION 2


                   DEPTH         DESCRIPTION
                     (cm)

                     0-.23       Dark greenish grey, silty cohesive mud, silt decreases slightly down core,
                                 somewhat mottled appearance with darker band at 14-16 cm; snails at
                                 surface, plant material - rhizomes - found'in upper 10 cm.

                   23-30         Lighter greenish grey mud, stiffer than overlaying mud, very little silt, no
                                 odor.


                   30-46         Greenish grey, slightly darker silty mud, silt. increases down core; mud snail
                                 at 44 cm.


                   46-55         Mottled mixture of silty mud and peat material, large pocket of peat at 46
                                 to 50 cm.


                   55-60         Dark brown black gritty mud, peat mixed with large piece of wood.



                   STATION 3


                   DEPTH         DESCRIPTION


                   Surface       Bottom too hard for *gravity corer; collected a grab sample: tan to brown
                                 medium to fine sand, some silt.


















                                                                48






                                                   Station 2
                                               Assawoman Bay


                          0-
                                                                                       daft,
                                                                      30



                          5

                                                                      35



                         10


                                                                         0




                         15
                                             F
                                    Tar-,



                          0


                                                                       50                           -kw



                         25


                                                                       53



                         30


                                          I'ZN;
                                                                       60
                                                              49










                  STATION 4


                  DEPTH         DESCRIPTION
                    (cm)

                    0-17        Dark green grey (5Y 3/2), firm mud, thin      I cm floe layer -oxidized to
                                brown color, plant material - rhizomes.

                  17-40         Olive grey mud, becoming more firm (less water content) and siltier down
                                core, fine mica flakes present; burrow filled with darker mud extends from
                                17 to 20 cm; very dense clay ball at bottom of burrow (;5 cm), very visible
                                in xeroradiograph; layer of shells, bivalve fragments at 34 to 35 cm.

                  40-67         Color change to grey sediment, slightly softer, less silt, more cohesive, no
                                mica, sediment becomes very smooth, even texture to bottom of core,
                                occasional shell fragment; pocket of shell hash at 42 cm; several gastropods
                                (mud snails) at 60 to 64 cm.

                  STATION 5


                  DEPTH         DESCRIPTION


                  Surface       Bottom too hard for corer, collected grab sample: brown muddy sand.





















                                                              50






                                                                                            Station 4
                                                             Assawornan Bay/Montego Bay



                              cm
                                                                                        3                                                          50





                                 5                                                      35
                                                                                                                                                   55




                                 0                                                      40


                                                                                                                                                   60


                              15                                                        45


                                                                                                                                                   65

                             20
                                                                                            0

                                                                   i- ILA








                             25
                                                                                        55
                                                        'I-,o T




                             30                                                         60



                                                                                                           51










                 STATION 6


                 DEPTH        DESCRIPTION
                   (cm)

                   0-28       Greenish black (5GY 2/1), cohesive gritty mud, gradually lightens with
                              depth.

                 28-45        Somewhat abrupt change to dark greenish grey or olive grey (5Y 4/1 or
                              5GY 4/1) mud.

                 45-62        Medium grey, sandy mud with pockets of clay, shell fragments and pockets
                              of sandier, very firm mud.

                 62-80        Medium dark grey (N4) mud, little or no silt, homogeneous, very dense,
                              smooth, firm mud, no HS odor.
































                                                          52







                                                                         Station 6
                                                                  Assawoman Bay



                       cm
                                                                     30



                          5                                          35                                            65


                                                                                                                                         'MOM'




                         10
                                                                     40                                            70
                                                                                                                                         OR


                                                                                               -
                                                                                               SL
                                                                                                L'.


                        15                                           45
                                                                                                                   75




                       20                                               0

                                                                                                                   so




                       25                                            55





                       30                                            6






                                                                                    53










                  STATION 7


                  DEPTH         DESCRIPTION
                   (cm)

                   0-10         Dark olive grey (5Y 2/1), somewhat watery, slightly silty mud, slight H2S
                                odor.


                  10-87         Light olive grey (5Y 4/1); very little color change down rest of core, mud
                                becomes more firm - less water; xeroradiograph shows mud is bioturbated
                                but distinct laminae is evident at 30, 43, & 82 cm (not seen visually), few
                                shell fragments scattered throughout, thin shell layer at 46-48 cm.



                  STATION 8


                  DEPTH         DESCRIPTION



                  Surface       Bottom too hard for gravity corer, collected surficial sample: Dark brown
                                stiff sand mud, abundant leaf and woody material.























                                                              54







                                                                              Station 7
                                                                        St. Martin River




                         cm                                                                    . . . . . . . . . . . . . .


                                                                          30
                                                                                                                           60



                            5

                                                                          35

                                                                                                 Nv
                                                                                                                           65



                          10

                                                                          40

                                                                                                                           70



                            5                   A

                                                                             5

                                                                                                                           7


                                                                                                                                                        jv-
                         20

                                                            j..           50

                                                                                                                           so
                                            A-E
                                                                                                      uK.


                         25


                                                                            5









                                                                                          55










                   STATION 9


                   DEPTH         DESCRIPTION
                    (cm)

                    0-26         Very thin (2 mm) floc layer on top of olive black (5Y 2/1), silty mud,
                                 somewhat watery, silt decreases downcore, no visible structures.

                   26-48         Very subtle change in color to olive grey mud, becomes firmer down core.

                   48-76         Mottled olive grey (5Y 4/1) to dark greenish grey (5GY 4/1), cohesive mud,
                                 very firm; large relic burrows filled with less firm (more watery) mud; voids
                                 (gas pockets?) which may have been worm burrows; few shell fragments,
                                 disarticulated bivalves at 68 cm, live worms (Polychaetes) throughout core.































                                                               56






                                                            Station 9
                                                      Isle of Wight Bay


                   cm
                     0
                                                                                               65

                                                         35


                     5
                                                                                               70


                                                           0
                                                                       " En'n, ,

                    10                                                    EMOURN&I'l  A
                                                                        A
                                                                                               75

                                                                      O'M
                                                         45


                    15


                                                         50



                   20                                                Vp



                                                         55


                                   %Z-
                     5


                                                         60



                   30


                                                         65





                                                                      57










                   STATION 10


                   DEPTH        DESCRIPTION
                    (cm)

                    0-10        Thin (0.5 cm) oxidized brown mud layer on top of greyish black (N2),
                                slightly gritty, cohesive mud, gradually lightens to greenish black (5GY 2/1)
                                mud.


                   10-34        Dark greenish grey (5GY 4/1) mud, silt increase with depth; subtle mottling
                                between 14-34 cm, abundant worm burrows which appear as voids in split

                                core.


                   34-76        Dark greenish-grey, cohesive, firm mud; layer distinct in xeroradiograph but
                                not visually visible, large watery pocket of mud at 64-66 cm; few shell
                                fragments throughout core.





























                                                               58






                                                                      Station 10
                                                                 Isle of Wight Bay


                       cm
                          0                                          30                                            60




                          5
                                                                     35
                                                                                                                   65





                       10
                                                                     40
                                                                                                                   70





                       15
                                                                     45
                                                                                                                   75




                       20
                                                'wn
                                                                     50

                                            -Ap




                                                                                          G
                       25

                                       24@
                                                                     55
                                                                                        L---K





                       30

                                                                     60





                                                                                      59










                  STATION 11


                  DEPTH          DESCRIPTION
                   (cm)

                   0-37          Dark greenish-grey to brownish-grey, dry, silty mud; worm burrows
                                 throughout (visible in x-ray) suggesting sediment is fairly bioturbated; live
                                 worms (polychaetes) common; very subtle (faint) laminae at 10, 18 and 36
                                 cm. Sediments become slightly lighter and more dense down core. Mica
                                 flakes are abundant. Shell fragments at 14-15 cm. Strong H2S odor when
                                 first opened, but dissipated quickly; strongest H2S odor at 26-29 cm. Mud
                                 snail (Na@sarius) at 38 cm.
































                                                               60






                                                 Station.1 1
                                   Isle of Wight Bay/ Reedy Pt.


                       cm








                                                                                   ---- -- ---- .. ....
                                                                                    Mml







                                                                                  --- - -- -- -------------



                                               . . . . . . . . . . . . .



                                   @ OWN                                             ......



                                             . . . . . . . . . . . .-"-'

                                          M XX

                                                      /MAz
                                        go

                                                                                                   Xx


                                                                                 ...... .......... ............. -1 .........


                                                  -K,X,
                                       4g







                        20







                                    x;.4,






                                      ........ .......
                        25-:

                                                     . . . . . .. . . . . . . .
                                       .................... Om

                                                           61
                                                                         ;all










                 STATION 12


                 DEPTH        DESCRIPTION
                   (cm)

                  0-6         Mottled greyish black (N2), to olive black (5Y 2/1), somewhat watery, gritty
                              mud. Sediments gradually lighten down core to uniform olive grey (5Y
                              4/1). Slight H2S odor detected when opened.

                   4-14       Radiograph suggested presence of gas in mud, darker sediments, and small
                              burrows compared to what is seen between 20-30 cm.

                 20-25        Dryer and firmer than above intervals, no distinguishing features except for
                              worm burrows which show up as voids.


                 34-36        Plant material.





































                                                          62







               Station 12
               Turville Creek



     cm
      0        2



      5         30       60

                  I



                35       65
      10


      15        40       70


               4         75
      20



                50       80
     2              A

               5         85





                  63










                  STATION 13


                  DEPTH          DESCRIPTION
                    (cm)

                    0-4          Light tan sand; layer was lost during core processing.

                    4-13         Medium to fine sorted, light olive grey (5Y 7/1) sand (lighter than 5Y 6/1).

                  12-16          Mottled interface where sand becomes darker, olive grey (5Y 4/1).

                  16-36          Mottled light olive grey (5Y 6/1) to olive grey (5Y 4/1) fine sand.

                  36-42          Shell layer, pockets of olive black (5Y 2/1), muddy sand and shell
                                 fragments.

                  42-69          Mottled medium Nght grey (N6) to medium grey (N5) fine sand, very small
                                 inclusion of peat (approximately 1-2 mm) between 54-60 cm, below 60 cm -
                                 visible small laminae, alternating light & medium grey fine sand.

























                                                              64






                                                                                                     Station 13
                                                                    Assawoman Bay/ Horse Island


                                cm




                                                                                                     30

                                                                                                                                                                          60
                                    5
                                                                                                                                                                                                                              iR"
                                                                                                                                              T
                                                                                                                                           md
                                                                                                     35

                                                                                                                                                                         65
                                    0



                                                                                                         0


                                15



                                                                                                         5


                                20



                                                                                                     50
                                                                                                                                             h1F     n



                                25



                                                                                                                                                  4@f@


                                                                                                     55








                                                                                                                          65










                 STATION 14


                  DEPTH         DESCRIPTION
                   (cm)

                    0-50        Mottled olive grey (5Y 4/1) and greenish black (5GY 2/1), muddy sand,
                                very firm, compact mica flakes visible, decrease in sand down core, light
                                layer (5Y 4/1) of muddy silt at 25 cm, darker greyish black (N2), silty mud
                                above and below layer.

                   50-68        Greenish black (5G 2/1), silty mud, very compact, dry, firm, mica appears
                                to decrease downcore.


                   68-75        Greenish black (5G 2/1) to olive grey (5Y 4/1).mud with pockets of peat -
                                greyish brown (5YR 3/2) to moderate brown (5YR 3/4) in color, amount of
                                peat gradually increases down core.

                   75-88        Predominately peaty material inter-bedded with thin mud, laminae at 82-84

                                cm.


                   88-103       Brownish black (5YR 2/1) mud, gradual decrease in peat.

                  103-120       Banded inter-bedded peat and mud alternating between brownish black to
                                light olive grey mud.

                  117-120       Light olive grey (5Y 6/1) mud interlaced with vertical peat stringers which
                                may be remnants of plant roots - rhizomes.

                  120-128       Predominately olive black (5Y 2/1) mud with pockets of peat.















                                                             66






                                             Station 14
                               Isle of Wight Bay/ Horn Island
                                                (Top 76 cm)





              cm
                0                                                          50
                                                                                           im
                                                                                              TV


                                            30


                5                                                          55


                                                                                      ZM
                                            35

                                                                           60
              10
                                                           W-
                                      3-


                                            40

                                                                   41
              15              @OW                                          65
                      "NEW
                        _Vd                                M,



                                            45
              20
                                                                           70




                                                                                           IN
                                            50
              25
                                                                           75










                                                       67







                                                                Station 14
                                                Isle of Wight Bay/ Horn Island
                                                                  (Boftom 60 cm)




                          cm
                                                                                                    110
                          75                                     95




                                                  a,

                                                                                       ul           115
                                                              100
                          so

                                                                                                                    @`04








                                                              105
                          85                                                                                        @,m IN,
                                                                                                                  17
                                                                                                                 -
                                                                                                                    2       pu
                                                                                                                 1, -T      'ic, @4
                                                                                                                            40
                                                                                                                             6A@@


                                                                                                   12
                                                              110
                          90



                                                                           N&

                                                                           aq P.
                                                                           -0.6
                                                              115

                          95













                                                                            68























  4
















                                             Appendix III
                        Textural and geochemical data for core sediment samples.





















                                                   69








                        Table X.          Textural data for sediment samples taken from cores.


                                                                                                                        Statistical
                                    Sample Interval      Water            Textural Component          Shepard's        Parameters
                          Station          (cm)          content          (percent by weight)           (1954)     (sand fraction only)
                                                Lower                Sand         Silt      Clay        Class.*     Mean           ing
                                                                                                                               Sort
                                                                                                                                   0
                             1        0         4        52.51       2.59       69.48       27.93        cisi
                             1        -10       -14      51.93       6.90       70.91       22.19        cisi
                             1        -20       -24      47.27       39.94      37.87       22.19       SaSiCl       2.92       0.58
                             1        -30       -34      41.26       22.19      51.77       26.05        cisi        3.17       0.58
                             1        -40       44       36.92       22.03      51.27       26.70       SaSiCl       3 .33      0.41
                             1        -50       -53      50.63       2.67       52.48       44.85        cisi        3.33       0.52
                             1        -60       -63      53.17       2.53       54.56       42.91        cisi        2.92       0.88
                             1        -72       -75      52.52       1.50       55.84       42.66        cisi        3.50       0.31
                             2        0         -2       31.21       56.96      30.42       12.62        SiSa        2.75       0.52
                             2        -2        4        30.52       61.99      27.17       10.84        SiSa        2.58       0.55
                             2        4         -6       30.85       69.85      19.85       10.29        SiSa        2.42       0.65
                             2        -6        -8       32.08       66.04      23.37       10.59        SiSa        2.58       0.72
                             2        -8        -10      31.96       62.50      25.83       11.68        SiSa        .2.50      0.62
                             2        -18       -20      26.95       68.60      22.22       9.18         SiSa        2.42       0.65

                             2        -24       -26      51.39       25.84      42.45       31.72       SaSiCl       2.67       0.65
                             2        -32       -34      19.28       65.06      21.88       13.06        SiSa        2.50       0.72
                             2        -40       -42      19.77       78.86      14.78       6.37          Sa         2.42       0.78
                             2        -50       -52      33.98       63.30      25.09       11.61        SiSa        2.25       0.75
                             2        -58       -60      32.69       72.81      16.05       11.14        SiSa        2.17       -0.62
                             3        0         0        18.65       93.40      4.53        2.07          Sa         2.58       0.34
                             4        0         -4       38.65       38.30      46.58       15.11        SaSi        3.25       0.28
                             4        -8        -12      40.04       48.59      36.97       14.44        SiSa        3.08       0.45
                             4        -16       -20      39.60       26.41      57.33       16.27        SaSi        3.08       0.55
                             4        -24       -28      33.57       18.99      64.38       16.63        SaSi        3.33       0.34
                             4        -32       -36      37.73       12.98      68.09       18.93        Cisi        3.25       0.28
                             4        40        44       48.17       3.88       62.13       33.99        Cisi        3.25       0.32
                             4        -50       -54      50.09       0.95       59.90       39.15        Cisi
                             4        -60       -64      45.35       2.01       64.92       33.08        Cisi
                             5        0         0        26.02       74.58      18.10       7.32         Sisa        2.83       0.41
                             6        0         -2       48.86       15.08      60.80       24.13        Cisi        3.33       0.30
                             6        -4        -6       45.76       19.71      57.10       23.19        Cisi        3.42       0.24
                             6        -12       -14      44.19       21.40      57.62       20.98       SaSiCl       3.25       0.28
                             6        -24       -26      45.96       22.85      49.35       27.80       SaSiCl       3.25       0.35
                             6        -34       -36      45.13       33.51      41.78       24.71       SaSiCl       3.00       0.52
                             6        -46       -48      28.00       28.16      51.83       20.01       SaSicl       2.83       0.52
                             6        -58       -60      28.15       46.07      37.63       16.30        SiSa        3.00       0.52
                             6        -78       -80      46.57       8.26       50.14 1 41.60            Cisi        3.17


                                                                                   70











                                                                                                                   Statistical
                            Sample Interval        Water            Textural Component           Shepard's         Parameters
                 Station          (cm)             content          (percent by weight)             (1954)    (sand fraction only)
                                         ower                  Sand        Silt       Clay          Class.*     Mean      Sorting
                           105T                                                                I                   (t         0
                    7         0          -2        61.13       0.69        56.07      43.25         Clsi
                    7         -4         -6        58.58       1.78        59.24      38.97         Clsi
                    7         -8         -10       55.43       3.57        58.80.     37.62         Clsi
                    7         -12        -14       50.04       2.17        58.53      39.30         Clsi
                    7         -24        -26       46.48       1.31        58.89      39.79         clsi
                    7         -36        -38       48.83       1.93        63-40      34.67         Clsi
                    7         -48        -50       53.01       1.00        57-02      41.98         Clsi
                    7         -60        -62       56.58       0.57        50.15      49.28         Clsi
                    7         -72        -74       59.39       0.73        44.12      55.15         sicl
                    7         -84        -86       56.44       0.73        48.04      51.23         sicl
                    8         0          0         47.43       16.81       46.10      37.19         Cisi         2.67       0.65
                    9         0          -2        47.22       5.69        70.88      23.43         ClSi         3.50       0.24_
                    9         -6         -8        46.31       5.82        69.58      24.61         ClSi         3.50       0.28
                    9         -14        -16       40.42       7.10        70.08      22.82         Clsi         3.50       0.28
                    9         -24        -26       42.40       6.88        66.83      26.29         Clsi         3.42       0.38
                    9         -34        -36       42.52       7.91        66.17      25.92         clsi         3.50       0.2
                    9         -50        -52       32.49       15.07       68.10      16.84         ClSi         3.42       0.41
                    9         -72        -74       39.65       2.05        72-32      25.62         Clsi         3.42       0.41
                    10        0          -3        44.14       14.21       60-04      25.76         Pisi         3.50       0.28
                    10        -5         -8        46.52       18.13       56.09      25.79         Clsi         3.33       0.34
                    10        -14        -17       36.40       35.60       45.97      18.43         SaSi         3.17       0.38
                    10        -27        -30       35.19       44.35       36-44      19.20         SiSa         3.25       0.28
                    10        -45        -48       35.82       38.16       44-24      17.61         SaSi         3.25       0.28-
                    10        -57        -60       41.12       24.19       52.31      23.49         SaSiCl       3.33       0.34
                    10        -72        -75       43.87       13.43       56-39      30.19         Clsi         3.42       0.41
                    I 1       0          -3        31.34       63.40       25-68      10.93         SiSa         3.17       0.28
                    11        .9         -12       27.77       60.03       26.40      13.57         SiSa         3.25       0.28
                    11        -17        -20       24-33       72.94       17.14      9.91          SiSa         3.17       0.29
                    11        -26        -29       29-20       70.24       20-31      9.45          SiSa         3.25       0.28
                    11        -34        -37       25.04       69.04       21-20      9.76          _SiSa        3.00       0.28
                    12        0          -2                         Sample not analyzed for textural parameters
                    12        -6         -8        56-88       3.90        64.82      31.29         Clsi
                    12        -14        -16       56.39       5.71        67.70      26.59         Clsi
                    12        -24        -26       51.71       3.46        66.35      30.19         Clsi
                    12        -34        -36       56-35       2.55        63.07      34.39         Clsi
                    12        -50        -52       54-02       3.63        62.95      33.42         Clsi         3.50       0.24
                    12        -68        -70       52.49       0.60        62.74      36.65         Clsi
                    12        -84        -86       56.50       0.45        57.58      41.97         Clsi
                    13        -4         -6        7.98        100.00      0.00       0.000           Sa



                                                                             71












                                                                                                                        Statistical
                                      Sample Interval     Water            Textural Component          Shepard's        Parameters
                          Station           (cm)          content          (percent by weight)          (1954)     (sand fraction only)
                                                 Lower                Sand        Silt   I   Clay       Class.*                   rting
                                                                                                                        (b         M

                            13        -14        -16      16.54       99-88      0.12        0.001         Sa        2.42        0.41
                            13        -36        -40      16.04       94.17      3.31        5.83          Sa        233         0.52
                            13        -48        -50      17.45       98.27      1.69        0.04          Sa        2.67        0.41
                            -13       -64        -66      18.09       97.07      2.93        0.001         Sa        2.75        0.28
                            14         0         -3       22.94       84.18      12.56       3.26          Sa        3.08        0.38
                            14        -22        -25      32.53       71.16      19.49       9.35         Sisa       3.08        0.18
                            14        -27        .-30     22.50       92.64      6.26        1.10          Sa        3.00        0.24
                            14        -40        -43      25.48       84.63,     11.00       4.38          Sa        3.25        0.28
                            14        -57        -60      41.50       20.18      50.66       29.16      Sasicl       3.2         0.28
                            14        -75        -78      67.88       2.49       45.63       51.88        Sict
                            14        -80        -83      78.93       12.43  1   38.53   1   49.05        Sicl
                            14        -84        -86          Sample predominately peat; not analyzed for textural parameters
                            14        -94        -97      74.50       0.24       38.57       61.19        Sicl
                            14        -101       -103     80.89       1.64       44.35       54.01        SiCl
                            14        -105       -106            Sample entirely peat; not analyzed for textural parameters
                                      -107       -110     79.30       0.40       49.54       50.06        Sicl
                            14        -117       -120     69.10       0.34       55.55       44.11        ClSi
                            14        -125 L_jL27         54.09       0.17       50.08       49.76        Clsi

                        *Key for sediment classification in Table XI, based on Shepard's (1954) nomenclature:
                                      Sa = SAND                                  Si = SILT
                                      Cl = CLAY                                  SaSi = SANDY SILT
                                      SiSa       SILTY SAND                      ClSa = CLAYEY SAND
                                      SaCl       SANDY CLAY                      SICI = SILTY CLAY
                                      CISI       CLAYEY SILT                     SaSiCl      SAND-SILT-CLAY


















                                                                                   72
                         F
                            tab
                         1








            Table X1.       Chemical data for sediment samples.

                               Swnple Interval         Carbon         Nitrogen         Sulfur      Monosulfide
              Station 4             (cm)                       . I                I
                             Upper       Lower                           Percent by weight
                  1            0           -4           2.63            0.22            1.04           0.034
                  1            -10         -14          2.93            0.25            1.43           0.027
                  1            -20         -24          2.09            0.17            1.32           0.004
                  1            -30         -34          1.61            0.00            1.27           0.006
                  1            -40         -44          1.54            0.00            1.16           0.004
                  1                        -53          1.62            0.19            1.71           0.003
                  1            -60         -63          1.74            0.13            1.47           0.005
                  1            -72         -75          2.41            0.21            1.82           0.006
                  2            0           -2           0.90            0.15            0.25
                  2            -2          -4           0.87            0.15            0.27
                  2            -4          -6           0.91            0.13            0.32
                  2            -6          -8           0.00            0.00            0.00
                  2            -8          -10          0.97            0.12            0.35
                  2            -18         -20          0.81            0.11            0.28
                  2            -24         -26          1.69            0.18            1.20
                  2            -32         -34          0.45            0.04            0.26
                  2            -40         -42          0.44            0.10            0.26
                  2            -50         -52          1.38            0.14            0.69
                  2            -58         -60          3.96            0.17            0.92
                  3            0           0            1.85            0.18            0.09
                  4            0           -4           1.70            0.17            0.52
                  4            -8          -12          1.50            0.15            0.88
                  4            -16         -20          1.45            0.13            1.02
                  4            -24         -28          1.22            0.12            0.77
                  4            -32         -36          1.45            0.13            1.08
                  4            -40         -44          1.34            .0.17           1.23
                  4            -50         -54          1.64            0.15            1.52
                               -60         -64          1.71            0.18            1.65
                  5            0           0            0.74            0.00            0.22










                                                              73









                                        Sample Interval         Carbon         Nitrogen          Sulfur      Monosulfide
                       Station               (cm)                         T                I
                                     Upper        Lower                           Percent by weight
                           6            0           -2           1.99            0.20            0.61
                           6            -4          -6           1.77            0.22            0.74
                           6            -12         -14          1.76            0.17            0.95
                           6            -24         -26          1.68            0.19            0.95
                           6            -34         -36          1.39            0.17            0.83
                           6            -46         -48          0.72            0.07            0.44
                           6            -58         -60          0.60            0.12            0.47
                           6            -78         -80          1.29            0.13            1.11
                           7            0           -2           3.62            0.31            1.48
                           7            -4          -6           3.27            0.28            1.67
                           7            -8          -10          2.76            0.29            1.50
                           7            -12         -14          1.58            0.18            1.03
                           7            -24         -26          1.55            0.20            1.21
                           7            -36         -38          0.90            0.00            0.87
                           7            -48         -50          1.41            0.17            1.33
                           7            -60         -62          1.66            0.20            1.43
                           7            -72         -74          2.49            0.28            1.68
                           7            -84         -86          2.70            0..25           2.00
                           8            0           0            3.15            0.24            0.89
                           9            0           -2           1.66            0.17            0.62
                           9            -6          -8           1.63            0.18            0.77

                           9            -14         -16          1.50            0.16            0.85
                           9            -24         -26          2.00            0.20            1.34
                           9            -34         -36          1.21            0.14            0.90
                           9            -50         -52          0.71            0.14            0.71
                           9            -72         -74          0.67            0.17            0.65
                           10           0           -3           2.03            0.20            0.83           0.059
                           10           -5          -8           2.05            0.18            1.03           0.087
                           10           -14         -17          1.38            0.14            0.75           0.011
                           10           -27         -30          1.27            0.13            1.01           0.002
                           10           -45         -48          1.18            0.17            0.80           0.001
                           10           -57         -60          1.36            0.12            1.08           0.004
                           10           -72         -75          1.43            0.15            1.25           0.003
                           11           0           -3           0.90            0.10            0.24
                           11           -9          -12          0.72            0.09            0.59



                                                                       74








                               Sample Interval         Carbon        Nitrogen           Sulfur     Monosulfide
              Station               (cm)                                          I               I
                            Uppe-r7 Lower                               Percent by weight
                  11           -17         -20          0.90            0.08            0.36
                  11           -26         -29          0.96            0.11            0.44
                  1 1          -34         -37          0.63            0.08            0.30
                  12           0      1    -2           3.65            0.32            1.13
                  12           -6          -8           3.46            0.29            0.13
                  12           -14         -16          3.52            0.29            1.48
                  12           -24         -26          3.00            0.30            1.34
                  12           -34         -36          3.46            0.27            1.72
                  12           -50         -52          3.35            0.27            1.30
                  12           -68         -70          2.61            0.28            1.32
                  12           -84         -86          3.41            0.31            1.90
                  13           -4          -6           0.25            0.04            0.04
                  13           -14         -16          0.19            0.00            0.02
                  13           -36         -40          0.32            0.07            0.11
                  13           -48         -50          0.02            0.00            0.09
                  13           -64         -66          0.08            0.00            0.05
                  14           0           -3           0.61            0.08            0.17
                  14           -22         -25          1.14            0.13            0.55
                  14           -27         -30          0.27            0.00            0.15
                  14           -40         -43          0.83            0.08            0.26
                  14           -57         -60          2.49            0.17            1.07
                  14           -75         -78          9.58            0.71            1.87
                  14           -80         -83          16.79           0.94            2.44
                  14           -84         -86          15.54           0.79            2.30
                  14           -94         -97          11.68           0.77            3.00
                  14           -101        -103         20.22           1.21            3.69
                  14           -105        -106         30.01           1.39            5.28
                  14           -107        -110         17.61           1.04            2.51
                  14           -117        -120         8.52            0.46            1.43
            @-l -4             -125   1    -127         3.91            0.28            2.82




                                                              75








                       Table X1 (cont.). Chemical data for sediment samples.


                                      Sample Interval                                 Metal Concentrations
                                            (cm)
                         Station     Upper       Lower          Cr            Cu                      Mri                          Zn
                                                                            ug/g)         Fe                         Ni
                                                              (119/9)       (             (0/0)      (ug/9)        (ug/g)        (ug/g)
                            1           0           -4        72.66         15.67         2.80       315.48        26.33         101.36
                            1           -10         -14       75.66         13.66         3.13       328.70        26.32         99.80
                            1           -20         -24       49.94         5.65          2.21       199.24        15.61         40.67
                            1           -30         -34       69.86         7.46          2.90       31741         22.75         50.87
                            1           -40         -44       67.35         7.46          2.77       303.72        22.63         50.414
                            1           -50         -53       94.89         9.04          3.91       430.59        28.85         70.36
                            1           -60         -63       95.70         9.44          4.04       468.70        29.60         71.41
                            1           -72         -75       89.72         10.64         3.90       382'.80       29.24         68.99
                            2           0           -2        29.13         6.20          1.09       116.69        10.95         37.16
                            2           -2          -4        31.57         5.85,         1.18       140.80        9.97          40.81
                            2           -4          -6        31.29         6.25          1.19       127.62        9.51          43.16
                            2           -6          -8        34.94         6.44          1.25       145.42        12.63         43.73
                            2           -8          -10       34.96         6.58          1.32       153.21        11.51         43.07
                            2           -18         -20       28.89         4.98          1.08       113.76        9.60          37.11
                            2           -24         -26       88.48         11.42         3.32       343.73        29.43         69.05
                            2           -32         -34       24.76         3.61          0.90       112.34        9.05          19.80
                            2           -40         -42       24.70         3.37          0.92       120.70        9.44          18.20
                            2           -50         -52       46.25         5.67          1.74       220.27        15.72         35.39
                            2           -58         -60       15.76         1.59          0.78       45.36         2.61          5.41
                            3           0           0         12.74         2.36          0.46       70.89         5.87          16.06
                            4           0           -4        43.41         12.37         1.64       166.41        12.93         54.68
                            4           -8          -12       43.33         6.06          1.70       179.90        16.00         40.76
                            4           -16         -20       54.70         6.35          2.38       277.82        19.54         41.45
                            4           -24         -28       50.30         5.77          2.12       229.65        17.39         36.88
                        L
                            4           -32         -36       62.30         7.18          2.73       282.45        23.38         47.32
                            4           -40         -44       86.04         8.44          3.66       419.27        28.84         65.89
                            4           -50         -54       87.81         8.28          3.94       428.14        27.74         66.36
                            4           -60         -64       80.09         8.34          3.73       383.51        26.02         59.58
                                        0           0         30.63         6.57          1.13       149.90        10.22         33.40 A
                            4                                                    76
                            5









                        Sample Interval                           Metal Concentrations
                              (cm)
             Station Upper        Lower        Cr          Cu        Fe         Nfn         Ni          Zn
                ii                            (ug/g)     (ug/g)      (%)    I (ug/g)        ug/g)      (ug/g)
                6         0          -2       64.79      11.94       2.67      249.60       22.12      83.56
                6         -4         -6       65.68      12.11       2.63      261.67       21.81      80.89
                6         -12        -14      60.99      8.36        2.54      263.41       18.86      .61.72
                6         -24        -26      63.86      7.82        2.58      241.25       18.49      55.45
                6         -34        -36      70.46      8.46        2.89      278.69       23.43      53.81
                6         -46        -48      35.39      4.14        1.38      139.68       11.85      27.11
                6         -58        -60      38.11      4.20        1.60      203.64       12.55      30.47
                6         -78        -80      90.08      8.36        3.91      500.98       26.79      68.49
                7         0          -2       90.80      18.72       3.60      313.33       28.92      128.93
                7         -4         -6       87.73      15.03       3.69      294.78       26.84      105.40
                7         -8         -10      85.99      12.54       3.56      288.81       26.80      86.52
                7         -12        -14      63.31      8.59        2.48      277.00       18.67      61.93
                7         -24        -26      88.29      8.53        3.83      300.80       25.61      65.58
                7         -36        -38      85.62      8.79        3.90      339.49       26.77      63.62
                7         48         -50      92.62      8.68        4.18      385.91       30.59      70.37
                7         -60        -62      103.63     9.87        4.67      391.61       33.62      78.21
                7         -72        -74      107.14     10.19       4.80      422.29       34.52      80.44
                7         -84        -86      106.06     10.17       4.81      416.55       32.95      75.93
                8         0          0        51.02      14.32       1.99      139.30       20.12      55.11
                9         0          -2       62.69      12.49       2.55      242.01       20.75      84.23
                9         -6         -8       66.20      13.25       2.67      250.81       22.39      89.44
                9         -14        -16      59.38      10.39       2.38      211.28       20.85      64.90
                9         -24        -26      84.81      9.65        3.67      305.29       26.67      67.37
                9         -34        -36      64.74      7.66        2.70      274,46       20.88      50.28
                9         -50        -52      51.74      6.19        2.31      234,49       17.96      41.47
                9         -72        -74      64.44      6.52        2.73      309.59       23.50      46.03
                10        0          -3       69.18      17.03       2.77      273,40       24.40      87.18
                10        -5         -8       70.74      15.45       2.88      293.04       22.86      93.49
                10        -14        -17      50.55      10.32       2.08      207.99       17.16      68.14
                10        -27        -30      51.20      7.81        2.20      247.62       17.62      45.23
                10        -45        -49      49.92      5.83        2.06      206.63       16.61      38.19
                10        -57        -60      65.23      7.96        2.71      273.60       21.79      49.19
                10        -72        -75      76.51      8.71        3.21      342.76       24.06      57.95
                11        0          -3       37.16      7.59        1.32      162.93       14.38      44.40



                                                               77









                                 Sarnple Interval                           Metal Concentrations
                                        (cm)
                      Station    upper      Lower         Cr         Cu         Fe         1%1n          Ni          Zn
                                         I          I   (Ug/g)     (Ug/g        N           Ug/g)  I   (Ug/g)      (Ug/9)
                         11        -9        -12        35.27      7.09         1.27      155.21       11.61       44.96
                         11       -17        -20        29.99      5.39         1.16      141.83       11.18       34.48
                         11       -26        -29        36.55      6.68         1.51      204.39       13.43'      33.49
                         11       -34        -37        29.39      4.19         1.20      136.75       10.68       23.48
                         12        0          -2        73.50      17.30        3.07      242.12       24.18       110.10
                         12        -6         -8        72.84      17.30        3.03      256.98       25.72       107.00
                         12       -14        -16        62.81      14.99        2.74      199.26       21.64       63.79
                         12       -24        -26        65.21      7.71         2.75      253.58       20.66       50.21
                         12       -34        -36        76.62      8.66         3.43      289.43       21.49       53.91
                         12       -50        -52        63.71      8.60         2.72      213.67       20.04       41.21
                         12       -68        -70        85.57      9.64         3.65      287.08       26.52       61.32
                         12       -84        -86        86.12      9.43         3.88      287.13       27.19       62.77
                         13        -4         -6        4.07       .0.74        0.15      27.18        5.15        5.58
                         13       -14        -16        4.61       0.96         0.19      38.55        .3.87       4.74
                         13       -36        -40        12.86      1.74         0.53      91.93        5.33        13.40
                         13       -48        -50        7.40       0.52         0.32      36.84        .3.54       7.72
                         13       -64        -66        8.15       0.34         0.30      39.85        8.13        5.92
                         14        0          -3        20.61      3.84         0.80      89.57        8.10        24.60
                         14       -22        -25        53.05      10.19        2.03      208.29       19.25       66.55
                         14       -27        -30        20.07      5.48         0.76      84.78        9.27        25.22
                         14       -40        -43        31.17      5.86         1.16      134.19       11.87       34.39
                         14       -57        -60        70.62      16.37        2.68      276.69       24.70       85.64
                         14       -75        -78        76.73      10.82        2.84      233.06       27.36       55.96
                         14       -80        -83        63.08      10.45        2.14      136.43       25.06       71.74
                         14       -84        -86        60.16      9.16         1.81      135.47       24.12       44.29
                         14       -94        -97        85.25      11.92        3.51      188.70       32.60       79.14
                         14      -101       -103        58.11      9.31         2.51      145.16       [email protected]       48.31
                         14      -105       -106        42.30      12.62        2.41      112.52       24.70       57.79
                         14      -107       -110        46.03      8.27         1.58      104.03       14.51       26.79
                         14      -117       -120        61.06      5.89    1    1.73   1  119.39       17.07       28.46
                         14      -125       -127        107.19     12.42        4.77      2T4.04       42.67       91.26






                                                                        78






















  I
















           Plots of textural and chemical parameters versus depth in core for each sediment core.





















                                                     79








                                                                                            Station 1


                                                                                       0




                                                                                  -10




                                                                                  -20




                                                                                  -30




                                                                                  -40 -




                                                                                  -50




                                                                                  -60




                                                                                  -70




                                                                                  -80
                                                                                       0      20        40        60       so       100
                                                                                                    WATER el.)




                                                                                       0




                                                                                  -10 -




                                                                                  -20




                                                                                  -30




                                                                                  -40




                                                                                  .50




                                                                                  -60




                                                                                  -70




                                                                                  -80
                                                                                       0       20       40        60       so       100


                                                                                             SAND       SILT -, CLAY


                                                                                                      80







                                                                                       Station i


                                          0                                                                           0



                                        -10                                                                        -10


                                        -20                                                                        -20


                                        -30                                                                        -30


                                        -40                                                                        -40

                                        -50                                                                        -50

                                                                                                                   -60
                                        -60


                                                                                                                   -70
                                        -70


                                                                                                                   -80
                                        -80                                                                           0.000      0.010        0.020       0.030        0.040
                                           0.5      1       1.5      2       2.5      3       3.5                          0.005        0.015       0.025        0.035
                                                                   %                                                              MONOSULFIDES (0/*)

                                                   .,CARBON-, SULFUR




                                                                                 0




                                                                             -10




                                                                             -20




                                                                             -30




                                                                             -40




                                                                             -50




                                                                             -60




                                                                             -70




                                                                             -80
                                                                                 0      0.05     0.1     0.15      0.2    0.25     0.3
                                                                                                NITROGEN







                                                                                                                              Station 1


                                                             0                                                                0                                                              0



                                                          -10                                                                 -10                                                       -10



                                                          -20                                                                 -20                                                       -20



                                                          .30 -                                                               -30                                                       .30



                                                          -40                                                                 -40                                                       .40



                                                          -50                                                                 -50                                                       .50



                                                          -60                                                                 .40                                                       .60



                                                          -70                                                                 .70                                                       -70



                                                          .30                                                                 40                                                        .80
                                                             40    50     60    70    90     90    100   110                  4    6     8     10    12     14    16    18                   2      2.5      3       3.5       4       4.5
                                                                        CHROMIUM (p1m)                                                    COPPER (ppm)                                                     IRON (%)















                                                             0                                                                0                                                              0



                                                          -10                                                                 -10                                                       -10



                                                          -20                                                                 .20                                                       -20



                                                          .30                                                                 -30                                                       -30



                                                          -40                                                                 -40                                                       -40

                                                                                                                       Lu


                                                          -50                                                                 -50                                                       .50



                                                          -60                                                                 .60                                                       -60



                                                          -70                                                                 .70                                                       -70



                                                          .80                                                                 .80                                                       40
                                                             150   200   250    300   350   400    450   500                  10     15       20       25       34       35                  30 40    50    60    70   90    90   100 110
                                                                        MANGANESE (p1m)                                                  NICKEL (ppm)                                                      ZINC (ppm)







                                                                                                                                        82

















                                            DEPTH                                                           DEPTH









                0                                                                    >










             00



                                             DEPTH (cm)                                                     DEPTH (cm)





                    z








                                                                                 Station 2


                                        0                                        0




                                        -10                                      -10                                  -10




                                        -20-                                     -20                                  .20


                                   1    -30                                      .30                                  -30

                                   0    -40                                 0    -40                                fu
                                                                                                                    040




                                        .50                                      -50                                  .30




                                        -60 -                                                                         -60


                                        .701. . . . . . . .                      .70                                  -70
                                        10 20 30 40 io 60 70 go go 100           1 2 3 4 5 6 7 8 9 10 11 12             0.5  1    1.5 2    2.5  3   3.5
                                               CHROMIUM (ppm)                           COPPER (ppm)                               IRON













                                        0                                        0                                      0




                                        40                                       -10                                  -10




                                        .20                                      .20                                  .20



                                        -30                                 -9-30                                     -30

                                   ul
                                   0    40                                  0    -40                                w
                                                                                                                    Q -40




                                        .50                                      -30                                  .50




                                        -60                                      -60                                  .60




                                        .70                                      .70                                  -70
                                        0  50 100 150 200 250 300 350 400        0  5   10  15  20  25  30  35          0   10 20  30 40  50 60  70  80
                                              MANGANESE (pprn)                           NICKEL (pFn)                              ZJNC (ppm)







                                                                                       84
















                                                              DEPTH (cm)                                                                                    DEPTH (cm)




















                                                              DEPTH (cm)                                                                                    DEPTH (an)




                 00                u














                                                              DEPTH (cm)                                                                                    DEPTH (cm)








                                                                                                                               z








                                                       Station 4


                                0                                        0




                             -10                                      -10




                             -20                                      -20




                           E -30
                                                                     E-30




                             -40                                      -40




                             -50                                      -50



                             -60-                                     -60-


                             -700    2.0   410  6.0   810 100         -70
                                        WATER (%)                        0   20    40%  60    90   100

                                                                            SAND.*. SILT CLAY



                                0                                        0




                             -10                                      -10




                             -20                                      -20




                           E -30                                      E-30



                             -40                                      -40




                             -50                                      -50



                             -60                                      -60



                             -70                                      -70
                                0.4 0.6 0.81 1.2 1.4 1.6 1.82            0. 11 0. 12 0.13 0.14 0.15 0.16 0.17 0.18 0.19 0.2
                                            %                                   NITROGEN (0/.)

                                     CARBON-*. SULFUR
                                                             86














                                            DEPTH                                                           DEPTH

                                                                    0     C5




                     C5













                     tj





             00



                                            DEPT14                                                          DEPTH (cm)

















                      t9








                                                                                     Station 6


                                           0                                         0                                         0



                                       -10                                           -10                                    -10



                                       -2D                                           .20                                    .20



                                       -30 -                                         .30                                    -30



                                       -40                                           -40-                                   -40



                                                                                                                            .50



                                       -60                                           -60                                    .60



                                       -70                                           .70                                    .70



                                       40  -                                         -W-                                    40

                                       -90 1                                         _90                                    _90
                                           30 40  50  60  70   90  90  100           3 4  5  6  7  8  9 10 11 12 13            1  1.5  2  23   3   3.5  4  4.5
                                                 C14ROMIUM (ppm)                             COPPER (p1m)                                IRON














                                           0                                         0                                         0



                                       -10                                           -to                                    -30



                                       .20                                           .20                                    -20



                                       -30                                           .30                                    -30



                                       -40                                           -40                                    -40



                                       -50                                     L9    -50                                    -50



                                       -60                                           -60                                    -60



                                       -70                                           -70                                    -70



                                       _90                                           -80



                                       -90                                           .90                                    -90
                                           100 200   300   400   500   600           10    15     20      25     30            20 30  40  50   60  70  80   90
                                                MANGANESE (ppm)                             NICKn (ppm)                                 ZINC (Rm)






                                                                                           88








                                                                                    Station 7


                                            0                                                                     0



                                      -10                                                                      -10



                                      -20                                                                      -20



                                      -30                                                                      -30



                                      -40                                                                      AO



                                      -50
                                   w                                                                           so


                                      -60                                                                      -60


                                      -70                                                                      -70


                                      -80   -                                                                  -80


                                      -90                                                                      -90
                                            0      20        40        60       80        100                     0        20        40       60        so       100
                                                          WATER                                                                         %

                                                                                                                        ,SAND-,lSILT -,CLAY



                                            0                                                                     0



                                      -10                                                                      -10



                                      -20                                                                      -20



                                      -30                                                                      -30



                                   E                                                                           40
                                      -40



                                      -50                                                                      -50



                                      -60                                                                      -60



                                      -70                                                                      -70



                                      -80                                                                      -80 -


                                      -90.                                                                     -90
                                            0.5  1     1.5     2     2.5    3      3.5    4                       0    0.05    0.1   0.15   0.2    0.25   0.3    0.35
                                                                 %                                                              NITROGEN (-/o)

                                                 -,CARBON.6. SULFUR
                                                                                             89








                                                                                                              Station 7


                                                     0                                                        0                                                     0



                                                  -10                                                         -10                                                   -10



                                                  .20                                                         .20                                                   -20



                                                  -30                                                         .30                                                   .30



                                                  -40                                                         -41



                                                  .30                                                                                                               .50



                                                  -60                                                         .60                                                   -60



                                                  .70                                                         .70                                                   -70






                                                  .90
                                                     60    70     so    90     100   110   1"                 8   10     12    14     16    18    20                2   2-5   3    3.3   4    4.3        5.5
                                                               CHROMIUM (ppm)                                          COPPER (ppm)                                              IRON














                                                     0                                                        0                                                     0



                                                  -10                                                         -10                                                   -10



                                                  -20                                                         .20                                                   -20



                                                  .30                                                         .30                                                   -30


                                                  -40                                                   E     40                                                    -40



                                                 Lp .50                                                 w     .50                                                   .50



                                                  -60                                                         -60                                                   -60



                                                  .70                                                         .70                                                   -70



                                                                                                              -90                                                   .80



                                                                                                              -90                                                   -90
                                                     230       300      350       400      450                15    20      25     30      33      40               30 60 70 go 90 10,D 110 120 1" 140
                                                              MANGANESE (ftm)                                           NICKEL (ppm)                                             mc (mm)







                                                                                                                      90










                                              DEPTH (cm)                                                          DEPTH (cm)













                                              DEPTH (cm)                                                         DEPTH (cm)








                                                                                  Station 9


                                        0                                         0



                                        40,                                    -10                                       .10.



                                        -20 -                                  .20                                       .20 -



                                        -30                                    .30                                       -30

                                                                             E                                           E

                                        -40                                    -40                                       -40
                                  F-

                                                                            Q

                                        -30                                    .50                                       .30



                                        .60                                    .60                                       40



                                        .70                                    -70                                       .70



                                        .40                                    .90         -L I   L                      .80
                                        43 50 55 60 65 70 75 9D 85 90             5 6   7  8  9  10 11  L2 13 14                  2-5     3      3.5     4
                                               CHROMIUM (,Wm)                             COPPER (ppm)                               IRON















                                        0                                         0                                        0



                                    -10                                        -10                                       -10



                                    -20                                        -20                                       -20



                                                                               -30                                       -30



                                    -40                                        -40                                       @0
                                  ul                                        Lu                                         w


                                                                               .50                                       .50



                                    -60                                        -60                                       -60


                                    .70                                        .70                                       .70
                                    .401 . . . . . . . . . . .       1
                                        200 220 240  260  290  300  320        .80                                       40
                                        210  230  250  270  290  310              17 18 19 20 21 23 ' .4 25 26 27 22       30  40  30  60  70  80   90  10D
                                              MANGANESE (PIM)                             NICKEL CMn)                                23NC ("m)






                                                                                         92








                                                                                 Station 10


                                                                          0




                                                                       -10




                                                                       -20




                                                                       -30




                                                                       40




                                                                       -50




                                                                       -60




                                                                       -70 -




                                                                       -90
                                                                            0       20       40        60       so       100
                                                                                          WATER (0/*)




                                                                          0




                                                                       -10




                                                                       -20




                                                                       -30




                                                                       -40




                                                                       -50




                                                                       -40




                                                                       -70




                                                                       -90
                                                                            0       20      .40        60       so       100


                                                                                   SAND -, SILT       -,CLAY


                                                                                            93























                                                                                                                 DEPTH












                                                                                    CA    iA

                                              DEPTH














                                                                                                                  DEPTH







                                                                                         00


                                                                                         C,




                                                                                         tri
















                                                                 DEPTH (cm)                                                                                    DEPTH (cm)









                                    rn










                                                                 DEPTH (cm)                                                                                    DEPTH (cm)










                                      tj









                                                                 DEPTH (cm)                                                                                    DEPTH (cm)
















                                                                                                                                DEPTH (cm)                                                                                                                                                                            DEPTH (cm)
                                                                                                                                                                                                                                                                                                                 f.,







                                                               ol













                                     CN



                                                                                                                                  DEPTH                                                                                                                                                                               DEPTH (cm)






                                                           z








                                                                                   Station 11

                                                                                                                                           0



                                                                                                                                           .5



                                       -10                                              -10                                                -10



                                       -15                                              -15



                                       -20
                                                                                        .20                                                -20



                                       .23
                                                                                        -25



                                       .30
                                                                                        .30                                                -30



                                       .15
                                                                                        -35                                                -35


                                       -40 . . . . . .
                                       'n 29 30 31 32 33 34 35 36 37 38 39              40                                                 .40
                                                       ppm                              3     4      5      6       7      8               1   1.1    1.2  1.3   IA    lj    1.6
                                               CHROMIUM (ppm)                                    COPPER (ppin)                                         IRON














                                       0                                                0                                                              Station I I
                                                                                                                                           0


                                       .5                                               .5
                                                                                                                                           -3


                                       -10                                              .10
                                                                                                                                           -10


                                       -13                                              -15
                                                                                                                                           -13
                                                                                  E

                                       -20                                              .20
                                                                                                                                           .20

                               cl                                                 a

                                       -25                                              -25                                                .23



                                       .30                                              -30                                                -30



                                       -35-                                             .35                                                .15



                                       -40                                              -40                                                .40 "---j        L
                                       120 130 140 150 160 170 190 190 200 210 220      10   11    12    13   14    15    16               20  25     30   35    40   45     50
                                             MANGANESE (ppm)                                      NICKEL (pprn)                                      ZINC (M=)







                                                                                               97

















                                                     DEPTH (cm)                                                                   DEPTH (cm)









                   cn












               00



                                                      DEPTH                                                                      DEPTH (cm)
                                                                     lo!@   41                                  4.




                        Z
                                                                                                                         - - - - - - - - - - - -








                                                                                Station 12

                                  0                                                                                               0



                                -10.                                            -10.



                                -20                                             .20                                             .20



                                .30-                                            -30                                             .30



                                10                                                  0                                           40



                             LU .30                                             .30                                             .50
                             cl                                                                                              Q


                                -60                                             .60                                             .60



                                .70                                             .70                                             .70



                                -W                                              -W



                                                                                .90                                             -90            . . . . . .
                                  33  60  65   70  75  20   83  90  95              7 8 9 10 It 12 13 14 15 16 17 19 19           2.4 2.6 2.8 3 3.2 3A 3.6 3.3 4 4.2
                                           CHROMWM (pin)                                     COPPER (Ppm)                                       [RON














                                  0                                                 0                                             0



                                -10                                             -10                                             -10



                                .20                                             -20                                             -20



                                -30                                             .30                                             -30



                                -40                                                                                             -40



                                                                              UJ .30                                            .50


                                .60                                             .60                                             40


                                -70
                                                                                .70                                             -70



                                                                                -80 -                                           .80


                                -90
                                  ,so  200   220   240  260   280   300         .90                                             .90
                                     190  210   230  250   270   290                19 1.0 21 n 23 24 25 26 27   23 29            30  40 30 60 70 80 90 100 110 120
                                           MANGANESE (ppm)                                   NICKEL (ppm)                                      ZINC (A=)








                                                                                          99



















                                               DEPTH                                                             DEPTH (cm)








                                                                                         >



                       tj                                                                  s


                       t9








                                               DEPTH (cm)                                                        DEPTH (cm)








                                                                Station 13





                          -10                                    -10.                                  -10




                          .20                                    .20                                   -20




                          .30                                    -30                                   .30




                         0-40                                    -40                                 0 -40




                          .50                                    .50                                   .50




                          .60                                    -60                                   -60



                          -70                                    -70                                   .701
                             3 4 3 6 7 2 9 10 It 12 13 14          0     ai      1     1.3     2          at  0.2   0.3  GA   0.5   M6
                                   CHROMIUM (ppm)                         COPPER (ppm)                             IRON














                             0                                     0                                      0




                          -10                                    .10                                   -10




                          .20                                    .20                                   -20




                          -30                                    -30                                   -30



                         w                                     Lu                                    Lu
                         C-40                                  a 40                                  Q 40




                          -50                                    -50                                   -30




                          .40                                    -60                                   .60




                             L                                   .70                                   .70
                                             70  90 90 too         3   4    5    6    7  a     9          4 3 6 7 8 9 10 It 12 13 14 15
                                   MANGANESE (PPM)                         NICXEL Wm)                              ZINC (ppm)







                                                                        101

















                                               DEPTH (cm)                                                          DEPTH (cm)

                                                                               C@







                                                                                          >














                                                DEPTH (cm)                                                         DEPTH (cm)


                                                                                                       Im It 0   a




                      z

















                                                      DEPTH (cm)                                                                     DEPTH (cm)





















                                                      DEPTH (cm)                                                                    DEPTH (cm)
                                                                                                               is





                             z










                               15



                                                      DEPTH (cin)                                                                   DEPTH (cm)
                                        [IV








                    Table XIL       Enrichment factors for metals analyzed in core sediments.


                               Sample interval                Enrichment factor relative to average
                     Station          (cm)                       continental crust (Taylor, 1964)
                          ;ff       -
                                Upper FLower            Cr          Cu           Mn            Ni            Zn
                          1       0         -4        1.46        0.57         0.67          0.71          2.91

                          1      -10       -14        1.36        0.45         0.62          0.63          2.56

                          1      -20       -24        1.27        0.26         0.53          0.53          1.48

                          1      -30       -34        1.35        0.26         0.65          0.59          1.41

                          1      -40       -44        1.37        0.28         0.65          0.61          1.46

                          1      -50       -53        1.37        0.24         0.65          0.55          I.A5

                          1      -60       -63        1.33        0.24         0.69          0.55          1.42

                          1      -72       -75        1.29        0.28         0.58          0.56          1.42

                          2       0         -2        1.50        0.58         0.63          0.75          2.74

                          2       -2        -4        1.50        0.51         0.70          0.63          2.77

                          2       -4        -6        1.48        0.54         0.63          0.60          2.91

                          2       -6        -8        1.57        0.53         0.69          0.76          2.81
                          2       -8       -10        1.49        0.51         0.69          0.65          2.62
                          2      -18       -20        1.51        0.47         0.63          0.67          2.77

                          2      -24       -16        1.50        0.35         0.61          0.66          1.67

                          2      -32       -34        1.55        0.41         0.74          0.75          1.77

                          2      -40       -42        1.51        0.38         0.78          0.77          1.59

                          2      -50       -52        1.49        0.33         0.75          0.68          1.63

                          2      -58       -60        1.14        0.21         0.35          0.25          0.56

                          3       0         0         1.57        0.53         0.92          0.96          2.83

                          4       0         -4        1.49        0.77         0.60          0.59          2.68

                          4       -8       -12        1.44        0.37         0.63          0.71          1.93

                          4      -16       -20        1.30        0.27         0.69          0.62          1.40










                                                                  104









                       Sample interval               Enrichment factor relative to average
             Station         (cm)                       continental crust (Taylor, 1964)
                       Upper    Lower          Cr          Cu          Mn             Ni           Zn

                4         -24      -28       1.33         0.28         0.64         0.61         1.40

                4         -32      -36       1.29         0.27         0.61         0.64         1.39

                4         -40      -44       1.32         0.24         0.68         0.59         1.45

                4         -50      -54       1.26         0.22         0.64         0.53         1.36

                4         -60      -64       1.21         0.23         0.61         0.52         1.29
                -5        0        0         1.52         0.59         0.78         0.68         2.37
                6         0        -2        1.36         0.46         0.55         0.62         2.51

                6         -4       -6        1.40         0.47         0.59         0.62         2.47

                6         -12      -14       1.35         0.34         0.61         0.56         1.95

                6         -24      -26       1.39         0.31         0.55         0.54         1.73

                6         -34      -36       1.37         0.30         0.57         0.61         1.50

                6         -46      -48       1.44         0.31         0.60         0.64         1.57

                6         -58      -60       1.34         0.27         0.75         0.59         1.53
                6         -78.     -80       1.30         0:22         0.76'        0.52         1.41
                7         0        -2        1.42         0.53         0.52         0.60         2.88

                7         -4       -6        1.34         0.42         0.47         0.55         2.30

                7         -8       -10       .1.36        0.36         0.48         0.56         1.95

                7         -12      -14       1.43         0.35         0.66         0.56         2.01

                7         -24      -26       1.30         0,23         0.46         0.50         1.38

                7         -36      -38       1.24         023          0.52         0.52         1.31

                7         -48      -50       1.25         0.21         0.55,        0.55         1.35

                7         -60      -62       1.25         0.22         0.50         0.54         1.35

                7         -72      -74       1.26         0.22         0.52         0.54         1.35

                7         -84      -86       1.24         0.22         0.51         0.51         1.27

                8         0        0         1.44         0.74         0.41         0.76         2.22

                9         0        -2        1.39         0.50         0.56         0.61         2.66

                9         -6       -8        1.40         0.51         0.56         0.63         2.70

                9         -14      -16       1.40         0.45         0.53         0.66         2.19



                                                          105









                               Sample interval               Enrichment factor relative to average
                     Station          (cm)                       continental crust (Taylor, 1964)
                               UpperTower.             Cr           Cu          Mn             Ni    T      Zn
                        9        -24      -26        1.30         0.27          0.49         0.55          1.48

                        9        -34      -36        1.35         0.29          0.60         0.58          1.50

                        9        -50      -52        1.26         0.27          0.60         0.58          1.45

                        9        -72      -74        1.33         0.24          0.67         0.65          1.36

                        10        0        -3        1.41         0.63          0.59         0.66          2.53

                        10        -5       -8        1.38         0.55          0.60         0.60          2.61

                        10       -14      -17        1.37         0.51          0.59         0.62          2.63

                        10       -27      -30        1.31         0.36          0.67         0.60          1.65

                        10       -45      -48        1.36         0.29          0.59         0.60          1.49

                        10       -57      -60        1.35         0.30          0.60         0.60          1.46

                        10       -72      -75        1.34         0.28          0.63         0.56          1.45

                        11        0        -3        1.58         0.59          0.73         0.82          2.70

                        11        -9      -12        1.56         0.57          0.72         0.69          2.85

                        11       -17      -20        1.46         0.48          0.73         0.73          2.40

                        11       -26      -29        1.36         0.45          0.80         0.67          1.78

                        11       -34      -37        1.38         0.36          0.68         0.67          1.57
                        1@        0       .-2        1.35         0.58          0.47         0.59          2.89

                        12        -6       -8        1.35         0.58          0.50         0.64          2.84

                        12       -14      -16        1.29         0.56          0.43         0.59          1.87

                        12       -24      -26        1.34         0.29          0.55         0.56          1.47

                        12       -34      -36        1.26         0.26          0.50         0.47          1.26

                        12       -50      -52        1.32         0.32          0.47         0.55          1.22

                        12       -68      -70        1.32         0.27          0.47         0.55          1.35

                        12       -84      -86        1.25         0.25          0.44         0.53          1.30

                        13        -4       -6        1.50         0.49          1.05         2.53          2.93

                        13       -14      -16        1.37         0.52          1.20         1.53          2.01

                        13       -36      -40        1.36         0.33          1.02         0.75          2.02

                        13       -48      -50        1.32         0.17          0.69         0.84          1.97



                                                                  106








                       Sample interval               Enrichment factor relative to average
             Station         (cm)                       continental crust (Taylor, 1964)
                 4     Upper     Lower         Cr          Cu           Mn            Ni           Zn

               13       -64       -66        1.55         0.12        0.80          2.06         1.61

               14        0         -3        1.45         0.49        0.67          0.76         2.48

               14       -22       -25        1.47         0.51        0.61          0.71         2.63

               14       -27       -30        1.49         0.74        0.66          0.92         2.67

               14       -40       -43        1.51         0.52        0.69          0.77         2.39

               14       -57       -60        1.48         0.63        0.61          0.69         2.57

               14       -75       -78        1.52         0.39        0.49          0.72         1.58

               14       -80       -83        1.66         0.50        0.38          0.88         2.69

               14       -84       -86        1.87         0.52        0.44          1.00         1.97

               14       -94       -97        1.37         0.35        0.32          0.70         1.81

               14       -101      -103       1.31         0.38        0.34          0.70         1.55

               14       -105      -106       0.99         0.54        0.28          0.77         1.93

               14       -107      -110       1.64         0.54        0.39          0.69         1.36

               14       -117      -120       1.98         0.35        0.41          0.74         1.32

               14       -125      -127       1.26         0.27        0.37          0.67         1.54


























                                                          107






















                                                                                                                  I


















                                     Plots of enrichment factors versus depth in cores.























                                                             108





                                                                                 0











                                               Station 1



                        -10 -



                        -20


                     /-"N-30 -


                        -40 -



                        -50 -



                        -60 -



                        -70 -


                        -80 1
                             0     0.5      1       1.5     2      2.5      3
                                         Enrichment Factor
                                 Cr      Cu , Mn -,,- Ni        Zn




                                           109











                                                      Station 2
                                  0



                               -10




                               -20




                               -30




                             0-4




                               -50




                               -60




                               -70
                                   0      0.5       1      1.5      2      2.5      3
                                                Enrichment Factor
                                        Cr      Cu      Mn -, Ni        Zn




                                                  110











                                   Station 4



                  -10




                  -20 -



                5-30 -



                 0-40




                  -50




                  -60




                  -70
                     0     0.5   1     1.5   2     2.5   3
                               Enrichment Factor

                         Cr    Cu    Mn   Ni    Zn











                                                    Station 6
                                 0



                              -10 -



                              -20 -



                              -30  -



                                40


                             0--50 -


                              -60  -



                              -70  -



                              -80  -



                              -90
                                   0     0.5      1      1.5     2      2.5      3
                                               Enrichment Factor
                                       Cr     Cu , Mn -,,- Ni        Zn




                                                 112











                                             Station 7
                          0



                        -10



                        -20 -



                        -30 -



                        -40


                      0--50


                        -60 -                  1110


                        -70 -



                        -80 -



                        -90
                            0     0.5      1      1.5      2      2.5     3
                                        Enrichment Factor

                                Cr      Cu --A-Mn Ni -.,-Zn




                                          113











                                                            Station 9
                                      0



                                   -10 -



                                   -20 -



                                   -30 -



                                   -40



                                   -50



                                   -60 -



                                   -70 -



                                   -80
                                        0      0.5       1       1.5       2       2.5        3
                                                      Enrichment Factor
                                             Cr      Cu -A, Mn -,- Ni           Zn




                                                        114











                                            Station 10
                          0         Agw


                       -10 -



                       -20 -



                       -3 0



                       -40



                       -50



                       -60 -



                       -70



                       -80
                            0     0.5      1      1.5      2      2.5     3
                                        Enrichment Factor

                             -,Cr Cu Mn -,Ni Zn'




                                          115











                                                    Station 11
                                 0



                                -5



                              -10







                              -20 -



                              -25 -



                              -30 -



                              -35 -



                              -40
                                   0     0.5      1       1.5     2      2.5      3
                                               Enrichment Factor

                                    -,Cr Cu Mn Ni Zn




                                                 116











                                                  Station 12
                              0



                           -10  -



                           -20  -



                           -30  -



                            40  -



                           -50  -



                           -60


                           -70



                           -80  -



                           -90
                                0      0.5      1       1.5      2       2.5       3
                                             Enrichment Factor

                                    Cr       Cu      Mn      Ni       Zn





                                               117











                                       Station 13
                         0



                       -10 -




                       -20 -




                       -30 -


                    4Z
                     4-4
                      Cl,                 w
                      0-40 -




                       -50 -




                       -60 -


                       -70 1
                           0   0.5    1    1.5    2    2.5    3
                                   Enrichment Factor

                             Cr    Cu    Mn -, Ni    Zn




                                     118











                                              Station 14
                            0










                          -50









                         -100










                         -150
                             0      0.5      1      1.5     2      2.5     3
                                         Enrichment Factor

                                 Cr      Cu , Mn        Ni      Zn




                                           119








                  Table XIII.       Mean and standard deviation (cr) of the variation values calculated for
                  sediments below 30 cin in the sediment column. The mean and RF values are used to
                  identify significantly low or high variation values (see Table XIV).


                        Metal               Mean               Cr                2cr               3a

                          Cr                 0.01              0.17              0.34              0.50

                          Cu                -0.02              0.23              0.46              0.69

                          Fe                 0.05              0.28              0.57              0.85

                          Mn                0.00               0.21              0.43              0.65

                          Ni                 0.02              0.27              0.54              0.82

                          Zn                0.0                0.20              0.39              0.60











































                                                              120








            Table XIV.          Variation values for metal concentration relative to background levels.
            Variation values were calculated using equations 2 and 3 (see explanation in text). Values
            exceeding 3a (refer to Table XM) are bolded.


                        Sample interval                   Variation from background levels
              Station           (cm)               (calculated using equations 2 and 3- see text for
                                                                        explanation)
                         Upper Lower             Cr        Cu         Fe         Mn            Ni         Zn

                 1          0         -4      0.02        0.94       -0.09       0.02        0.12       0.91

                 1          -10       -14     0.22        0.85       0.19        0.20        0.26       1.15

                 1          -20       -24     -0.06       -0.02      -0.02       -0.14       -0.11      0.02

                 1          -30       -34     0.10        0.07       0.07        0.16        0.09       0.07

                 1          -40       .-44    0.05        0.06       0.00        0.09        0.07       0.05
                 1          -50       -53     0.00        -0.05      -0.06       0.08        -0.03      0.00

                 1          -60       -63     0.04        0.01       0.00        0.21        0.02       0.04

                 1          -72       -75     -0.03       0.13       -0.04       -0.01       0.01       0.01

                 2          0         -2      -0.17       0.50       -0.24       -0.27       -0.12      0.39

                 2          -2        -4      0.02        .0.56      -0.06       -0.02-      -0.11      0.71

                 2          -4        -6      0.11        0.88       0.05        -0.02       -0.07      0.99

                 2          -6        -8      0.18        0.82       0.04        0.06        0.18       0.92

                 2          -8        -10     0.09        0.73       0.00        0.04        0.00       0.75

                 2          -18       -20     0.07        0.52       -0.01       -0.10       -0.04      0.78

                 2          -24       -26     0.26        0.57       0.09        0.15        0.30       0.32

                 2          -32       -34     -0.26       -0.05      -0.35       -0.26       -0.23      -0.22

                 2          -40       -42     0.22        0.32       0.17        0.23        0.20       0.14

                 2          -50       -52     0.45        0.51       0.34        0.51        0.38       0.45

                 2          .-58      -60     -0.45       -0.51      -0.33       -0.65       -0.75      -0.75

                 3          0         0       0.25        0.60       0.37        0.24        0.21       0.87

                 4          0         -4      0.00        1.35       -0.10       -0.15       -0.15      0.66

                 4          -8        -12     0.09        0.29       0.02        0.00        0.15       0.35

                 4          -16       -20     0.13        0.07       0.17        0.27        0.16       0.14

                 4          -24       -28     -0.01       -0.09      0.00        0.00        -0.02      -0.04



                                                               121








                               Sample interval                  Variation from background levels
                     Station         (cm)                (calculated using equations 2 and 3- see text for
                        9                                                    explanation)
                                Upper     Lower        Cr        Cu          Fe   T     Mn         Ni         Zn
                        4        -32       -36      0.12       0.05       0.16        0.13       0.22       0.13

                        4        -40       -44      0.08       -0.01      0.06        0.23       0.13       0.11

                        4        -50       -54      0.00       -0.09      0.03        0.15       0.00       0.02

                        4        -60       -64      0.02       -0.03      0.09        0.14       0.02       0.02

                        5         0         0       0.35       1.32       0.27        0.38       0.18       0.88

                        6         0         -2      0.04       0.67       0.00        -0.09      0.06       0.79

                        6         -4        -6      0.10       0.77       0.03        0.00       0.09       0.80

                        6        -12       -14      0.08       0.27       0.06-       0.06       -0.01      0.46

                        6        -24       -26      -0.03      0.10       -0.09       -0.15      -0.14      0.13

                        6        -34       -36      0.21       0.34       0.15        0.10       0.22       0.23

                        6        -46       -48      -0.33      -0.33      -0.39       -0.41      -0.34      -0.32

                        6        -58       -60      -0.12      -0.16      -0.11       0.06       -0.15      -0.07

                        6        -78       -80      0.01       -0.07      0.0,0       0.34       -0.04      0.04

                        7         0         -2-     -0.03      @0.97      -0.12       -0.20      -0.01      0.86

                        7         -4        -6      0.01       0.66       -0.03       -0.20      -0.03      0.63

                        7         -8       -10      0.02       0.41       -0.04       -0.20      .-0.01     0.38

                        7        -12       -14      -0.27      -0.05      -0.35       -0.25      -0.33      -0.05

                        7        -24       -26      0.00       -0.07      -0.01       -0.20      -0.09      0.00

                        7        -36       -38      0.06       0.01       0.11        -0.02      0.03       0.06

                        7        -48       -50      0.01       -0.07      0.04        0.00       0.06       0.04

                        7        -60       -62      0.02       -0.01      0.04        -0.08      0.06       0.04

                        7        -72       -74      -0.03      -0.03      -0.02       -0.07      0.02       -0.01

                        7        -84       -86      0.02       0.00       0.04        -0.04      0.02       -0.02

                        8         0         0       -0.37      0.75       -0.43       -0.59      -0.21      -0.08

                        9         0         -2      -0.02      0.65       -0.07       -0.14      -0.03      0.76

                        9         -6        -8      0.01       0.73       -0.05       -0.13      0.02       0.82

                                 -14       -16      -0.06      0.40       -0.11       -0.24      -0.01      0.38



                                                                    122








                         Sample interval                   Variation from background levels
              Station           (cm)                (calculated using equations 2 and 3- see text for
                                                                         explanation)
                                                                             1                -]@7
                         Upper      Lower        Cr         Cu          Fe          Mn           17         Zn
                 9         -24        -26      0.25       0.25        0.26        0.03        0.19        0.33

                 9         -34        -36      -0.03      0.00        -0.06       -0.06       -0.06       0.00

                 9         -50        -52      -0.01      -0.05       0.05        0.00        -0.01       0.05

                 9         -72                 -0,05      -0.18       -0.07       0.04        0.04        -0.10

                 10         0         -3       0.06       1.32        -0.01       -0.04       0.13        0.79
                 10-        -5        -8       0.10       1.16        0.05        0.05        0.08        0.95
                 10        -14        -17      0.03       0.82        0.01        -0.04       0.03        0.85

                 10        -27        -30      0.08       0.47        0.09        0.18        0.10        0.26

                 10        -45        -48      0.06       0.06        0.04        -0.02       0.03        0.07

                 10        -57        -60      0.10       0.19        0.07        0.06        0.11        0.11

                 10        -72        -75      0.07       0.12        0.04        0.11        0.04        0.09

                 11         0         -3       0.21       1.06        0.05        0.15        0.29        0.88

                 11         -9        -12      0.00       0.74        -0.14       -0.03       -0.07       0.66

                 11        -17        -20      0.12       0.72        0.07        0.14        0.14        0.67

                 11        -26        -29      0.36       1.07        0.40        0.63        0.36,       0.61

                 11        -34        -37      0.06       0.26        0.08        0.06        0.05        0.10

                 12         0         -2

                 12         -6        -8       -0.04      1.08        -0.07       -0.21       0.05        0.90

                 12        -14        -16      -0.08      0.92        -0.07       -0.33       -0.05       0.25

                 12        -24        -26      -0.12      -0.06       -0.14       -0.21       -0.15       -0.09

                 12        -34        -36      -0.05      0.00        -0.02       -0.16       -0.17       -0.10

                 12        -50        -52      -0.19      0.01        -0.20       -0.37       -0.21       -0.30

                 12        -68        -70      0.02       0.08        0.00        -0.20       -0.01       -0.02

                 12        -84        -86      -0.06      0.00        -0.03       -0.26       -0.06       -0.08

                 13         -4        -6       -0.26.     -0.25       0.25        -0.28       0.50        0.08

                 13        -14        -16      -0.17      -0.02       0.53        0.02        0.12        -0.08

                           -36        -40      -0.21      -0.11       -0.13       0.13        -0.19       0.02



                                                               123
                 13








                                 Sample interval                  Variation from background levels
                      Station         (cm)                (calculated using equations 2 and 3- see text for
                          4                                                   explanation)
                                                                                                1     j@7
                                 Upper     Lower        Cr    L-Cu             Fe   T    Mn            17        Zn
                        13        -48       -50       0.23       -0.51      1.18         -0.08.    -0.02       0.39

                        13        -64       -66       0.30       -0.69      0.90         -0.04     1.18        0.03

                        14         0         -3       0.43       0.90       0.55         0.19      0.30        1.11

                        14        -22       -25       1.00       2.21       0.91         0.68      .0.97       2.25

                        14        -27       -30       1.22       2.83       1.73         0.60      1.03        2.25

                        14        -40       -43       0.97       1.80       0.98         0.67      0.80        1.71

                        14        -57       -60       0.04       1.23       -0.09        -0.06     0.11        0.68

                        14        -75       -78       -0.27      0.07       -0.39        -0.47     -0.15       -0.28

                        14        -80       -83       -0.36      0.11       -0.51        -0.67     -0.17       -0.01

                        14        -84       -86

                        14        -94       -97       -0.28      0.08       -0.34        -0.61     -0.10       -0.10

                        14       -101       -103      -0.46      -0.10      -0.48        -0.68     -0.29       -0.40

                        14       -105       -106

                        14       -107       -110      -0.55      -0.18      -0.65        -0.76     -0.55       -0.65

                        14       -117       -120      -0.35      -0.39      -0.58        -0.70     -0.43       -0.59

                        14       -125       -127      0.05       0.23       0.05         -0.31     0.34        0.20





















                                                                      124










                                              APPENDIX IV



          MICROWAVE DIGESTION TECHNIQUE

              The steps in microwave digestion, modified from EPA Method #3051 (Soil Sample
          Digestion Procedure for Floyd Digestion Vessels), are as follows:

              1. Approximately 0.5 g of dried, ground sediment was placed in the teflon
                 digestion vessel.

              2. 2.5 mi concentrated HN03 (trace metal grade) and 7.5 mi concentrated HCl
                 (trace metal grade) was added to the teflon vessel. (Preparation of blanks were
                 made by using 0.5 mi of high purity water plus the acids used in this step.)

              3. Digestion vessel was capped and placed in microwave carousel. A minimum of
                 four vessels were processed in the microwave at a time.

              4. Sediment and acid mixture was digested by irradiating the vessel according to
                 the programmed steps recommended for the number of vessels in the
                 microwave. The sample was brought to a temperature of 175* C in 5.5 minutes,
                 then maintained between 175-180* C for 10 minutes. (The pressure during this
                 time peaks at approximately 6 atm. for most samples.)

              5. The vessel was allowed to cool to room temperature before opening. The
                 contents of the vessel was transferred to 50 mi volumetric flask and diluted with
                 high purity water to 50 mi. (For Fe and Mn analyses, samples were diluted
                 three times or to 150 mi.)

              6. The dissolved samples are transferred to polyethylene bottles and stored for
                 analysis.

              All surfaces that came into contact with the samples were acid washed (3 days 1:1
          HN03; 3 days 1: 1 HCI), rinsed six times in high purity water (less than 5 mega-ohms),
          and stored in high-purity water until use.








                                                    125




















































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                                ---- -                       108 9369