/D. M. Mickelson ... [et al.] Appendix 9. Douglas and Western Bayfield Counties . Mickelson, David M. [Madison, Wis.:Wisconsin Geological Natural History Survey],1977- Shorelines Erosion Michigan, Lake. Shorelines Erosion Superior, Lake. Shorelines Wisconsin. Coast changes Michigan, Lake. Coast changes Superior, Lake. THE SHORE EROSION STUDY Technical Report Appendix 9 SHORELINE EROSION AND BLUFF STABILITY ALONG LAKE MICHIGAN AND LAKE SUPERIOR SHORELINES OF WISCONSIN DOUGLAS AND WESTERN BAYFIELD COUNTIES WISCONSIN POINT TO BARK BAY E. Need COASTAL ZONE M. Johnsm M. Schultz INFORMATION CENTER S. Pulley D. Mickelson T. Edil R. DeGroot A. Bagchi July 1980 GB 459.5 M5 S5 appendix 9 WISCONSIN COASTAL MANAGEMENT Wisconsin Coastal Zone Management Pro! This report has been prepared through the cooperative efforts of the 1--Tisconsin Geological and Matural 'History Survey, the University of Wisconsin (Madison, Milwaulkee, Parkside, and Extension), the T,,Tisconsin Department of Natural Resources, and the Office of Coastal Management, Wisconsin Department of Administration. Assistance was further provided by Owen-Ayres and Associates. This report is being reproduced quickly and in a limited quantity for dissemination to local governments and interested parties. 4dML- Financial assistance for this study has been provided by the Coastal Zone Management Act of 1972 administered by the federal Office of Coastal Zone Management, National Oceanic an4 Atmospheric Administration. US Department of Commerce 2 NOAA Coastal Services Center Library 2234 South Hobson Avenue INTRODUCTION CharleoWn,, SC 29405-2413 This Appendix provides detailed information on shoreline conditions for the Lake Superior shoreline between Wisconsin Point and the mouth of Bark River. The order of i nformational materials in the Appendix is from west to east. The shoreline has been broken down into reaches and by geographic sections within these reaches. (figure 1). Each reach has a general description followed by the detailed information for .the geographic sections within that reach. For each geographic section, a more detailed narrative is presented along with a map and two types of bluff profiles. Shown on the map are the locations of measured profiles, and subsection divisions that are de@;cribed separately. Engineering data such as safety factor, the confi- dence level of this safety factor, and the distance the slope must retreat before'a stable slope angle is obtained (assuming no further wave erosion at-the toe) are also given. The subsection descriptions include the.materials, condition, failure mechanisms, and,degree of vegetative cover of the beach, toe, and bluff within the section. The measured profiles, from bluff top to water's edge, are presented. These profiles show stratigraphy, slope angles, circles of failure, and calculated safety factors for these sites. Finally, a longitudinal,profile of the shoreline of the section, showing the locations and stratigraphy of the measured profiles is given. Section data were collected in the summer of 1979. Locationof geotechnical borings is indicated on Figure 1 at the beginning.of the Appendix. Detailed information pertaining to these boreholes.are included in the Appendix where they occur within.the-reaches. '3 A text describing the borehole site, a location map, and several measured profiles are included. Where data were available, the engineering properties and the borehole log are also given. Geotechnical data were obtained during the summer of 1978. The measured profiles, the safety factors,,and the stability lines will all change through time so some caution is appropriate when utilizing this information. The meaning of abbreviations used in the Appendix is given below. For more detailed description of the methods used in compiling the data, regional interpretations, and conclusions about the engineering characteristics and types of slope failure taking place refer to-the main report (Shoreline Erosion and Bluff Stability Along Lake Michigan and Lake Superior Shorelines of Wisconsin) available from the State Planning Office and the Wisconsin Geological Natural History Survey. 4 Symbols Used @used as nouns and adjectives) b brown br bedrock bd boulders dbr disturbed-bedrock c clay or clayey rst red sandy till co coarse f fine 9 gravel m medium p pebbles r red s sand si silt t till y cobbles SF Factor of Safety A - unsatisfactory (1-00) B - questionable (1.00-1.25) C - satisfactory (1.25) 'Conf.. Confidence Level A - high confidence at borehole B - medium confidence - near borehole stratigraphy visible C - low confidence - away from borehole, stratigraphy questionable SL Stability line - the distance slope must retreat to attain a stable slope angle. This assumes no erosion at toe and unchanged conditions of nature of material and water table. Faack &4c@k ;z ;4JQlJ CIOKt-y 57 in le -.1, tA 6 GEOLOGY Detailed stratigraphic investigations of the bluffs along the Wisconsin shoreline of Lake Superior reveal the presence of three till units. Theoldest till unit is composed of the Jardine Creek till, which can be distinguished by its sandy loam texture (average: 61% sand, 24% silt, 15% clay). This till unit is underlain by Precambrian sandstone througout the study area. The till is exposed in the bluffs between the Iron River and Port Wing and on Bark Point. It is present just below lake level in the western part of the study area. This till was derived from bedrock. The next youngest till units is composed of the Hanson Creek till. This till can be distinguished by its clay texture (average: 10% sand, 32% silt,,58% clay), its relatively browner color (5YR 3/4), and the complex intermingling patterns of red and gray color bands within it This till also has a lower plasticityindex (38) and higher standard penetration.resistance (21) than the clay.facies of the Douglas till unit (45 and 14, respectively). This till unit is exposed in the bluffs from Wisconsin Point to the Iron River and is absent east of the river. This till was derived from lake sediments deposited during the retreat of ice that. deposited the Jardine Creek till. The youngest till unit is composed of the Douglas till. Two tex- tural facies are present within this unit -- the clay facies (average: 10% sand, 26% silt, 64% clay) and the clay-loam facies (average:,40% sand,.27% silt, 33% clay). In.addition, this till can be distinguished by itscharacteristic red color (2.5 YR 4/4) and its occurrence as the surficial unit of the Lake Superior plain. The clay facies is exposed in the bluff from Wisconsin Point to Port Wing while the clay-loam. facies extends from Port Wing to Bark Bay. This till was derived from lake sediments deposited during the retreat of ice that deposited the Hanson Creek till. In addition to these tills a deposit of sand and gravel that comprises nearly all of the bluffs between Port Wing and Herbster and a deposit of fine-sandy silt between Bardon and Haukkala Creeks are significant bluff constituents. Thus there is evidence in northwestern Wisconsin suggesting at least three episodes of glacial activity during Late Wisconsinan time. These episodes are indicated by the presence of the three till units exposed in the bluffs along the Lake Superior shoreline. Although lakes filled the western end of the basin after each of the till units were deposited,,no lake sediments were observed overlying the youngest unit, the Douglas,.till unit. The till units are tentatively correlated with till units described in Minnesota by Wright (and others, 1970) based on lithologic similarities, stratigraphic relationships, and geographic occurrence. The Jardine Creek,till.unit is correlated to sandy till units deposited during the St. Croix and Automba phases in Minnesota; the Hanson Creek till unit to the clayey till units deposited during the Split Rock phase; and the Douglas till unit to the clayey till units deposited during the Nickerson phase. Because they are based on dates from organic materials that could be contaminated, the ages of the phases described by Wright (and others, 1973),may be too old. Based on more conservative reasoning, the glacial 8 glacial episodes recorded in the study area probably occurred between 14,000 and 12,000yrs BP. They may be as young as 10,200 yrs BP. The Lake Superior basin is presently undergoing glacial rebound or uplift in response to the unloading of the ice mass. This.uplift, however, is not occurring uniformly across the basin. The northeast is rising at a faster rate than the southeast. As a result, the basin is being tilted and the water in the lake is rising against the Wisconsin shoreline. This differential uplift has, in part, contributed to erosion processes along the Wisconsin shoreline since waves can more directly act against coastal bluffs and beaches. [0, 4T- !5.9 -0-71 E91 -- I - 6.6 E1.6 D 0.1 -1.9 1.3.2 1 - I Ise E-1 C LV L R Clow SIDE ly; AVERAGE ANNUAL Ft ECESSION RATES IN FEET 193u-,66 -E- I @j 1 1 1938.'76 Itj 1.4 1., 0 2.0 4.6 -6 [0.7 1 0.31 C'. -5- 0.1 3. 1.0 o.4 - - ---- !). 2 12.4 0.4 0.2 0 1.8 11.3 1 1.7 1.1 0 0.9 0.1 o 1.6 0 [19.3 0.4 q. C. 0 111.01 2.1 X to 0.1 6 +1.2 3.9 3. 1 1.51 - 1 40.9 1.4 j 1.9 B.4 3.4 iL CL VE LF, 31 4 A I ORT WING -7, j AVERAGE ANNUAL RECES -E=t OR-! INTAI 19 6 6 -'7 5 Datil 101 -Iva Reach 1 Reach 1 extends from the Minnesota-Wisconsin state line, 3.4,miles to the eastern end of Wisconsin Point. This reach includes Sections 28, 27, 34, and 35 of Township 48 North, Range 13 West in Douglas County. Geologically, this reach is a portion of the bay mount bar which separates Lake Superior from Alllouez Bay. Together with Minnesota Point, this bar is the longest fresh water spit in the world and provides natural harbor protection for the ports of Superior and Duluth. Wisconsin Point is composed of sandy material which has been trans- ported to the western end of the Superior Basin by the littoral currents which trend east to west. The sand is derived from the erosion of shorelines to the east. Beaches are sandy and range from as much as 300 feet wide near the Superior Entry to near zero at the eastern end of this reach. Erosion in this reach varies greatly. The western-half of Wisconsin Point has a stable shoreline, and in some places is experiencing accretion. The area of maximum accretion occurs at the western end where the jetties of the Superior Entry block the littoral movement of material. The eastern half of the reach is eroding at a rate of approximately 1 foot per year. The land is entirely owned by the City of Superior and Douglas County with recreation being the major land use. A sanitary landfill is located in the western section of the reach in an area of active erosion. Alterna- tives for the protection of the landfill are being investigated at the present time. The only shoreline protection structures in this reach are the jetties at the Superior Entry. 12 Borehole Site 1 Borehole Site 1 is located between Reaches 1 and 2, within the corporate boundaries of the City of Superior. Sections 35 and.36 of Township 49 North, Range 13 West comprise this 2.1 mile site. This study area includes Wisconsin Point (the bay mouth bar which separates Lake Superior from Allouez Bay) and the western portion of the red clay bluffs which dominate much of the Douglas County shoreline'. Wisconsin Point occupies nearly all of Section 35. Sand dunes 10 to 15 feet in height are present in the western portion and a wetland is located between Wisconsin Point and the mainland (see Profile I and 2). Beach widths in Section 35 decrease from 75 feet in the west to zero in the east. .The.bluffs located in the eastern portion of Section 35 and in Section 36 average 50 to 60 feet in height. Two stratigraphic units are.identifiable within the bluff face: an upper, redder clay unit and a lower, browner clay unit. This lower layer is exposed at the bluff toe east of Dutchman's Creek to the end of the reach. This browner unit has a higher silt content and a greater percentage of cobble to boulder size clasts. The clay units located in this study area extend eastward through Douglas County and into western Bayfield County. The role of vegetation in bluff stabilization is well illustrated in this study area. In section 35 and the wester 1/4 of Section 36, flows and shallow slides are prevalent where vegetation is absent. Rotational slumping, however, appears to unaffected by the presence of vegetation (see Profiles 6 and 8). Beach widths along the bluffs vary from in excess of 150 feet at the western end to less than 20 feet in the east. The beach environment is highly dynamic along this coast. To illustrate, within a period of oneyear beach widths in some locations increased from zero.to 165 feet (see Profile 4). This change'l*s due, in part, to decreasing lake levels combined with the 13 amount of sand in the littoral system. 14 c b d b c d. NA 5 N A c SF=0.91 p i SF%1.99 SF=2.42 SF=2.45 =2 D 2 665 660 ISO". SAFETY FACTOR (SF) 6 BEACH A-less thant 1.00 5-1.0D to 1.25 5 TOE C-greater than 1.25 4 BLUFF LEVEL 3 STABILITY LINE A-at boreholes 2 couFIDENCE LEVEL (high confidence) s-near boreholes with SAFETY FACTOR ..stratigraphy visible C-no stratigraghy visible (low APPROXIMATE SCALE cor(J"i dence) I inch 1500 feet 15 Borehole Site I Bluff: a) None b) 0 to 20% vegetation with shallow slides, flows, and slumps c) 90% vegetation with occasional slumping icl Toe: a) None b) Flow terraces and slump debris c) 100% vegetation d) Wave cut. Silty-clay exposed Beach: a) 40 to 90 feet, sand b) No beach marsh C) 45 to 165 feet, sand with some gravel d) 15 to 30 feet, sand 16 T.49N.,R13 W-SEC35 100- PROFILE I vegetation so- AB - 4C?a' LwU 60- 40- 20- A dune sand M CO'S 0 40 80 120 160 200 100- PROFILE 2 80- 0% vegetation LL.u 60- U_ 40- 20 marsh beach -sand 0 40 80 120 160 200 100- PROFILE 3 80- vegetation AB 60016 u.j 60- U. A SF= 1.99 40- Slum ;@ b Ilb c k 20- si,c B beach -sand _T_ 40 80 120 160 20-) 17 T49N.,R13W.,SEC 35. 100 - PROFILE 4 80 - vegetation AS - 0% SF=0.9I 60 - 40- 20- si,c B beach -sand I I 0 40 so 120 160 200 100- PROFILE 5 80- SF=2.42 vegetation AS 0% A SC 50% uj U.1 60- LL 8 ,,slump blo k 40- s1'c 20- C beach -sand 0 .40 80 120 160 200 T.49N.,R13W.,SEC 36 100- PROFILE 6 so- vegetation SF=2.45 AS 0% A BC 10% wuj 60 - sic LL p.y,si,c B slump 40- 20- cOncealed C beach sand & cobbles 0 40 80 120 '160 200 T49 N.,R 13W.,SEC 36 100- PROFILE 7 80- SF=Z.02 vegetation AB 10% BC 100% uj 60- CD - 0% Uj U. p,si,c 40-- 8 20- concealed bd,p,si.c D beach -sand 0 40 80 120 160 200 100- PROFILE 8 80- vegetation SF=2.33 AB 100% A BC 10% uj 60- Ui 40- concealed slump 20--_ B y,p,si,c C beach sand 7-7- 0 40 80 120 160. 200 S F= Z .0 2 co ncealed _@c o n c e a Lle d L 0 C A T 1 0 N SGT-1 T49N R13W Sec. 35 Pocket Blow Count (split spoon) Penetrom ter w n Yd WL lp % Clay 01 Depth (kg/P) & c Descri@jtion (ft.) 10 20 30 40 50 60 70 80 90 100 2 2 1 2 3 4 5 qm/cm Clay Silt degree kg/cm of Loil 5 30.5 1.82 66 36 62.0 93.0 clay,red,silty, 10 trc.sand (CH) 34.2 1.82 77.@ 47."' 67.0 90.0 20 25 40.6 1.82 65.4 28.9 79.0 96.0 33.0 0 clay&si It, It. 30 gray,trc.grvl. 35 (CL&ML) 40 45 29.1 1.88 36.( 13J 18.0 95.0 28.0 0.08 50 55 ECB 50.0 60 65 70 75 80 85 90 95 100 105 110 115 120 20 Reach 2 Reach 2 extends from the eastern end of Wisconsin Point to the mouth of the Bois Brule River. The reach includes approximately 18 miles of, shoreline in Sections 35 and 36 of Township 49 North, Range 13 West, Sections 31, 32, 33,.34, 27, 35, 25, and 36 of Township 49 North, Range 12 West, Sections 30, 29, 28, 21, 22, 23, 14, and 13 of Township 49 North, Range 11 West, and Sections 18, 17, 8 and 9 of Township 49 North, Range 10 West in Douglas County. The entire shoreline is made up of high bluffs composed mainly of two clay units. Bluffs average 50 feet in height with a maximum of 80 feet. Three miles west of the Bois Brule River the bluff begins to decrease in height from 50 feet to 30 feet near the mouth of the river. @'Erosi6n rates of 1 to 7-feet per year have been measured along this reach of shoreline. The only portions which appear to be stabilized are near, the mouths of rivers and streams. These streams are actively down- cutting in their headwater reaches, but th e mouths are drowned. Some carrying large quantities of sediment into Lake Superior. Beaches serve as a protective barrier to wave action at these locations. Where no stream is present, beaches are narrow or absent. Waves can easily cross these bedches-and directly attack the bluff toe. Toe erosion over-steepens the bluffstand triggers slides and rotational slumping. Excessive rainfall commonly saturates the upper layers of the clay, decreasing soil strength. As a result, flows and shallow slides are the dominant erosion meachanisms during wet periods. The land is entirely privately-owned with the exception of the eastern- most 1.3 miles of shoreline which is part of the Brule River State Forest. 21 The majority of the land is. undeveloped with access to the shoreline limited to a few section line roads and roads which lead to stream mouths. A park and public boat landing at the mouth of the Bois Brule is maintained by the State of Wisconsin. Only three structures are located within this reach. A timber groin and sunken barge are located at the east side of the Amnicon River. These structures are completely deteriorated and non"functional. Just west of Bardon Creek, a poured concrete groin has developed a beach along its western side. 22 .Section 35,T 49 N, R 13 W The section is located at the base of Wisconsin Point. Along the western third of the shoreline, a moderately-wide, sandy beach is present. Behind most of this beach subsection is the city of Superior's old landfill. The next third of the beach is characterized by the addition of sand to the beach by the deposition of material in long- shore transport. Inland from this beach subsection is a marsh. The last subsection is marked by a forty foot bluff along the shoreline. The bluff is naturally protected by a wide, sandy beach; however, the bluff itself has not stabilized. Failure is predominantly by shallow sliding, but occasional deeper slides are present. The bluff material is red clay, most of which has slumped. The toe is also composed of slumped, red clay. Vegetative cover is quite poor and is restricted to clumps@of sod and occasional small alders moving downslope on slump blocks. Because of its easy access and proximity to Superior, this last subsection is heavily used. 23 SEC35 T49N R13W SAFETY FACTOR A-less than 1.0o B-1.00 to 1.25 C-greater than 1.2S CONFIDENCE LMML A-boreholes (high confidence) B-near boreholes strati-graphy visible C-no stratigraphy visible (low confidence) A CA 3S 24 Sec. 35, T 49 N, R 13 W Bluff- a) absent b) 40 ft; broadly scalloped crest; shallow sliding with occasional moderately deep slides; 10-20% grass, horsetails, some small alders; slumped red clay Toe: a) absent b) slumped red clay, protected, partially vegetated with grass and horsetails Beach. a) spit b) spit backed by lagoon C) 100-150 ft wide; coarse sand with scattered cobbles throughout width and with a concentration of pebbles and granules near the water'sledge 25 120- Profile 3 5 100- ft. to 5 ft -depth so- LU LU 60- 0.77 LL S F 40- 20- rc bc 20 40 60 80 ioO 120 140 160 180 200 220 240 260 2E 120- Profile 3 5 -2 100- ft. to5ft-depth so- SF=0.91 00 LLJ 60- LU LL 40- 20 rc -bE-- 20 40 66 8'0 1 '00 120 140 160 1 0 200 220 240 260 280 120- Profile 100- f Uo 5 f t.depth so- LU LU 60- U_ 40- 20- r @c - 20 40 60 100 120 14'0 1@0 1@0 2,00 220 240 260 280 FEET a T. 4 9 N., R. 13 W,Se c. 35 240- 220- 200- 180- rQ )60- 140 uj ui 120 100 so 60 40- rc rc 20 rc 0 1000 2000 3000 4000 5000 F E E T 27 Section 36 T 49 N, R 13 W The section is located a mile east of Wisconsin Point and is bisected by Dutchman Creek. The bluff is 50 ft. high, except at the streams, and extends throughout the section. At its western end, the bluff is failing by shallow sliding. It is poorly vegetated grass and alder being restricted to slump blocks moving downslope - and is composed of red clay. T he rest of the bluff shows only minor evidence of recent instability. It is well-vegetated with birch, alder, and grass that conceal the bluff materials. West of Dutchman Creek, the sandy beach is wide enough to protect the toe. Eastward, the beach thins considerably and the toe, composed of slumped red clay, shows marked instability. Where the beach is absent, a 10-12 ft. toe scarp is present; renewed bluff instability is expected in these areas. The beach west of Dutchman Creek is heavily used due to its proximity,to Superior and ease of access. 28 SEC 36 T49N R1 3W SA 'ETY A _Jes s tha@i 1.00 B-1-00 to 1.25 C-greater ti,an 1.25 CONFIDENCE LEVEL --@oles- K--@bore (high copfidence) B-near boreholes stratigraphv visible C-no stratigraphy visible (low confidence) V 0 0, 01 00 N cc 0 0 36 ------------------ 29 1120- Profile 7-o-l 100- f t. to 5 t t. dept h S F =0 9:1 so- OW LLI A-E 30", veor-tation LLI 60 B-C 9L)5o vegetation LL 40- 20- rc lump 7- 20 40 60 so 10'0 11210 14'0 160 1 8@0 20'0 220 240 260 2Z3O 120- Profile 3(-,--! 100- ft. t@,-)5ft.dcpth SFWO. 85 so- slump A-B 70-10M, vegetation LU 60- B-C 80re vegetation LLJ several small LL slumps 40- rc 20- - - - - - Thc- - 20 66 @O 100 120 140 160 180 200, 220 240 2160 2@O 120- Profile 36-3 Ico- ft.to 5 ft.depth ,,F-1.016 80- A-S 70-907* vegetation LIJ R-C 0% vegetation ILU 60- A LL 40- slum slump 20- rc s I um 9 /flowing toe bc -lu-P B slump c slump rc @bc 20 40 60 -80 100 120 140 160 11@0 260 2iO 24'0 2@O 2;0 FEET 30 Sec. 36, T 49 N, R 13 W Bluff: a) 45-50 ft high; crest scalloped; numerous shallow slides; vegetati.on (30-60%) confined to clumps of alder and grass on slump blocks; clay b) 45-55 ft high dropping to.4-6 ft at streams; crest generally subdued; well-vegetated (90-100%) with birch, alder and grass; fairly stable of late, clay Toe: a) red clay; slumped; protected by beach b) clay, slumped, protected, vegetated with alder and grass or scarped at large slump blocks c) clays., slumped, partially,protecte'd, failing for 10 ft vertically by shallow sliding with 2-3 ft scarps at base unvegetated A) clays., slumped, unprotected from waves,'failing by shallow sliding and mudflows wi.th 8-12 ft scarps at base, unvegetated e) clays, slumped, partially protected, failing for 10 ft vertically by shallow sliding with 2-3 ft scarps at base unvegetated. Beach: a) very wide (145-150 ft) narrowing evenly eastward to wide (85-90 ft) coarse to medium.sand with cobbles scattered over whole width and with a concentration of pebbles and cobbles 30 ft wide at water's edge: b) wide.(80-90 ft); uniform width; coarse to medium sand with few scattered cobbles over whole width and with a conclusion of pebbles and cobbles 15-20 ft wide at water's edge c) veryjwide (150-180 ft) narrowing steadily to absent, coarse to, medium sand; concentration of pebbles and cobbles 15-20 ft wide at watWs edge; approximately 20-30 ft of back beach near stream is .Vegetated for 250 ft eastward. d) mostly absent (0-5 ft) wholely withi n wash/swash zone sand with occarsional cobbles or boulders e) narrow (20-30 ft) wider west'of stream (40-50 ft); coarse-'medium sand; minor concentration of pebbles and cobbles 5-6 ft near water's edge concentration increases greatly eastward t49'N.,R. 13W,Sec.36 240- 220- 200- 180- uj 160- 140 - uj 120 100 ul so u z 2 3; 60 - C, 40- rc rc rc 20- bc F I 0 1000 2000 3000 AOOO 5000 F E E T 32 Section 31, T 49 N, R 12 W The section lies just outside the city limits of Superior, WI, 3 miles to the west of the mouth of the Amnicon River. Most of the bluff of this section is comprised of slumped red clay. A brown clay can be seen in the banks of a small creek to the eastern end of the section, but its extent and influence on the bluff is unknown. The bluff height rises steadily and evenly towards the east from 40 to 55 ft. except where it drops to meet the three small creeks that enter the Lake. Changes along the bluff face are most noticeable in the character of the vegetative cover. Where vegetation -is up't o 90%, birch and alder with occasional firs are predo.m inant and slope failures appear subdued. These subsections alternate with areas where vegetation is less than 50% and small slumps and shallow slides characterize the bluff face. The vegetation that occurs here is in the form of clumps of sod, with or without trees, which are slowly sliding down slope. Along much of the bluff a 20 foot wide beach protects the toe of the bluff from continuous wave erosion except during intense storms. Where slumps and flows have extended across the beach, the waves are actively eroding at the toe. This section contains two private homesites, but most of the Shoreline is undeveloped and used only occasionally. 33 SEC341" T49N R12W SAFETY FACTOR A-less than 1.00 B-1.00 to 1.25 C-greater than 1.25 COWW IDENCE MTEL A-boreholes (hic.Th confidence) B-near boreholes stratigraphy visible C-no stratigraphy visible (low confidence) E CO A J9 0 C14 C& 0 0, E) 34 Sec..31, T 49 N, R 12 W Bluff: a,- c', and. e). 50-90% vegetated with birch, alder, occasional.fir, with hor'setails in wet or locally failed places; predominantly red clay s,lumped; medium scale rotational,slumps and shallow slides; bluff .crest rises from 40 ft to 50 ft eastward; rounded but commonly .showing a scarp and cut by 1-5 ft ravines. b, d, and f) 10-40% vegetated with alder; birch with grass in clumps moving.downslope, horsetails in west areas; red clay, slumped; bluff surface straight and failing; bluff height 40' rising to 55' to the east Toe: a, h and 1) Moderately well.;- to well-vegetated; slumped red clay. rounded or, in places, a small@scarp, protected from wave attack., except during large storms. b, di f,.i, k, and m) Little or no vegetation; slumped red clay; rounded or producing mudf.lows;..protect.ed from wave attack except during large storms c, e,,g,, And j) Little or no vegetation: slumped red clay; mudflows and eroded clay surfaces; unprotected Beach: a, c, e,@g, and i) Medium rand, with pebble concentration 3.from shore with occasional-boul.ders; 15-20' wide; driftwood accumulation at back of beach b, d, f, and h) Covered, beach absent 35 120- Profile 31- 1 100- cF=1.26 ft. to 5 ft. depth 80- w W 60- U- t a 40- 20- rc bc 20 410 610 80 100 1210 140 160 180 200 2'2 0 240 260 2,80 120- Profile 31 -2 100- ft. to5ft-depth SIF=1.00 so- A-B 9070 VeaC!t.At4,.).j 60- w -C 7,),'; LL C-r , @', @,: 40- r k@f c-,-- t.-. t 20- rc b 26 @6 66 80 100 120 140 .160 180 200 220 240 2@O 2iO 120- Prof i le 31-3 100- ft.to 5 ft.depth so- SF=1.02 w W 60- LL 40- rc 20 bc II I I I I I 20 40 60 86 100 12'0 140 40 140 260 220 240 2@O 2'8 0 FEET F E E T 100 100 cr 'go 9 E 37 Section 32 T 49 N R 12 W. The section is located two and a half miles west of the mouth of the Amnicon River. The western half of the beach is discontinuous, generally 20 ft. wide and sandy; but it is occasionally covered by slumped red clay. The bluff behind this beach subsection is 50 ft. high and the crest is finely-scalloped. Failure is by shallow sliding and the moderate vegetation (30-60%) is restricted to slump blocks moving downslope. The bluff materials are slumped clays, redder at the top of the bluff and browner at the toe. The toe is protected except where failure has pushed it out over the beach. The eastern half of the section has no beach; the toe, of slumped clay, is unprotected from wave action.. The bluff here is 50 ft. high and the crest is more subdued and rounded. It is-well-vegetated (80-90%) with alder, birch, grass and horsetails. Most of the slope appears fairly stable, but a fresh scarp at mid-slope was often noted. This renewed instability is no doubt due to the instability of the toe, which is failing by shallow sliding and flowing, producing a,10-12 ft. scarp in the slumped clay. At the eastern end, the bluff instability has extended back to the crest. The vegatative cover has nearly been destroyed (0-10%) and consists of clumps of alder and grass moving downslope on slump blocks. Here the bluff materials are clearly slumped clays. The shoreline of this section appears to be largely unused. 38 SEC32 T49N R12 W SAFETY FACTOR A-less than 1.00 B-1.00 to 1.2S C-greater than 1.25 CONTIDENCE LEVEL A-boreholes (high confidence) B-near boreholes stratigraphy visible C-no stratigraphy visible (low ................... ..... . ... confidence) A -,eel 0 M In Va 00 06 39 Sec. 32, T 49 N, R 12 W Bluff: a) 45-80 ft high; crest scalloped; shallow slides; vegetation (50-60%) restricted to clump on actively moving slump blocks; clay b) 45-50 ft high; crest subdued; well-vegetated (80-90%) wi 'th alder, birch, some conifer, grass, moss, and horsetails toward the toe; fairly stable of late but fresher a-mid-slope scarp was often noted, clay c) 45-50 ft high, crest newly scalloped; vegetation being destroyed (0-10%); shallow slides, clay Toe: a) mixed-colored clay (red-brown-gray); slumped; generally protected from wave action b) red and brown clay; slumped; under wave attack; failing for 12 ft vertically by shallow slides and mudflows Beach: a) discontinuous (covered by slumped clay occasionally) 0-20 ft; coarse to medium sand with occasional large boulders and pebbles and cobbles at waterline; pebble and cobble concentration decreases to absent eastward b) mostly-absent 0-5 ft; wholely within wash-swash zone; sand with occasional large boulders 40 120- Profile' 32-1 100- lt.to5ft.deptV LU sF ao v 6 LLI 60- LL A-B 20@._, vegetation 3-C 805, vegetation 4ID- rc 20- bc 7- 20 40 60 so 100 120 UO 160 180 200 220 240 260 2W 120- Profile 32-2 100- ft. to 5 ft. dep go- SFol.19 LU 60- LLJ U_ A occassional mid-slope 40- scarps A-B 90% vegetation rc B B-C 100% vegetation 20- bc C 20 40 66 80 100 120 1@0 16'0 180 200 220 240 260 280 120- Profile 32 - 2 100- ft.to 5 ft.dept so- LU ui 60- LL - A numerous shallow SF=1.32, A-B 300; vegetation 40- slides R-C 50-,, vegetation B C-D (M vegetation r 20" bc C flowing and sliding toe Bn c b 20 40 60 100 120 140 160 180 200 240 240 260 280 FEET T- A 9 N., 12 W-,So C. 3 2 240- 220- 200- 180 160- 140- uj UJ 120- 100- 80 - 2,'@ 3 60 40- r c rc 20- bc bc 0 1000 2000 3000 4000 5000 F E E T - - - ---------- 42 Section 33 T 49 N, R 12 W The sectionis located one and a half miles west of the mouth of the Amnicon River. The beach is present only rarely within this section. Where present it is at most 20 ft. wide and is composed of sand, often interfingered or perhaps underlain by clay like that in the toe. The bluff is 50 ft. high and only a very short subsection is well-vegetated and lacking fresh scarps. Failure is by shallow to moderately deep slides and by flows originating on the upper half of the bluff. In one subsection the bluff is actually vertical! Here, failure is by block fall. There appear to be two materials in the bluff - an upper red clay, which is less .stable, and a lower browner clay, which seems to be stronger. A subtle break in slope can often be noted at the contact. The toe. in this section is almost entirely unprotected from wave action. The toe material is the brownish clay, probably in situ. The shoreline .of this section is rarely used. 43 SEC33 T49N R12W f@@V-ETY PACTOR 00 tO 1.25* C-greater than 1.25 CONFIDENCE LEvE VE E A- Or-e-11-es, high cOnfidence) B-near boreholes stratigraphy visible C-110 stratinraphy visible (10,, confidence) a -c N hn 0 a4 0. 44 Sec. 33, T 49 N, R 12 W Bluff- a) 50 ft high; scalloped crest; shallow slides and flows; vegetation on slump blocks only 0-20%, red c1ay over brown clay with red clay slumping over stronger brown clay b) 50 ft high; scalloped crest; shallow slides;.vegetation 80-90% on upper slope transitional between subsections a and c; probably same materials as subsection a. c) 50 ft high; subdued crest; only a very few shallow slides;, vegetation 90-100%; materials the same as subsection a d) 50 ft high; linear crest with very steep scarp; block-fall and very deeprotational slumping; no vegetation, two-fold stratigraphy, red clay over brown clay e) 50 ft high; scalloped crest; shallow slides and flows; vegetation on slump blocks only 0-20%, red clay over brown clay with red clay slumping over stronger brown clay Toe:' a) slumped or in situ clay (browner in color); mostly unprotected; scarp 2-18 ft high. b) protected slumped clay covered by vegetation C) unprotected slumped clay ("talus pile" from Bluff (d)) d) slumped or in situ clay (browner in.color); mostly unprotected; scarp .2-18 ft high Beach: a) discontinuous; mostly absent; if present up to 20 ft wide coarse sand-with pebbles, cobbles and occasional boulders b) absent c) discontinuous, mostly absent; if present up to 20 ft wide coarse .sand with pebbles, cobbles and occasional boulders 45 120- Profile 3 3 - I 100- ft. to 5 t t. depth so- LU SF=1.01 UJ 60- U. B A-S 25F vegetation 40- B-C OIb vegetation 20- bc c 20 40 60 so 100 120 140 160 180 200 220 240 260 '230 120- Profile 3 3 - 2 100- ft. to 5 f t. depth go- SF=0.89 w 60- w LL A A-B 95% vegetation 40- rc 20- bc 4 66 8'0 10'0 126 140 160 180 200 220 240 26'0 280 120- Prof i le 3 3 - 3 100" ft.to 5 ft.depth 80-r LU w 60- SF=1.11 LL A 40 A-B 07* vegetation r 20- bc R - - @bc F r -- bc 20 40 60 80 100 120 140 w 180 200 220 240 2@O 2BO FEET F E E T Z 0 C)l 0 fn LA 9 V 47 Section 34/27 T 49 NR 12.W This section is bisected by the mouth of the Amnicon River. There is very little beach west of the Amnicon; but beginning with the 100 ft. wide spit built westward across the river, a good sandy beach is present eastward for approximately half a mile. The bluff west of the river is fairly uniform, being 33-60 ft. high. It is poorly vegetated, and is actively failing by shallow sliding with some flowing from the upper part. the materials are a red clay, which seems weaker and prone to flowing, over a browner clay, which seems stronger. This difference in strength is frequently revealed by a marked break in slope at the contact, as well as the generally -convex-upward profiles. This difference in strength is also shown in the nature of the bluff east of the river. East of a small creek, the bluff is only 15-25 ft. high and is composed wholely of the brown clay; it holds a 50* slope and the crest is near the shore. As the bluff rises above 25 ft., the slope angle decreases to about 30* and the cr.est.recedes greatly from the shore. The mode of failure changes from blockfall to shallow sliding and flowing. The toe is composed mostly in situ brown clay with some slumped red clay. It is unpro- tected west of the Amnicon and generally protected east of it. The western portion is used by hunters and perhaps by the Camp Amnicon programs, while good access and a public landing insure frequent use on the east side. 48 FACTOR SA A FETY SEC34/27 T49N R12W A-le ss than 1.00 B-1-00 to 1.25 C-greater than CONrFIDr_NCE UVEL A-boreholes high confid.ence) B-near boreholes stratigraphy visible C-no strati-raphy visible (low confidence) a lai0 ml -CI 0 C% hm in 0 Ca 4 P4 R 0%M 4* r4 27 34 49 Sec. 27/34, T 49 N, R 12 W Bluff: a@ 55 ft crest scarped, shallow and moderately deep sliding,'some flow, from upper part; slumped clay (red over brown); vegetated 0-20% alder and grass b) 55 ft crest rounded, shallow slides; slumped clay; vegetation 70-80% alder, birch, grass horsetails c) 55-60 ft dropping at the very eastern end toward 15-20 ft; crest scarped, shallow slides and flows; vegetated 0-10% tree- clumps; break-in-slope evident at red clay-t---brown clay contact d) 15-20 ft falling to 0 ft eastward, minor shallow sliding; 70-90% vegetation, birch alder, grass. e) absent - Amnicon River f) rising to,60 ft and dropping back to 0 ft; scarped, shallow slides; vegetation 60-70% alder-brick-grass 9) absent-stream h) rising quickly to 12 ft then gently to 25 ft; blockfall (50'slope) 0% vegetation; brown clay i) 50-55 ft, rising from 25 ft; shallow slide, some flow; vegetation 20-30% clumps, alder, grass; two clay units Toe: a) unprotected in situ (brown) clay with some slumped (red) clay b) protected and vegetated slumped clay c) unprotected in situ clay d) protected vegetated (0-20%) slumped clay e) absent Amnicon River f) moderately protected slumped or in situ clay g) abse*nt-stream h) protected in situ clay i) partially protected in situ clay 50 cont. Beach: a) absent@ toe water b) maximum of 80 ft; 0 ft at both ends; coarse.sand with cobbles scattered-pebbles concentrated near water c) absent d) 0-5 ft widening eastward to 50-60 ft at river coarse sand with pebbles and granules concluded near water e) spit and beach 80-100 ft wide; coarse sand with some boulders and cobbles at water f) 20-30 ft; coarse sand with scattered cobbles; occasional concentration of pebbles and granules at water g) 0-10. ft discontinuous; coarse sand, boulders frequent 51 120- Profile 34/27-1 100- it. to 5 ft. depth go- LU SF=o.84 UJ 60- A-B 10% vegetation A B-C 75% vegetation 40- B rc 20- bc: C 20 40 60 80 100 120 140 160 180 200 220 240 260 2W tm- Profile 34/27-2 100- ft. to5ft.depth 80- SF=I.o6 LLI 60-A LLJ 40- A-B 0% vegetation rc 20- B @O 46 60 80 100 120 140 1@0 1;0 26 2@0 240 260 2W 120- Profile 3A/ 27 - 3 100- fuo5ft.depth I-- large slump UJI block SF@-0.99 w 60- A-B 5% vegetation LL B-C 40% vegetation C C-D OFS vegetation 40- rc 20- D 'B c bc: C r @b acl @ C rc hCD 20 40 60 so 100 120 140 160 180 200 220 240 260 21iO FEET FEET cr n .n0 AMICON RIVER z f I M a, zs 53 Section 35 T 49 N,R 12 W This section is located between the valleys of Hanson Creek and Middle River inclusive, a half a mile east of the Amnicon River. A good sandy beach, usually about 60 ft. wide, is present throughout most of the section. The bluff is quite discontinuous because of the streams which intersect the shoreline with wide valleys. Where well-expressed, the bluff is 55 ft. high, moderately vegetated, and failing by shallow sliding with some flowing from the upper part. The bluff materials are a brown clay overlain by a red clay but the brown clay is rarely,exposed. Near the streams, the bluff height rises and falls quickly, to and from approximately 30 ft.. 'It is very well vegetated with little evidence of instability. A well graded slope is present at the west side of the Middle River. The toe is protected by the wide beach and is composed of slumped red clay, with infrequent exposures of in situ brown clay. There is public access at the west side of the Middle River, but no landing is present. Use is probably moderate to infrequent. 54 SEC35 T49N R12W SAFETY FACTOR A-less than 1.00 B-1.00 to 1.25 C-greater than 1.25 CONFIDENCE LEVEL A-boreholes (high confidence) B-near boreholes strati-raphy visible C-no stratigraphy visible (low confidence) e 1 W.1 I.C 00 0 0 In in 9L 55 Sec. 35, T 49 N, R 12 W Bluff: a) 50 ft dropping to 0 ft; shallow slide and block fall; 0% vegetation, red and brown clay b) absent c) rising to 50 ft; eastward shallow slides; flows from top 0-5 to 40-50% alder and grass; two clay units d) 30 ft falling to 0 ft; no failure seen; vegetation 95-100%, birch, alder, grass, horsetails e) 50-55 ft; shallow sliding and flows from top; vegetation usually 0-20% alder grass slumped clay f) 30 ft falling to 0 ft; no failure seen; vegetation 95--100%, birch, alder, grass, horsetails absent gentle graded slope - well vegetated h) 0 ft rising to 30 ft; shallow slides and some block fall; 10-20% tree-clumps and horsetails, slumped clay Toe: a) unprotected, in situ brown clay b) absent, C) protected slumped clay, vegetated d) absent;;gentle graded slope - well vegetated e) protected slumped clay Beach: a) mostly absent; interfingered with clay flows b) 40 ft coarse sand with pebbles concentrated near water c) 60 ft; coarse sand, pebbles near water d) absent-Middle River e) 60-80 ft coarse sand; pebbles near water; includes spit 56 120- Profile 35-1 100- ft.to5ft.depth go- ';F=0.74 W W 60- LL A 40 - A-B 0% vegetation rc 20- bc 20 40 60 so 100 120 140 160 180 200 220 240 260 280 Profile 35-1 100- ft. to 5 ft. dep numerous shallow slides SF=0.92 W 60- W LL A-B 0% vegetation 40 B-C 10% vegetation C-D 25% vegetation bc D 20 46 60 80 100 120 140 160 180 200 220 240 260 280 120- Prof ile 100- ft.to, 5.ft.dept so- Ui W 60- LL 40- 20- f c --@@bc 20 40 60 80 100 120 140 160 180 260 22'0 240 2@O 280 FEET T.4 9 N., R-12 W,SOC-35 240- 220- 200- 180- 160 140 120 loo A u 80 2 0 w c 60- 40- rc rc 20- bc bc rc L12bc . I V I i I I I I 0 lodo 2000 3000 AOOO 5000 F E E T 58 Section 36/25, T 49 N R 12 W This section is bounded on the west by the Middle River and on the east by the Poplar River Road. Throughout the section, the bluff is composed of red and brown clay. The brown clay is beneath the red clay stratigraphically, and occasionally.exposed at the toe. At two locations, coarse sand with gravel lenses is exposed in the lower 15 ft. of the bluff; however, this sand is not laterally extensive and makes up only a small percentage of the bluff. The bluff face consists of alternating subsections of differing vegetative cover. The well-vegetated parts include thickets of small alder with poplar and birch. In these subsections, the slumps and shallow slides that have occurred are subdued and vegetated although a scarp at the crest is common. The less vegetated reaches consist of alder and birch rooted in sod clumps moving slowly downslope. Medium scales slumps and shallow 'slides occur in the last vegetated subse ctions more frequently. Occasional large slump blocks, now forming the toe, have carried a large amount of vegetation and red clay down slope. Ponding may be present at the backs of the blocks as shown in RP 36/25-2. Except at either end of the section, where it is between 20 and 50 feet wide, the sandy beach is narrow, of variable width, and in many places consists only of a swash zone. Thus the toe, of slumped clay, is unprotected from wave action. Access to this section is fair and it is used only occasionally. 59 SE036/26 T49 N Al 2 W SAFETY rACTOR A-less than 1.00 B-1.00 to 1.2S C-greater than 1.25 CONFIDENCE LEVEL A-boreholea (hIgh confidence) B-near boreholes . stratigraphy visible C-no stratigraphy visible (low confidence) A y A U3 36 60 Sec. 36, T 49 N, R 12 W Bluff: a) 90-1.00% vegetati.on; with alder, grass with occasional birch and conifer; slumped red clay wi.th brown clay occasionally exposed in slumped toe; subdued slum Mocks; crest scarp 60 ft hi.gh with even crest b) 30% vegetation; with grass and small trees in clumps moving downslope; slumped red clay, shallow slides, large rotation slump at base; crest scarp; 55 ft high with even crest c) 90% vegetation with poplar, alder, birch and occasional conifer;. slumped red clay; subdued medium scale slumps and slides; 60 ft high even crest, similar to (a) d) 30-50% vegetation; in clumps of alder and birch moving downslope; slumped red clay with brown streaked clay occasionally exposed at base; medium scale rotational slumps and shallow slides; crest scarp; 60-65' high with even crest e) 90% vegetation with poplar, alder, birch and occasional conifer; slumped.red clay; subdued medium scale slumps and slides; 60-65' high witheven crest f) n-60% vegetation with birch and alder with grass in clumps moving downslope, Horsefls on recent failures; red clay with brown and red clay towards base; shallow slides, bluff height 65-75 ft and constant except where it drops to meet a creek. Toe: a) 50% vegetation with horsetails and clumps of alder, birch and grass; slumped red clay; protected from waves b) 0-10% vegetation; flowing and/or slumping red clay with some brown clay;@toe hit by storm waves, or in places, presently at water level Beach: a) narrows to the east from 50' to 15', sandy with concentration of pebble§'and granules 10' from shore b) 3-15' wide; sandy with scattered pebbles; in places beach consists only of swash zone c) 20-@5b' wide; sandy with pebble concentration 10' from shore 61 120- Profile 36/25- 1 100- ft. to 5 ft. depth so- r-Fz-6.99 W W 60- A LL A-S 100% vegetation 40- rc B-C 305,; vegetation 20- bc mudflows 20 40 60 86 1010 11210 11410 11@0 1" 260 2120 240 260 2@O 120- SF=1.21 Profile 36/25-2 100- ft. to5ft-depth so- A-B 50% vegetation A B-C 30% vegetation W C-D 70% vegetation W 60- LL shallow slides 40- rc bc 20- c D mudflows @O 46 66 @O 100 120 140 1@0 180 26 220 240 , 260 280 120- Profile 36/25-1 100- SF=0.9u ft.to, 5 ft.depth A-B 90% vegetation W Uj 60- LL 40- rc 20- bc 20 40 60 80 100 120 140 160 180 200 220 240 2@O 2;0 FEET F E E T gn C3 Pi al 0 vo ca z 9 63 Section 30, T 49 N R 11 W 4 The section lies immediately east of Poplar River Road in Lakeside Township and is bisected by the Poplar River. Throughout the-section, red clay is a major constituent in the bluff, with 20 ft. brown clay present stratigraphically below the red clays. The brown clay is only observed in the occasional mudflows and slumps at the toe or in ravines. The western portion of the bl uff, is actively failing with small scale slumps and shallow slides. In this subsection, vegetative cover is only 30%, consisting of clumps of birch and alder moving downslope. The bluff is moderately steep (24') increasing nearly vertical just east of the Poplar River. The remainder of the eastern part is better vegetated, up to 70% cover with the slumps and slides more subdued. The toe, comprised of slumped red and brown clay, is protected from wave erosion by a wide sandy beach, except in one or two subsections. Access is fair for the western half but poor for the eastern half, so public use is rather infrequent. 64 SEC30 T49N R11 W SAFETY FACTOR A-less than 1.UO B-1.00 to 1.25 C-greater than 1.25 CONFIDENCE LEVEL A-boreholes (high confidence) B-near boreholes stratigraphy visible C-no stratigraphy visible (low confidence) le 0 In m 0 C4 CO CL r.M D6 65 Sec. 30, T 49 N, R 11 W Bluff: a) 30% vegetation with birch and alder in clumps moving downslope; slumped red clay with some brown clay exposed at base; small scale slumps and shallow slides; bluff height 60-65 ft; vegetation increases and bluff height drops ' at the Poplar River and small creeks; occasional upper part of bluff is well vegetated b) 40-70% vegetation with alder and birch; slumped red clay with brown clay at base; subdued slumps and shallow slides; bluff height even at 60-65' Toe: a) Poorly vegetated; red clay or brown clay; flowing or slumping; waves hit toe during storms b) Moderately vegetated red or brown clay; rounded crests occasionally flowing, toe hit by waves during storms Beach.: a) 30' wide; sand with pebbles at shore b) 3-15' wide; width variable; sandy with pebbles; beach occasionally consists only of swash zone c) 30-50' 'wide; sandy with pebb les at shore; extensive driftwood towards Poplar River d) 10-20' wide; width fairly even; sandy e) 0-15' wide; width variable; sandy with occasional cobbles and numerous slumped trunks 66 120- Prof ile* 3 o - i 100- ft. to 5 1 t.depth so- W A W 60- LL A-B 70ro vegetation B B-C 2M vegetation 40- shallow slides rc 20- hc c 20 40 66 s6 i olo 120 140 160 180 200 220 240 260 2W im- Prof ile'30-2 100- ft. to5ft.depi A-B 95% vecetation 80- R-C 20% vegetation @A ALI 60" W U- shallow slides 40- B rc 20--; br c 20 66 80 100 120 140 160 180 200 220 240 260 280 120- Profile 30-3 100- ft.to 5 ft. dept; so- FF=1.27 W A A-B 100% vegetation W 60- shallow B-C 0% vegetation C-D 10% vegetation slides P-E 50% vegetation 40- D 20- c @sh@a sl lo@@@@ ide Dt .c 20 40 60 80 100 120 140 160 180 200 220 240 260 280 FEET T.49 N.,R. I I W,SOC.30 240- 220- 200- 180 ON 160- 140 ui 120 loo 80 2 3 CL 0 60 rc rc re 40- 20- bc bc bc 1060 2000 3000 4000 5000 F E E T 68 Borehole Site 2 Borehole Site 2 is located in Reach 2. It begins 0.5 miles east of the Poplar River and ends 0.5 miles east of Bardon Creek. The site includes 2.2 miles of shoreline in Sections 29, 28, and 21 of Township 49 north, Range 11 west in Douglas County. This study area is comprised of high bluffs with actively-eroding slopes. The bluffs average 70 feet in height and are dissected by several gullies and streams. Bluffs in Section 29 and the western half of Section 28 are composed of the two clay units identified at Site 1. The lower, browner clay unit is exposed only in the lower 20 feet of the bluff face. Cobbles and boulders eroded-from this unit help to identify its location. A third stratigraphic unit appears in the eastern half of Section 28 and continues into Section 21. It is a well-sorted) dark-brown sandy silt deposit that is exposed in the-lower bluff profile. This unit is very compact, obtaining slope angles as high as 60 degrees (see Profiles 6 and 7). Erosion in the western three-quarters of Section 29 occurs in the form of shallow translational slides and flows. Surface water has played, and is playing,,an important role in erodi7ng these Douglas County bluffs. Cirque- shaped basins are created by drainage patterns which channel surface water across the bluff. As a result, the vegetation on these slopes has been stripped by this active erosion. A distinct change in erosional mode occurs in the eastern quarter of Section 29. Massive rotational slump blocks, sometimes encompassing the entire bluff,.have been observed. The western half of Section 28 appears to be relatively stable since the bluffs remain fully vegetated and there is little evidence of slope failure. East of these stable bluffs, bluff profiles change dramatically. In this area, 69 the bluff toe is composed of the sandy silt overlain by the browner clay. The differential strength of these two soil units has resulted in a distinct break in slope (see Profiles 6 and 7). Erosion of the sandy silt unit occurs in the form of shallow translational slides while the clay unit experience rotational slumping, and flows. Redder clay from previous slumps often covers the lower units. Beaches along Study Area 2 are generally narrow, (averaging 10 to 20 feet), but wider beaches occur near streams.and fullies (see Profile 4). Beaches are often covered by debris from recent slope failures. 70 e 5 4 3 C 00 2 d b 0 C In A SF@@.80 b 0 eq kn 0 A SF=0.97 C 04 a -200 C13 kn @@s F_ 90 B 14 0 0 N S F= 8 77 5 SF= 1.0 B 100 SF=1.57 0 SF= 1.07 2 .100 N 69 If' 72 SAFETY FACTOR (SF) 6 BEACH A-less than I.UO 5 TOE B-1.00 to 1.25 C-greater than 1.25. 4 BLUFF 3 STABILITY LINE CONFIDENCE LEVEL A-at borehOles CONFIDENCE LEVEL (high confidence) SAF.ETY FACTOR 'a-near boreholes with stratigraphy visible C-no stratigraghy APPROXIMATE SCALE visible (low confidence) 1 inch 1500 feet 71 Borehole Site 2 Bluff: a) No vegetation, with shallow slides and flows b) No vegetation, with massive slumping c) Full vegetated, no erosion d) No vegetation, steep slopes greater than 45', with translational slides, and slumping present Toe: .a) Flow and slump debris b) Fully vegetated c) Very steep wave cut toe, sandy silt exposed Beach: a) 0 to 20 feet, sand b) jO to 70 feet, sand c) 10 to 20 feet, sand d) 20 to 50 feet, sand e) 10 to 20 feet, sand 72 T.49N.,Rll W.,SEC 29 100- PROFILE 1 80- vegetation AS - 20% BC - 0 % u' 60- A LU U_ SF= 1.0 T 40- -seeps p,si,C 20- b P,si,c C no beach 0 40 so 120 160 200 100- PROFFILE 2 so - 0% vegetation SF= 1.5 7 uu,j 60- U. 40- p,si,C 20- O,P,s i.c beach -sand 0 40 80 120 160 200 100- PROFILE 3 so- % vegetation SF= 1.0 1 60- p,si,C. 40- 20- bs,p,si,c beach -,.;and 0 40 80 12 C- .160' 200 -seeps psiC iip S,,c@ 73 T.49N.,R11 W.,SEC 28 100- PROFILE 4 S F= IA9 80- 20% vegetation Luj 60- U U_ 40- p.silc 20- beach -sand 0 40 80 120 160 200 100- PROFILE 5 so- A SF=2.00 vegetation AB 10% BC 600% Uw 60- CD - 0% LL p,si,c 40- B 20- C i,c D beach sand 0 40 80 120 160 200 T.49N.,R11 W.,SEC 21 100- PROFILE 6 80- 0% vegetation SF= 0.97 Lu 60- Ui slum U_ p,si,C 40- 20-- bd.p,si beach -sand 0 40 80 120 160 200 y s p 74 T.49N.,Rll W.,SEC 21 100- PROFILE 7 80- 0% vegetation 60- uj U. p,si,c 40- SF= 0.8 0 20- beach -sand 0 40 so 120 160 200 P i'c 's S bd p @s<bei C@ C) C@ tD %D CO CO -J IJ Cr, M Ul Ln LJ W M) CD (@D Ln C) Ln C:o Cjn CD Ln C) Ln C) Ln C) Ln CD Ln C> Ln C) Un C) Ln CD C-" r1t 'D C:) r1l) Go CD- 0 C) W:E --4 CD I -r-0 C)c Ln C-0. C) cn CA CD 'a C@ C* co CA :E: 0 00 (D r%) 2c, rDM 0 rD C+ F- ul C+ (D Ln :E 06 C> r) ai Ln r-n co Lf) Li P. C-) 4- C+ CL 00 OD IM C> C@ CD C:) C) C@ e") Ln E3 N3 LA Ln -2, C) rn a, Q, (1) (D < OL l< 0V) Co C-) UD M 'D -0) M 2. oj < 0- (D CD 0 Ln c+ :3 S L 76 Section 29, T 49 N R 11 W The section lies a half a mile to the east of the Poplar River and is bounded on the east side by Peterson Road. Throughout,the section, the bluff is comprised of red clay, with approximately 20 ft. of brown clay at the-base of the bluff. Thelbrown clay is usually covered and exposed only in ravines. The bluff height is constant at 70-75 feet. Large slump blocks are responsible for moving large masses of material from the bluff. These blocks are now at the toe, actively being eroded by wave action. The exposed bluff face above the slump block exhibits shallow slides and clumps of sod with individua 1 trees moving down slope. No indigenous vegetation has 'been able to establish itself on these slopes. Where large slumps have not occurred, the toe is usually a low rounded step of a former mud flow. In these localities, a wide sandy beach is present. In slumped areas, beach width is highly variable and occasionally consists only of the swash zone. As access is not very good, the section gets little public use. 77 SEC29 T49N R11W SAFETY FACTOR A-less than 1.00 B-1.00 to 1.25 C-greater than 1.25 COMMENCE LEVEL A-boreholes (high confidence) B-near boreholes stratigraphy visible C-no stratigraphy visible (low confidence) V, 0Cq 0 U, 78 Sec. 29, T 49 N, R 11 W BI af f a) upper 2/3 40% vegetation wi.th birch and grass clumps in shallow slides,lower 1/3, 90-100% vegetati.on with birch and alder; large slump block; red clay b) 60-100% vegetation with bArch, alder, and horsetai,ls; red clay; hummocky surface with occasional scarp c) largely unvegetated except for slump b-locks and three clumps; red clay; shallow slides and slumps Toe: a) Low 3-15'; wave eroded, slumped red clay low 3; rounded, protected, slumped red clay c) Low 3-15' scarp of slumped red clay; may be unprotected when beach is absent Beach: a) P-10' wide-, width variable; sandy few pebbles, patches of cobbles, b).15-201 wide; sandy with pebbles hear shore C) 0-15' wide, width variable; sandy with pebbles hear shore d) 15-20"wide; sandy with pebbles near shore 79 120 Prof i le 29 -1 100- ft. to 5 It.depth so- A-B 20% vegetation W B-C 60% vegetation W 60- C-P 1005'o vegetation LL shallow slides 40- slump block 20- C D 20 40 60 80 100 120 140 11@0 W 200 220 240 260 280 Profile 29-2 100- ft. to 5 ft. depth so- A W 60- W A-B 100% vegetation LL B-C 0% vegetation 40- C-D 60% vegetation 20- C .26 4 60 80 100 120 140 160 180 200 220 240 260 280 120- Profile 29-3 100- ft.to 5 ft.depth shallow A slides A-B 0% vegetation W LU 60- B-C 50% vegetation L.L 40- B slump block 20 C 20 40 60 8@ 160 12'0 140 160 1@0 260 2210 240 260 280 FEET F E E T 0. co Co 0 0 C, Q 10 CA 08 81 Section 28/21, T 49 N R 11 W The*section lies to the east of Peterson Road and is bisected by Bardon Creek. De Vries Road runs parallel to the shoreline along the bluff top west of Bardon Creek. Red clay is a major constituent of the bluff. Beneath this material lies 20 feet of brown clay. Toward the western end., a brown silty material appears in a ravine 10 ft. above the lake level. Its upper contact with the brown clay rises to the east until it is 20 ft. above the lake surface. Though covered many places east of Bardon Creek, this silty unit forms a prominent bench in the slope profile as seen in RP 28/21-3. Throughout the section, shallow slides are the dominant form of failure. This material accumulates at the toe to be eroded by waves. Where the silty unit forms.a bench, the sliding material forms chutes, flowing over the bench and fanning outat the base into a lobe. The beach is sandy and of variable width. It widens at the mouth of Bardon Creek and is absent where flows and slides have covered it. Vegetation is very sparse throughout the section and consists only of trees and sod slumped from the crest. A few summer cottages abut DeVries road but none have developed access to the shore. At the end of DeVries, a cottage with several smaller buildingsis present right on the lake. A cement pier and some boulder rip-rap have been constructed here. Public'use is limited by poor access. 82 SEC28/21 T49N R11 W SAFETY FACTOR A-less than 1.00 B-1.00 to 1.25 C-greater than 1.25 CONTFIDENCE LEVFL A-boreholes (high confidence) B-near boreholes stratigraphy visible C-no stratigraphy visible (low confidence) 0 Nrp ON C@ V), 0 0 13 6 N 0 V) 0 21 0 28 83 Sec. 28/21, T 49 N, R 11 w Bluff: a) 90-100% vegetation with birch,.alder, and occasional conifer; red clay over 20' of brown clay; slumps subdued and vegetated with. occasional new,scarps and flows; 65-70' high, even crest b) 30% vegetation with birch and sod in clumps in upper portion and horsetails covering lower slope; red clay over brown clay; small slumps, shallow slides and mudflows; 65-70' with even crest c) 10% vegetation-with occasional birch and sod clumps; red clay over 20' of brown clay over 10' of brown silt; slope very steep with shallow slides and mudflows; W-75' with even crest d) bluff absent- Bardow Creek e) 10% vegetation with sod clumps; red clay 35', over 20' of brown clay over 20' of brown silt; shallow slides and mudflows@; silt forms proninent steep slope; 70-75' high with even crest Toe: a) 3-5-ft;;slumped red clay; horsetails and sod clumps; wave protected b) rounded, un-vegetated, slumped red clay of mudflows; in places hit by wacks c) toe absent-Bardon Creek d) slumped red clay, mudflows, unvegetated, un-protected from waves Beach: a) 20_25'@ wide; sand with scattered pebbles; width constant b) 8-15' wide;sand with scattered pebbles c) 0-8' wide; width variable; sandy with log litter and occasional boulders d) 8-50' wide; widents at mouth of BardonCreek; sandy e) narrow sandy swash zone or.beach absent: scattered driftwood 84 120- Profile 2S/21-1 too- ft. to 5 ft -depth SF=1.020 SF=1.007 Lij A LLJ LL 60- A-B 1001@'. Negetation B B-(-' 609; vegetation 40- rc C-D 8LA; vegetation C 20- - - - bc 20 40 60 so 1@o 12,0 140 160 180 200 220 240 260 280 120- Profilf 28/21-2 100- ft. to 5 ft. dep so- SFMO.951 W _60- 0,01. vegetation Uj LL shallow 40- rc slides 20- C bsi 26 @6 66 80 100 120 140 1iO 200 220 240 260 280 120- Profile 28/21-3 100- ft.to 5 ft.deptl SF-0. 977 so- low LLJ A shallow slicips L,j 60- 05- vege .tation except A-S veoetation rc 40- 20- bc flows bsi 20 40 66 86 -@O 12,0 140 160 1@0 260 2@O 240 2@O 280 FEET T-49 N.,R. I I W,SOC.28/21 240- 220- 200- 180- co Ul 160- 140 120 too u 2 z 3 c 80 60 rc rc rc 40- bc 20 bc bc bsi bi; i. 0 1000 2000 3000 4000 5000 F E E T 86 Section 22, T 49 N R 11 W The section lies 8 miles north of the town of Maple and is bisected by Pearson Creek whose mouth may be reached by Beck's Road. The deposits which make up the bluff are, from the top, 30 ft. of red clay, 20 ft. of brown clay, and 20 ft. of a brown silty material. The clay is fairly uniform whereas the character of the silty unit is variable, ranging from a homogenous sandy silt with occasional pebbles in the western end, to 30 ft. of sand with bands of red clayey sand in the eastern end. The silty unit does not fail readily and has a gulleyed appearance when not covered. It is moderately resistant and forms a steep face as can be seen in RP 22-1 and RP 22-3.. The clays above are occasionally steep slope formers (RP 22-1), but more commonly exhibit shallow slides and flows. Often, where the silty unit is present as a bench, clay material will flow over it., forming a slide chute,.and fan out at the toe. Vegetated sod clumps with trees are also carried over the bench. The bluff face is devoid of any indigneous vegetation, and what little there is consists of clumps of sod with trees that have pulled away from the failing bluff crest. The beach is wide and sandy at the creek mouth where the toe is fairly stable. But in the intervening areas, beach width is variable, narrow, and occasionally absent. The toe is often unprotected and being eroded. Access is good to the west half by Becks Road and the beach is used when present. To the east, the bluff is less accessible because of Pearson Creek. 87 SEC22 T49NRI1 W SAFETY FACTOR A-less than 1.00 B-1.00 to 1.25 C-greater than 1.25 CONFIDENCE LEVFL A-boreholes (high confidence) B-near boreholes stratigraphy visible C-no stratigraphy visible (low confidence) CV kn C1 NrS V V) 0 cc C14 0 N0 9L in WO 22 88 Sec. 22, T 49 14, R 11 W Bluff: a) 10-20% Vegetation, clumps of sod with alder; red clay over brown clay over 20' of brown silt: Shallow slides and mudflows, flows. leave chutes on hillside and lobes at base where they fan out; si.lt forms bench. which may be.obscured; 70-75' hi.gh with even crest b). 30-60% vegetation; small alder and grass in clumps with horsetails predominating on the lower slopes; red clay overlying shallow slides predominate with occasional scarps.; brown silt outcrops but does not influence slope angle: 70-75' high, fai.lry even crest c) 40% vegetation,in upper slope with alder; lo@,!er slope unvegetaied; brown and red clay over brown silt; shallow slides and mudflows; flows leave chutes on slope and lobes at base where they fan out; silt forms bench; 65-70' high d) 30-60% vegetation; horsetails wi.th alder*clumps; shallows sli.des; crest has scarp; does not form bench; red clay over silt 40-45' high with even crest e) 1.0% vegetation,'occasional birch or alder clump; red and brown clay over sand with sandy till intermixed and at base; shallow slides .in clay and eroded face in sand; crest scarp.occasi.onally vegetated; 60! high with fairly even crest Toe:. a) unvegetated protected lobes of redclay that have flowed over silt uni.t b) slump blocks of red clay; vegetated on backs; protected but occasionally unprotected c ) un.vegetated; protected flow lobes.of red clay d) vegetated horsetai.1s;,sl,umped red clay; protected e) unvegetated; protected flow lobes of red clay Beach., a),10-25' wide, sandy with scattered pebbles; occasionally absent due to extensive flows b) 3-8' wide, width variable;.sandy; occasionally absent due to slump blocks and mudflows C) 10-25' wide; sandy, with scattered'pebbles d) 40-50' wide; sandy, cobb.ly in swash zone and 20' back 89 120 Profile 22-1 100- ft. to 5 f I -denth SrU0.965 80- W A -Fk 80-10(r., venetation LLI 60- R-r On venetation LL rc 40-- bc mudf low 20- - bsi C 20 40 60 so 100 120 140 160 180 2;0 220 240 260 280 120- Profile 22-2 100- SFul.008 ft. to5ft.dept,", so- A A-B 40% vegetation LLJ 60- B-C M.veoetation LU 4r rc 40- -slide/flow chute bc 20- mudflow bsi 26 4 66 iO 100 120 44'0 16 180 200 220 240 260 280 120- Profile 22-3 100- ft.to 5 ft-depth SF-0.949 so- (r, venetation LLJ shallow slide Ljj 60- ILL rc 40----- bc 20- S S mmif lows s shallow rc slid @ rc- bc bsi c _ _ <b s 2@ 46 k 86 1@0 120 140 11@0 11@0 2@O 2@O 240 2@O 280 FEET F E E T 0 C) 0 COO vo 01 cr n Ld Pi Pearson Creek -7-@n -r7--7- w 06 91 Borehole Site 3 Borehole Site 3 is located in Reach 2 and extends from west of Haukkala Creek to a point midway between Nelson and Fisher Creeks. This study area includes 2.2 miles of shoreline in Sections 23, 14, and 13 in Township 49 north, Range 11 west in Douglas County. The shoreline is dominated by erodible bluffs which range from 50 to 65 feet in height. Haukkala Creek, Nelson Creek, and three unnamed streams dissect these bluffs. The bluffs at this site have geological units similar to those identified at Site 2 one mile to the west. In the western end of the site, the two clay units are underlain by a unit of well-sorted sand (see Profile 1). Further. to.the east, the lower, browner clay is intermittently exposed at the,.bluff toe. The two-clay units are occasionally separated by a thin lense of sand (see Profile 2). Gray clay, which may represent an inclusion within the silty-clay soils, is present at one location within the study area (see Profile 6). Bluff failures primarily in the form of large-scale rotational slumps result from the continual erosion of the bluff toe (see Profiles 1and 4). Beaches, generally less than 10 feet in width, provide little protection from this wave action. The removal of vegetation by large-scale rotational slumping has increased the susceptibility of the site to translational slides and saturated earth flows., 92 4 0 0 0 rq 5_1 ..ip it V/' 6-93 S-71, SAFETY FACTOR (SF) 6 BEACH A-1 ess-Th-an-T.-U0 B-1.00 to 1.25 .5 TOE C-greater than 1.25 4 BLUFF CONFIDENCE LEVEL 3 STABILITY LINE A-at boreholes 2 ONFIDENCE LEVEL (high confidence) S-near boreholes with SAFETY FACTOR stratigraphy visible C-no stratigraghy visible (low APPROXIMIATE SCALE confidence) I inch 1500 feet 93 Borehole Site 3 Bluff: a) 80% to 100% vegetation except where large scale rotational slumping has occurred, flows and translational slides present locally. Toe: a) Wave cut with local slump blocks and flow terraces Beach: a) 0 to 10 feet, sand; greater than 30 feet near streams, and gullies. 94 T.49N.,R11 W.,SEC23 100 PROFILE 1 so- vegetation AB - 10% SC - 70% Uw 60- CD - 0% LL A 40- P,si,c B large slump 2Q- concealed C s beach. - sand/boulders -1 -120 0 40 80 160 100- PROFILE 2 80- vegetation AB 90% A BC 10% LLU" 60 - LL p,si,c 40- 20- bd,p,si.c C beach -sand 0 40 80 120 160 200 100- PROFILE 3 @0 - vegetation AB 80% BC 0% 60- Uj, A 40- bA,P.Si.c 20- B C beach sand/cobbles 0 40 so 120 160 200 P'si'c - - B large sluml @@,onceale@d C :@s 'p.; D 'si.c c 95 T.49N.,R11 W.,SEC 13 100- PROFILE 4 80- vegetation AB - 20% BC - 80% 60 CD - 0% - Ui A p'si'c B 40- large slump concealed 20- C p S1,C D beach sand/boulders 7 1 1 1 1 1 1 1 0 40 80 120 160 200 100- PROFILE 5 80- vegetation AB 10% BC 50% LwU 60- LL A CD 0% - p,si,c B 40-- concealed slumps, slides 20- C blA,y,si,c D beach - sand/boulders 0 40 so 120 160 200 100- PROFILE 6 80- vegetation AB 0% BC 75% LLU so- .U CD - 0% LL A 40 - p'si'c B slump 20- concealed C seeps --bo, p, r. -si,-c D beach -sand B large slump onceale@d 'p. C D S@ 7c slumps, slides _con@cealed C D d'y's. bd 0 40 80 120 160 200 96 T.49N.,R11 W.,SEC 13 100 PROFILE 7 60- vegetation AB - 0% BC - 100% LU w 60- CD - 0% LL p,si,cA B 40- concealed 20- C D beach -sand bd,p,si.7 0 0 1 0 160 200 _@co n c e a @Ie d C @D@@b e a @ch 97 Section 23/14, T 49 N R 11 W This section is located to the west of Windy Lane, a road which meets Highway 13 one mile west of Cloverland. The section is bisected by Haukkala Creek. In this section, the bluff height slowly decreases steadily from 55 ft. to.45 ft. Similarly, a silty unit, which occurs in the sections to the west, become less visible to the east and is absent by the center of the section. The silty unit here contains a large amount of sand. Failure in this unit j_s uncommon and, when exposed, has an eroded appearance. The overlying 20 ft. of brown clay and 30 ft. of red clay are similar in type of failure. Occasionally, a large rotational slump occurs, but shallow slides are more common. -In the more vegetated reaches, occasional scarps are noticeable, signifying renewed failure. In the western third, vegetation is sparse and consists of horsetails, and trees and grasses being rafted down from the failing crest by shallow slides. In the remainder of the section, though not entirely stable, grass and alder cover 80-90% of the hummocky bluff face. In some subsections the beach is wide and the toe is mostly protected. In the other subsections, the beach width is variable and often absent, leaving the toe unprotected from wave erosion. Access to the shore in the section is poor. No development is present at this time along the bluff. 98 SEC23/14, T49 N R1 I W SAFETY FACTOR A-less than 1.00 B-1.00 to 1.25 C-greater than 1.25 CONFIDENCE LEVEL A-boreholes (high confidence) B-near boreholes stratigraphy visible C-no stratigraphy visible (low Oe confidence) V4, 0 N 0 N L; 14 C4 99 Sec. 23/14, T @49 N, R I I W Bluff: a) 10-20% vegetation with occasional alder or birch clump;,red tobrown clay over sand with till; shallow sli des and mudflows; 55-60 ft high; crest fairly even; sand with till forms bench. b) 10% vegetation; with grass tufts and birch clump; steep failing. slope; red to brown. clay over sand with till; 60-65' high c) 80-90% vegetation; horsetails and alder; hummocky rounded bluff face; clay over sand with till (?); even crest 55-60' d) 50% vegetation with grass birch and 'alder ' red over brown clay: shallow slides with scarps common: 50-55' with even crest Toe: a) unvegetated protected lobes of mudflow red clay that have flowed over sand with till bench b) rounded, slumped red clay, unprotected with occasional tree@clumps Beach: a) 3-8 wide; sandy with cobbles.and boulders; occasionally absent b) 20-30' wide; sandy with scattered pebbles; lots of driftwood c) 3-8' wide; sandy with occasional boulders; occasionally absent d) 20' wide; sandy with pebbles at shore e) 3-8' wide; sandy with occasional boulders, occasionally absent, 100 120- Profile 23/14-1 1100- ff.to5h.deplt SF=1.27 so- lCr!, venetAtion ILJ LLJ 60- U- shallow Slidps and flows 40- r 20- bc -------------- s 20 46 66 86 1700 120 140 160 180 200 220 240 260 280 120--@ Profile 23/14-2 100- ft. to 5ft- der so- A-S 60%, vegetation LLJ R-C 00,; venetation 11.1 60-A shallow slides SP-1.031 LL 40- rc 20- B hallow sliHes bc and flows 26 4 60 80 100 120 140 160 180 26 2@O 40 2' 2'80 2 60 120- Profile 23/14-3 100- ft.to 5 ft.d.ep 80- A-B 905% vegetation LJ SFwl.26 R-C O@;, verjetation Lij 60- LL A small slump scarps 40 rc X 20- shallow slides bc and flows C r bc 20 40 60 80 100 120 MO 160 1@10 2@O 2@O 240 2@O 280 FEET F E E T co Z5 Z CD HAUKKALA CREEK 10 TOT 102 Section 13, T 49 N R 11 W The section is located four miles west of the mouth of the Brule River. The beach is not present throughout the section, being absent or nearly so for about a quarter of a mile in the middle. West of this it begins at 15-20 ft. in width widening to 40 ft. Eastward it reappears at 10-20 ft. for the remainder. When present, it is sandy and boulders are quite frequent throughout. The bluff declines slowly from 50-55 ft. in the west to 30-40 ft. in the east and is moderately to well vegetated throughout. It is failing by two mechanisms. At the west end, repeated shallow sliding predominates, producing an evenly-sloped hummocky surface. At the east end, failure is by large, single-block sliding of moderate depth-, this produces a broadly stepped profile. A long subsection in the middle shows elements of both mechanisms. The bluff is composed of a red clay, mostly slumped, coveting a brown clay which underlies it. The toe is poorly to partially protected on the average and is composed of slumped red clay. Although there is reasonable access to the section, use seems to be limited. 103 SEC 13 T49N R1 1 W SAFETY FACTOR A-less than 1.00 B-1-00 to 1.25 C-greater than 1.25 CONFIDENCE LEVEL A-boreholes (high confidence) B-near boreholes stratigraphy visible C-no stratigraphy visible (low confidence) 0 0N 104 Sec. 13, T 49 N, R 11 W Bluff: a) 50-55.ft; crest scalloped and scarped; shallow sliding slumps;. 70-9.0%,alder and grass silty clay over clay b) absent-estuary C) 50-55 ft; single block slide with shallow failure above'and below; 60/10 alder and grass; slumped silty clay over clay d) 40-50 ft. declining to east; crest scarped and scalloped; poorly expressed single block failure; numerous shallow failures - hummocky; vegetated 40-80% birch, alder and grass, horsetails; silty clay over clay e) 35-40 ft; broadly scalloped; single-block moderately-deep slide, .shallow sliding on main and toe scarps; vegetated 70-90% alder and grass Toe: a) partially protected, slumped silty clay .b) absent-estuary c) protected, rounded slumped silty clay d) poorly protected, slumped silty clay - in situ clay e.) unprotected, slumped silty clay and in.situ clay f) partially protected, silty clay and in situ clay Beach: a) 15-20 ft; discontinuous, coarse sand with boulders offshore b) 40 ft; coarse sand with pebbles boulders at water c) 0-5 ft; coarse sand, boulders offshore under waves d) 15-20 ft, discontinuous; coarse sand,.boulders offshore e) absent-boulders f) 10-15 ft; coarse sand boulders offshore 105 120- Profile 13- 1 100- ft.to5 ft.depth 80- W W 60- numerous shallow A-3 50% vegetation LL slides B-C 3(Wi vegetation 40- 20 20 40 60 80 100 120 140 160 180 200 220 240 260 280 Profile 13-2 120- 100- ft. to 5 ft. depth so- ____-@numerous shallow W 60- slides W LL 40- A-B 70% vegetation B-C 80% vegetation rc C-D 5% vegetation 20 C f I 26 4 60 80 10'0 12'0 140 160 180 200 220 240 260 280 120- Profile 13-3 100- ft.to 5 ft.depth .so- A-B 90% vegetation B-C 100976 vegetation W C-D 10% vegetation W 60- ILL 40- A large slump block B 20- D 20 40 66 810 100 120 140 160 180 200 220 240 260 280 FEET f E T 4@ co CD 0 NELSON CKEEK m ao L% 90T 107 Section 18, T 49 N R 10 W This section is located three miles west of the mouth of the Brule River. There is a beach present along most of the section. To the west it is sandy and discontinuous, 10-20 ft. wide with boulders offshore. It widens to theleast to 60-70 ft. The bluff is 50 ft. high at the west end, drops to 35 toward the middle, and rises to 40-45 ft. at the east end of the section. It is well-vegetated except near the stream mouths, where the bluff is usually much steeper than elsewhere. Failure is by many.processes and is quite varied spatially. It is usually marked by a single slump block 10-20 ft. deep across its top. The slide may be anything from shallow to -moderately deep. The top of the block is frequently hummocky and ponded, and it may be titled forward or backwards. The long scarp above the block may be hummocky and well-vegetated or actively sliding and flowing. The front of the block forms the toe and is usually scarped and failing by sliding and flowing. The bluff is composed of a red clay, which contain a fair amount of silt. A browner clay is occasiona lly exposed near the toe, but the contact is obscured by the failure. The toe is composed mostly of slumped clay and its degree of protection is directly related to the width (or absence) of the beach. There is good access at the west end of the section,.but use appears limited. 108 SEC 18 T49N R10W MUETY FACTOR. A-less than B-1.00 to 1.25 C-greater than 1.2S CONFIDENCE LEVEL A-boreholes (high confidence) B-near boreholes stratigraphy visible %Y C-no stratigraphy visible (low confidence) A CO 00 M 0 M 0 N CT. is 109 Sec. 18, T 49 N, R 10 W Bluff: a) 50 ft at west, dropping to 35 in middle and rising back to 40 ft at east; crest broadly scalloped, both scarped and rounded; failure is by many processes and is quite varied spatially: large rotationa-I slumps, slides and flows on slump scarp; brown silty clay; birch, alder, grass, moss and horsetails. Toe: a) partially protected, but may be either rounded and vegetated or scarped and flowing; slumped silty-clay b) protected, rounded and vegetated but occasionally scarped and flowing; slumped silty-clay c) unprotected, scarped and flowing Beach: 6) 10-20 ft, discontinuous coarse sand with boulders frequent of offshore b) 60-'70'ft; coarse sand with boulders frequent offshore c) absent; boulders offshore 110 120- Prof i le 18 1 100- ft. to 5 f t. depth so- LU LU 60- U. N 40 slump block A-B 80fo vegetation 20- be B 20 40 60 86 1010 120 .140 160 180 200 220 240 260 280 120- Prof i le i a@2 100- ft. to5ft.dept 60- LU shallow slides A-B 90% vegetation 40-. A and flows R-C 40% vegetation 20- - slump block B 1@0 11 7 -- 26 4 so 10'0 1210 140 SO 26 220 240 260 280 120- Profile 18-3 100- ft.to 5 ft.depti so- LU LU 60- U- A-B 90fo vegetation 40- B-C 80% vegetation 20-' slump block allow slides @A @,d f owsslump, block B 20 40 60 80 100 120, 140 160 180 200 2@O 2@O 2@O 2 0 FEET t4 9 N..' R. i oW,Sec.i8 i4O 220- 200- ISO 160- IAO - LU uj 120 - 100 80 2 3' 60 40 rc rc 20 bc bc -r-c- - 0 1000 2000 3000 4000 5000 F E E T 112 Section 17/8, T 49 N R 10 W This section is located 2 miles'west of the mouth of the Brule River. West of Smith Creek the beach is either absent or frequently interrupted. Where present in the se subsection, it is sandy, 10-20 ft. wide with boulders offshore throughout. A 40-60 ft. wide sandy spit is built across the Smith Creek estuary, some of which is vegetated. East of Smith Creek the beach narrows'to 20-30 ft. The bluff is 35-40 ft. high and moderately to well-vegetated throughout. Failure is by shallow sliding with blocks of varying size and number, and by flowing. In the eastern half, there is a single, large block,' and the sliding is perhaps the deepest here. There is additional sliding and flowing above and below this block. Between this.subsection and Smith Creek, the sliding becomes quite shallow and is much mixed with flowing. East of Smith Creek, numerous shallow slides are present above a subdued larger block. The bluff is composed of a red clay, which is underlain by.a brown clay.- The the is unprotected where the beach is absent, partially protected elsewhere; but it is only wbolely protected east of Smith Creek. It is composed of slumped .clay. Access to the section is quite poor. 113 SEC 17/8 T49N R10W SAFETY FACTOR A-less than 1.00 B-1.00 to 1.2S C-greater than 1.2S CONFIDENCE LEVEL A-boreholes (high confidence) B-near boreholes stratigraphy visible C-no stratigraphy 4) visible (low confidence) 0 0 N N W 0 0 N H U) r4 114 Sec. 17/8, T 49 N, R 10 W Bluff: a) 35-40 ft; crest broadly scalloped, scarped or rounded; single moderately deep slide, shallow sliding and flowing on main scarp and.toe; vegetation 70-90%, birch, alder, grass, horsetails; red- .brown silty clay, mostly slumped b) 35-'40 ft. crest scalloped and scarped; shallow sliding and flowing, lacks large single block failure; vegetation 40-60%, alder and grass moving down slope; silty clay C) absent -,Smith Creek; boulders offshore d) 40 ft; crest scalloped, rounded; failing by single block, shallow slide, with sliding and flowing above; vegetation 80-90%, birch, alder, grass, silty clay Toe: a) unprotected, scarped, flowing and sl iding, slumped silty clay b) generally protected, often scarped, flowing and sliding, slumped silty clay. c) absent - Smith Creek; boulders offshore d) protected; slumped silty clay, rounded and vegetated Beach. a) absent,'boulders offshore b) 10-20,ft; coarse sand often interrupted by toe-flo,ws, boulders offshore c) absent - Smith Creek; boulders offshore d) 5-10 ft; coarse sand, 2-3 ft wave-cut face at water-line e) 40-60 ft. back half vegetated; 2-3 ft. wave-cut face 25 ft from water-line; coarse sand with concentration of pebbles near water, boulders f) 20-30 ft; coarse sand occasionally interrupted; concentration of pebbles near water: a-5ft wave-cut face 6-8 ft from toe, boulders @115 120- Profile 17 s-i 100- ft. to 5 ft -depth so- w W 60- U_ 40- A slump block\ A-B 10(Wa vegetation B-C 3(W* vegetation 20- B I)c C 20 60 so 100 120 140 160 180 200 220 240 260 2BO 120- Profile 17/8-2 100- ft. to5ft. depth SF=7-25 so- W 60- W umerous shallow A-B 60% vegetation U. slides and mudflo s 410.m-' 20- 20 40 60 80 100 120 140 1W 11@10 26 2W 240 2W 2W 120- Profile 17/8-3 100- Ift.to 5 f t.dept h so- W Ljj 60- U. shallow,slides 40- A-B 100% vegetation B-C 70% vegetation 20- mp block ume O's @A Slum block p 13\ C @ Ah s allow Iide@sand mud-flo s @@s luml: C T__ 20 40 60 160 1RO 260 2@O 80 100 120 140 240 2@O 280 FEET F E E T Z 540=1i CPFEK 9TT 117 Section 9, T 49 N R 10 14 This section is located j'ust west of the mouth of the Bru-le River. A sandy beach 30 ft. wide, is present along the western half of the shoreline. It then becomes narrower (15-20 ft.) is often interupted and then widens quickly to 80 ft. The bluff is 40 ft. high to the west declining 35 ft. just west of the estuary after which it is absent. Subsections to the east and west ends are moderately to well vegetated and failing such that one large slump block is well preserved. Shallow sliding of much smaller blocks occurs on the scarp above the block while the scarped toe is more prone to flowing. A short subsection toward the midd le is more poorly vegetated and is -failing by numerous shallow slides and flows of small scale. The bluff is composed of a red clay, which is underlain by a browner clay. In places mediu'm-coarse sand interbedded with silts and clays may be found between them. These relationships are partially obscured by the slumps and vegetation. The toe is scarped and composed of slumped and in situ clay along the western three-quarter. The eastern quart,er is well-rounded and vegetated. There is good access to the very small western-most portion of the shore but the estuary is unpassable at present. SEC 9 T49N R10W SAFETY FACTOR A-less than 1.00 B-1.00 to 1.2S C-greater than 1.25 CONrTDENCE LEVEL A-boreholes (high confidence) B-near boreholes stratigraphy visible C-no stratigraphy visible (low confidence) 0 u U3 0 0 N 119 Sec. 9, T 49 N, R 10 W Bluff: a)40ft; crest broadly scalloped, rounded; single-block shallow slide with flowing and shallow sliding on main and toe scarps; 90% vegetated, birch, alder, grass, horsetails; silty clay gradational to clay, with a clean sand occasionally between b)35 ft; crest scalloped, scarped; shallow sliding and flowing; poorly vegetated 0.5% on moving blocks; silty clay over clay, sometimes gradational sometimes with sand in-between c)35 ft; crest broadly scalloped, single-block shallow slide with flowing and shallow sliding on main scarp and most of toe; moderately well vegetated, 50-60% alder, grass, horsetails; silty clay gradational to clay with occasional sand layers. Toe: a)Protected,,flowing, slumped @)poorly Protected, scarped and flowing, slumped silty clay Oprotected, mostly rounded, slumped silty clay Beach: a)30 ft; coarse sand with some pebbles at water; .5.ft. wave-cut face cl*ose to toe; boulders offshore b)discontinuous, interrupted frequently, 10-15 ft. coarse sand with boulders offshore 020-80 ft; broadest just west of stream and across estuary coarse sand with pebbles near water; 2-3 ft wave-cut face often present. 120 120- Prof ile 9--1 100- ft. to 5 ft. depth so- LLI LLJ 60- A-B 90@r, vegetation LL shallow B-C 70'ro vegetation slides C-IN Oao vegetition 40- 20 5 B C flowing 20 40 60 so 100. 120 140 160 180 200 220 240 260 280 120- Profile 9-2 100- ft. to5ft.dept so- W 60- UJI U_ 40- A-B 0-5% vegetation 20- B F 20 46 @O 80 100 120 140 160 180 200 220 240 260 280 120- Profile 9-3 100- ft.to 5 ft. dept I so- il@=! @!)3 shallow slides and flows LIJ 60- LL A-B 4W; vegetation 40- slu p block SF=1.86 B-C 60% vegetation C-.D 0% vegetation 20- rc C --flowing hr r L-7 A k rc 20 40 60 80 100 120 140 160 11@0 260 220 240 260 280 FEET F E E T co cm 0 0 n 10 n (AI LN t 0 'A @j 122 Reach 3 Reach 3 extends approximately 9.5 miles from the Bois Brule River to Quarry Point, one mile west of Port Wing. This reach includes Sections 10, 3, 2, and I of Township 49 North, Range 10 West, in Douglas County, Sections 6, 5, and 4 in Township 49 North, Range 9 West, Sections 33, 34, 35, 36, and 25 in Township 50 North, Range 9 West, and Sections 30 and 19 inTbwnship 50 North, Range 8 West in Bayfield County. Bluffs are generally less than 30 feet high in the reach. Between the Brule and Iron Rivers the redder clay unit composes most of the bluffs. Between the Iron River and Quarry Point a thin cap of the redder clay overlies a sandy loam and/ or lenses of well sorted sand. Bedrock crops out at the toe of the bluff from Jardine Creek eastward. Erosion along this reach of shoreline has become a serious problem at several locations. Shore protection for State Highway 13 has been required at a location 6.5 miles west of Port Wing between Reefer Creek and Iron River. The U.S. Army Corps of Engineers, in cooperation with the Wisconsin Department of Transportation, has established a demonstration site to test low cost structural protection methods. In addition to Highway 13, several homes are being threatened by erosion. Recession rates averaged 1.5 to 2.0 feet per year between 1938 and 1966. Locally, erosion rates have been much higher. Bluff retreat of 27 feet was measured over a 13 month period at the Corps of Engineers demonstration site (Sterrett, 1978). Beaches, where present, are less than 10 feet wide and composed of sand and gravel. These na rrow beaches provide very little protection from wave attack. Erosion of the bluff face is largely the result of shallow slides triggered by oversteepened slopes and saturated earth flows. Very little rotational slumping has been observed within this reach. 123 With the exception of the western two miles of shoreline, part of the Brule River State Forest, all land is under private ownership. State Highway.11provides excellent access-and much of the shoreline has been .subdivided for seasonal and year-round homes. Even though several homes are being threatened by erosion, no privately-owned shore protection structures are found within this reach. 12.4 Section 10/3.'T 49 N,R 10 W The section lies just west of Brule Point in Brule River State Forest The western half is cut by the Brule River and the shoreline characteristics show the river's influence. Access is excellent along Brule River Road. A parking lot with picnic facilities lies at the end of the road near shore, a small park operated by the DNR. There is no bluff along the shore at the eastern end. Here sandy spits have prograded, protecting the bluff and forming a@.marshy area behind. A profile across the'present spit is shown in RP 10/3-1. In the remainder of the section, a very low bluff is present, rarely exceeding 20 ft. The materials in the bluff are dominantly red clay but others are present. Medium to coarse sands occurs below the red c12y in varying thicknesses occasionally comprising much of the bluff. At the toe and lying under the sand (where the sand is present), a brown clay is occasionally exposed, and beneath that in just a few small outcrops is a red sandy,till. The bluff height is low enough that major failures are uncoramon.. Instead, the toe is undercut by wave action and the surface vegetation and sod slowly slide downslope. Wheresand comprises much of the bluff, mass wasting phen*omena are replaced by rill erosion. The beach is variable in width and particle size. It is mostly sandy although certain subsections are bouldery and cobbly. Where the beach is absent, wave action is directly eroding the toe. Because of the good access, this reach is used frequently. Since it is a state'@@forest, no housing development has o'ccured along the bluff crest. 125 SEC 10/3 T49N R10W SAFETY FACTOR A-less than I.UU B-1.00 to 1.25 C-greater than 1.25 CONFIDENCE LEVEL A-boreholes (hig.h confidence) B-near boreholes VO stratigraphy.visible C-no stratigraphy visible (low confidence) 0 0 N NY, 0 0 C4 13 10 126 Sec. 10/3, T 49 N, R 10 W BluM a) No Bluff; sandy spits at shore with marsh behind; stable vegetated slope lies well behind beach b) 100% vegetation with confier and alder; fairly hummocky S-irface with occasional scarp; red clay over red sandy till; 20-25,' high with even crest C) unvegetated except for occasional treeclump; red clay with thick sand in places over red sandy till; shallow slides or eroded; 20' high with even crest 40% vegetated with birch clumps; red clay over till; small slumps and shallow slides; 20' high Toe: a) No Bluff b) Yegetat-dd rounded slump block toe; forms step 2.5' high; unprotected c) occasionally Beach: a) sandy spits; pebble concentration along shore b) 3-8 ft. sandy with scattered boulders; locally beach is cobbly c) 20 ft.; sandy d) 3-8 ft.; sandy with scattered boulders e) 10-20 ft.; sand, boulders, cobbly in places, coarse sand along shore 127 120- Prof ile 10/3-1 100- ft. to 5 ft. dent h 80- l'- LIJ UJI 60- OFS veaetation LL 40- 20- sandy spit f I 20 46 66 80 100 120 140 160 180 200 220 240 260 280 120- Profile 10/3-2 100- ft. to5ft.depth 80- LLI 60- 80ro vegetation UJI LL 40- 20-... shallow slides b bc c 26 4 66 80 100 120 140 180 200 220 240 260 280 120- Profile 10/3-3 100- ft.to 5 ft.depth 80- ui Lij 60-- LL SF-1.390 1005r venetation at crest 40- 0% remainder of profile 20- rr )c r st z -::,Z. _shal 20 40 80 100 120 140 11@0 18'0 200 220 240 2@O 2'80 FEET E E T Co. cc COO RRTYLF Prxyrp 129 Section 2, T 49 N, R 10 W This section is located just west of Brule Point, about one mile east of the Brule River. A sandy beach is present spordically along the shoreline. Subsections of 15-20 ft. in width alternate with subsec- tions of 15-20 ft. in width alternate with subsections of near or total absence. The beach is quite wide just east of the stream estuary which-bisects the section, but it narrows steadily thereafter. The bluff is 15-20 ft. high at the western. end anddeclines slightly to 10-15 ft. at the estuary. Following a subsection of no bluff (graded, gentle slope) it rises again to 10-15 it. and then more slowly to 15-20 ft. It is failing by shallow sliding and flowing; but the degree of. activity, as indicated by the amount of vegetation, varies. Subsections with 80-100% vegetation alternate with subsection having 20-40%. The @luff is composed of clay, mostly slumping. The toe is composed of slumped clay and its degree of protection relates directly to the width (or absence) of the beach. There is reasonable access to the middle of the section by an unimproved dirt road, but use seems to be infrequent. 130 SEC 2 T49N R10 W SAFETY FACTOR A-less than 1.00 B-1.00 to 1.25 C-greater than 1.25 CONFIDENCE LEVEL A-boreholes (high confidence) B-near boreholes stratigraphy visible C-no stratigraphy visible (low confidence) VO A V 0 N ra. 0 N 1 0 us 131 Sec. 2. T 49 N, R 10 W Bluf f a) 15-20 ft; shallow slides; vegetation 80% alder, birch, grass; red clay b) 15-:-20 ft; scarped crest; shallow slides and flows; vegetation 10%, birch clumps; red clay c) 15-20 ft; crest scarped, shallow slides and flows; vegetation 20%, birch and alder clumps; red clay d) 10-15 ft; crest scarped; shallow slides with good blocks; vegetation 60-70%, alder, poplar, grass; red clay e) absent graded slope very low gradient f) rising quickly to'10-15 ft.; s hallow slides with little movement; vegetation 90-100% grass, alder, birch red clay g) 15-20 ft; crest scarped; shallow slides; vegetation 30-50% grass, alder poplar birch; red clay Toe: a) p rotected slumped red clay b) unprotected, slumped red.clay c) mostly protected slumped red clay d) unprotected, slumped red clay e) absent graded slope very low gradient f) mostly protected, slumped red clay g) 0-5 ft mostly absent; coarse sand with scattered pebbles Beach: a) 15-20 ft; coarse and magnetitesand, pebbles at water b) absent c) 10-15 ft; coarse sand with cobbles and boulders scattered d) 0-5 ft;-mostly absent, coarse sand e) 80 ft narrowing esatward to 10 ft; coarse sand with pebbles and cobbles at water f) 5-10'ft. often interrupted; coarse sand with many cobbles throughout 132 0-5 ft. mostly absent; coarse sand with scattered pebbles 133 120- Profile 2-1 100- ft.to5 ft.de pth go- LU LLJ 60- U- 40- minor slump block A-B 309o vegetation B-C 0% vegetation C-D 50% vegetation 20- A SF*=.96 c 20 46 60 so 100 120 140 160 180 200 220 240 260 280 120-@ Profile 2-2 100- ft. to 5 ft. depth so- W 60- W LL. A-B 0% vegetation 40- shallow slides SF*=.75 20- A @20 46 60 80 100 120 140 160 180 200 240 260 280 120- Profile 2 -3 .100- ft.to 5 ft.depth -lop- Ui LIJ 60- U- A-B 100ra vegetation 40- shallow slides 20- SF*=1.10 20 40 60 80 100 120 140 160 180 200 220 240 2@O 280 FEET F E E T 0. M Z X! cc a 0 0 0 0 CA Lft 40 135 Section 1, T 49 N R 10 W This section lies on the eastern side of Brule Point and is the eastern-most section of the shoreline in Douglas County. Th rough- out the section, the bluff materials consist predominantly of red clay. In two isolated locations, a browner clay of similar texture occurs, but does not influence in the vegetation or failure style. In the western part of the'section where vegetative cover is 100%, the bluff is stable and has a smooth, moderately steep profile. Farther east, vegetation decreases and the clay is failing in small rotational slumps and shallow slides. These slides scallop the bluff crest and carry sod clumps and trees down slope. In the eastern-most -portion, the bluff may be unvegetated and very steep with shallow slides and flows. The*crest of the bluff lies 20-30 ft. above the lake and is fairly even, rising steadily towards the east. The toe of the bluff is unvegetated, except for the western portion and the occasional sod clump brought down from the crest. It is composed of slumped red clay. It is protected by a wide sand beach except in a few subsections where waves attack the toe directly. The shoreline, here, is undeveloped and is used seldom. Access is poor and only from unimproved dirt roads which lie in the adjoining sections. 136 SECI T49N RIOW SAFETY rACTOR A-less than 1.00 B-1-00 to 1.25 C-greater than 1.25 CoNiFIDENCE LENTEL A- oreholes (high confidence) B-near boreholes stratigraphy visible C-no stratigraphy visible (1014 confidence) Sle ON C4 T-A 137 Sec. 1, T 49 N, R 10 W Bluf f a) 10% vegetation, sod clumps; shallow slides in red clay; 18 ft. with root-bound crest b) 100% vegetation; grass sod with birches, smooth stable slope in red clay; 20' with even crest C) 10-40% vegetation with sod and birch in clumps; shallow slides with occasional rotational slump; 20-30' high rising steadily to the east d) 0-50%; well Vegetated where small slumps predominate; no vegetation in near vertical scarps; red clay; 20-30' irregular crest. Toe: a) slumped red clay, unvegetated, occasional unprotected b) 1-2' stop of red clay, protected c) unvegetated slumped clay; forms small scarp when occasionally unprotected d) unprotected slumped red clay Beach: a) 3-10 ft.; sand b) 30 ft.; sandy, no pebbles c) '20 ft. sandy d) 0-5 ft, swash zone occasional; sandy e) 20-30.ft., sandy, no pebbles f) 0-10 ft, sandy with occasionally covering slumps 138 120- Prof i le 1-1 100- ft. to 5 ft. dept U.1 LLI 60- LL 109o vec)etation 40- 20-.. allow slides rc 20 46 60 80 100 120 140 160 180 200 220 240 260 280 120- Profile 1-2 100- ft. to 5ft. der 80- LLI 60- 10%/ vegetation LLJ LL SF*-.75 40- shallow slides 20- .66 20 40 80 100 120 140 160 180 200 2@0 240 2@O 280 Profile 1-3 100- ft.to 5 ft.dep so- LIJ SOF -typnetatinn Uj 60- U- SF*-.55 40-! slumn hlock 20- C@ :@@@h-llow slides 20 40 60 so 100 120 140 11@0 180 200 220 2@O 760 280 FEET t 49 N.,' R. I OW,Se c.1 240- 220- 200- 180- 160- 140 uj UA 120 100 so 60 2 3 40- 20 rc rc f 76' 7- rc F 0 1000 2000 3000 4000 5000 F E E T 140 Section 6, T49N, R9W This section is the westernmost section in Bayfield County. the bluff throughout is composed of 15 to 20 feet of red clay over 5 feet or less of brown clay which is exposed occasionally at the toe. This material is failing.in shallow slides and sliding tree clumps producing a hummocky surface. Medium scale rotational slumps occur occasionally. Bluff height is fairly consistent at 30 feet. The amount of vegetative cover increases from 10-30% in the west to 100% in the east and consists primarily of birch and alder with grass. The toe is made of red clay that has, slid*downslope and is protected throughout by a wide (15-30 feet) sandy beach. Access to the shoreline is possible along a dirt.road from highway 13. Though the land surface affronting the lake has been cleared in the past, it.is returning to a natural,state. No homes occur and the shoreline is infrequently used. 141 SEC6 T 49 N 9 W S _E @@E Ty FACTOP 1,00 A less than B-1-00 to 1.25 C-greater tlian 1.25 CONFIDENCE LEVEL (high confidence) B-near bareholes strat! graphy visible C-no stratigraphy visible (low confidence) 0 0 0 N 1u C% M M Co. 142 Sec. 6, T 49 N, R 9 W Bluf f a) 10-30% vegetatated,shallow slides moving sod clumps; red with occasional brown clay at base; 30' high b) 40-80% vegetated, variable types, alder and birch predominate shallow slides and medium scale rotational slumps in red clay; 20-30' high c) 100% vegetated; alder and grass, low sloping hummocky surface in red clay; 30' high Toe: a) slumped red clay, protected b) slumped red clay; occasionally unprotected c) continuation of bluff slope Beach: a) 30' wide; sand with pebbles at shore b) 5@-15' wide, width variable; sand c) 30-40' wide, sand with pebbles at shore 143 120- Prof ile 6 - I 100- tt. to 5 f t. depth so- w W 60- U- 40- 1-hallcyw qlides S 10-20%1'eqetation 20- 20 40 60 so 100 120 140 1@0 I" 2@O 2'20 240 26'0 2@0' 120- Prof i le 6 -2 100- ft. to5ft.depth SO - w 60- w LL 40- 10(r, Vegetation Small slumps 20- r @6 4 66 @O 1@0 140 140 1@0 200 220 240 260 216 120- Prof i le 6- 3 100- ft.to 5 ft.depth so- 100% Vegetation w LLj 60- U- 40- SF=2.87 20- rc Pr 20 40 60 80 100 120 140 1@0 1@0 260 22'0 24'0 2@O 280 FEET F E E T ol 0 a. CD 0 10 Vtv T 145 Section 5, T49N, R9W This section occurs near the western end of Bayfield County and is bisected by Fish Creek. State Highway 13 lies within 1/4 mile throughout the section. The bluff is 25 to 30 feet high and is composed of 15 to 20 feet of red clay over 5 feet of brown clay. The bluff is fairly stable, its rounded, hummocky appearance indicating no major recent movement. Failure has occurred more recently east of Fish Creek where the bluff-top has been cleared near a small cottage. The bluff is well-vegetated throughout with birch and alder forest. The bluff toe is protected by a wide (15-25 feet) sandy beach. At the extreme east end of the section, the Corps of Engineers has levelled the bluff and rip-rapped the toe with a variety of materials (see subsection description) as a shoreline protection demonstration. A dirt road just west of Fish Creek provides access to the shoreline. One cottage is present but shoreline use is minimal. 146 SEC 5 T4 9 N R9 W SAFETY FACTOR A-les@i than 1.00 B-1.00 to 1@25- C-greater than 1.25 CONFIDENCE LEVEL A-borcholes (high confidence) B-near boreholes strati-raphv visible C-no straticgraphy visible (low confidence) V ie cc F4 M "'@encp 42 00 147 Sec. 5, T 49 N, R 9 W Bluff and Toe: a), 100% vegetated in alder and birch forest; smooth to slightly hummocky surface in red clay; fairly stable; 20-25' high of even crest b) no bluff, Fish Creek with low lying lateral terraces c) 100% vegetated in alder and birch forest; hummocky surface with occasional slumps, red clay, 30' high with even crest d) Corps of Engineers rip-rap study; 500' wide; bluff leveled at low slope and the following sequence of materials are found at toe (west to east) Boulders Concrete ribbed blocks Boulders Interlocking cinder blocks Boulders Interlocking cinder blocks Boulders Bolted automobile tires Boulders Fence of I-Beam frame and railroad ties Beach: a) 20-25' wide; sand with pebbles b) 15-20' wide sandy c) 15-20' wide sandy d) 10-15'; sandy, pebbly with cobbles and scattered boulders e) (see bluff subsection 1d') 148 120- Prot i le5 -1 100- ft. to 5 ft. depth go- w W 60- LL 40- SF*-. 77 1000, Vegetation 20- 20 40 60 so 100 120 140 160 180 200 220 240 260 280 120- Profile 5 -2 100- ft. to 5 ft. dept w 60- III -SP-1. 60 LL 80% Vegetation 40- Slump, b ock 20- rc bc - 4 66 80 100 120 140 160 180 2W 220 240 260 280 1207 Profile 5- 3 100- ft.to 5 ft.deptt w Ui 60- U- 40- SF-1.42 100% Vegetation 20- r br. Slumpb c .-@@rc @b r h, 20 40 60 80 100 120 140 1@0 1@0 260 22'0 :@O 2@O 2@O FEET T.49 N. R. 9 W,Ss c.5 240- 220- 200- 180- 160 140 ui ui 120 100 w w te so - u 60 - 2 3 40- 20- rc rc rc 1000 2000 3000 4000 5000 f E E T 150 Section 4, T49N, R9W This section lies 5 miles to the west of Port Wing near the western end of Bayfield County. The bluff is. 20 to 25 feet high and is composed primarily of red clay (15-20 feet) over brown clay (<5 feet). This material is failing in shallow slides and sod clumps moving down slope. Vegetative cover is highly variable, ranging from 0 to 100% depending on the failure activity along a given portion of the shoreline. Vegetat ion consists of birch, alder, shrubs, and grass predominantly. The bluff is protected throughout by a 5 to 25 foot sandy beach. Towards the east end, boulders occur occasionally on the beach. Half of a doz en cottages are located along the bluff-top but use of the shoreline is minimal. The section.is bisected by Reefer Creek and State Highway 13 lies with in 1/4 mile throughout the section. 151 SEC4 T49N R 9W SNFETY FACTOR A-less than 1.00 B-1.00 to 1.2S C-greater than 1.25 CONFIDENCE LEVEL A-boreholes (high confidence) B-near boreholes stratigraphy visible C-no stratigraphy visible (low confidence) 00 0 N N m Ln 152 Sec. 4, T49N, R9W Bluf f & Toe: a) 20-40% vegetated, tree and sod clumps moving down ste ep (60%) slope in red clay; 20-25' high b) No bluff; Reefer Creek c) 0% vegetated; shallow slides in steep red clay with brown clay at base; 20' high d) 100% vegetated; shrubs and birch, shallow slides and small scale rotational slumps; 20' high e) 40-60% vegetated with tree clumps and grass moving downslope, shallow slides, red clay, 20-25' high Beach: a) 20-25 ft.; sand with occasional pebbles b) Reefer Creek;sand spits c) 5-20 ft; sand with occasional boulders 153 120- Profile 4-1 100- ft. to 5 f t. depth so- w W 60- LL 40- SF*=.79 Oq Venetation 5hallo 20- -7@@ %v slides 20 40 60 so 100 120 140 160 180 200 220 240 260 2W 120- Prof i le 4 -2 100- ft. to5ft.depth so- w 60- ILL 40- .1007o Vegetation 20- .26 46 6'0 80 100 120 140 160 180 26 2@O 2@O 2@O 2'80 120- Profile 100- f UO 5 f t.depth so Uj 60- LL 40- 20- @O 4'0 @O 810 1@0 120 140 V;6 11@0 2@O 22'0 2'40 2@O 280 FEET t49N.,R.9 W,Sog.,4 240- 220- 200- ISO Ln 160- IAO 120 100 80 60 CL u (x 2 40- 14 20- rc T ;7 1@7-c t 0 1000 2000 3000 4000 5000 F E E T 155 Section 33, T 40 N, R 9 W This section lies 5 miles west of Port Wing near the west end-of Bayfield County. The section is bounded on the east by the Iron River. The bluff is 15 to 20 feet high and is composed mostly of red clay. The stiffer and slightly more silty brownclay, which is present to the west of this section, is absent here. Also, bedrock, which is Precambrian red sandstone of the Bayfield Group and absent to the west, is present for the first time in this section. Medium scale rotational slumps and shallow slides are the predominant failure type. Vegetative cover is variable depending on failure activity and includes birch, fir, and grass. A wide beach (20 to, 40 feet) occurs at the east end of the section but elsewhere the.beach is either narrow, absent, or replaced by bedrock. Thus, in places, wav@s freely attack the bluff toe. The shoreline is accessible.at its eastern end from State Highway 13 but is probably rarely used. 156 SEC 33 T 50 N 9 W SAFETY FACTOR --X--Iess than 1.00 D-Loo to 1.25 C-greater than 1.25 CONMENCE LML (Ugh eQnf stratigraphy vi,@ ti>lo C-no stratigraphy visible (low e0afidence) *OL 157 Sec. 33, T50N, R9W Bluff & Toe: a) 80-100% vegetated, birch and firs; Medium scale rotational slumps in red clay over 1-10' feet of red clayey sand; high with even crest;-bedrock at toe in west half. b) 10% vegetated, birch clumps sliding downslope; shallow slides in shallow slides in red clay-Vith bedrock occasionally at toe; 20' high c) 40-50%@vegetated, birch and sod clumps; small slumps; no bedrock at toe; 15-20' high tapering off to east Beach: a) 0-10 ft; sandy with boulders; boulder concentration increases to the east b) 0-5 ft.; cobbly and bouldery; beach often replaced by bedrock V-5' exposed c) 20-40 ft, widening towards east and Iron River; sand with pebbles; no bedrock 158 120- Profile 33- 1 100- It. to 5 It. depth go- W W 60- LL 40- 2(ro Vegetation chall7ow slides 20- rd 20 40 66 100 120 140 160 180 .200 220 240 260 2W 120- Profile33 -2 100- ft. to 5 ft. dept so- W 60- W LL 40-. SF=.92 Shallow sl -ides 0% Vegetation 2C@- r 26 46 66 96 1@0 120 140 '11@0 11@0 200 220 240 260 280 120- Prof i le 100- 1 Lto 5 f t.. dept V so- W W 60- LL 40- 20- 20 40 60 so 100 120 140 160 180 200 220 240 260 280 FEET t5ON.,R.9 W,S@C,33 240- 220- 200- 180- 160- 140 - uj 120 - 100 - so - 60 2 40- 20- 0 1000 2000 3000 4000 5000 F E E T 160 Section 34, T50N, R9W This section lies 4 miles to the west of Port Wing, Wisconsin and the Iron River flows into Lake Superior at its west end. The stratigraphy is more complex here than to the west. Throughout the section, red clay occurs at the top of bluff and makes up the whole bluff towards the western end. In the middle portion of the section, two-thirds of the bluff is made fap of sand with occasional interbeds of red clay. This unit forms a pronounced break in slope. At the extreme easternend, a red sandy-loam till occurs cropping out at the bluff toe. The bluff height is 20 to 35 feet rising steadily to the east. Failure is primarily by small slumps and shallow slides which carry clumps of sod downslope. Vegetation is sparse consisting of birch and grass in the western end.. Towards the east, vegetation is absent except for occasional sod clumps. The beach is narrow and sandy with cobbles and boulders. The width is not sufficient to protect the bluff from wave attack during intense storms. The entire section shows signs of past or present development. Numerous access roads and homesites have been constructed, but the shoreline itself probably sees little concentrated use. 161 SEC34 T 50 N A 9 W SAFETY FACTOR A-less than 1.00 B-1.00 to 1.25 C-greater than 1.25 CONFIDENCE LEVEL A-boreholes (high confidence) B-near boreholes stratigraphy visible C-no stratigraphy Visible (low confidence) 0 0 00 ty"L. tL 162 Sec. 34, T50N, R9W Bluff and Toe: a) No:bluff, Iron River b) 40% vegetated; birch and grass; red clay; small slumps and shallow slides; 20' high C) 40% vegetated grass; red clay over 2 ft. of clayey sand till; long narrow shallow sod blocks sliding downslope; 20-25' high d) 0% vegetated, occasional tree clumps in east end where crestis vegetated; red clay over sand; shallow slides and flows; 30-55' high, sand forms break in slope Beach: a) Iron River; 50' sand beach to west, cobbly swash zone to cast b) 15'-20 ft., occasionally absent; sandy with cobbles and scattered boulders immediately off shore c) 5-10 ft., sand and cobbles with boulders 163 120- Profile 3A -I 100- ft. to 5 ft. depth so- W W 60- LL A-B 105; Vegetation 40- SF=I. 17 B-C IO(Y-.: Vegetation C-D M Vegetation clump block 20- rc 20 40 60 so 100 120 140 11@0 IiO 200 220 240 26'0 2W Prof ile 3A -2 100- ft. to 5 ft. depth so- W 60- W LL 40- !zF*=.96 20- allow slumps 20% Vegetation rc 26 4 66 8'0 100 120 140 160 180 200 220 240 260 280 120- Profile 34-3 100- ft.to 5 ft. depth so- Uj 60- 40- .;F*-.95 20- C-hallow flows slides W/C @rc- 210 410 60 80 100 120 140 160 11@0 26o 2@o 240 2@O 280 FEET F E E T cm 00 CDP CD IPON RIVER fn z 10 ffi; 4;p tA V9T 165 Section 35, T50N, R9W This section lies three miles west of Port Wing and one mile east of the Iron River. Jardine Creek and a small restaurant (the Quarry Inn) are located near the eastern end of this section. The stritigraphy consists of red clay over red sandy-loam till throughout the entire length of the shoreline. At the eastern end, bedrock outcrops at the bluff toe. Above the bedrock lies a zone of breccia composed of broken-up sandstone presumably as a result of fracturing by overriding ice. Bluff height is even at 20 feet. Erosion of the bluff is by rill and wave erosion w/small shallow slides. No large scale failures were observed. The bluff is unvegetated except for occasional clumps of sod moving downslope. Boulders, eroded from the sandy till, dot the predominantly sandy, narrowbeach. The bluff top is fairly well developed for Lake Superior with several cottages, a restaurant, and a wayside off of State Highway 13. Access to the beach is easily made from any of these sites. 166 SEC35 T50N R9 W SAFETY FACTOR A-less than 1.00 B-1.00 to 1.25 C-greater than 1.25 CONFIDENCE LEVEL A-boreholes (high confidence) B-near boreholes stratigraphy visible C-no stratigraphy visible (low confidence) WO, IS N 0 N u in CL IC 167 Sec. 35, T 50 N, R 9 14 Bluff and Toe: a) 0-20% vegetated, sod and birch clumps, red clay over red sand till; till forms a break in slope; 20-30 feet. b) Jardine Creek, no bluff c) 0% vegetated red clay, sandy till, disturbed bedrock over bedrock rilled with slides; 20' high; > 100% slopes Beach: a) 15 ft.; sandy with occasional boulders b) 5 ft; cobbly and sandy with occasionalboulders c) Jardine Creek d) 10 ft; cobbles and boulders 168 120- Profile 35 - I 100- ft. to 5 ft. depth go- Lij LLJ 60- U. 40- FF-.=.65 (rc) 0% Vegetation 20- Shallow slid(-s rd - r-F*=1.03(rst) 20 40 60 80 100 120 140 160 180 200 220 240 26'0 2E6 120- Prof i le 35 -2 100- ft. to5ft.depth so- W 60- LU LL .40- I;F* 0% Vegetation -.63 (rc) 20- rc'*'-. shallow slides rst SF*-1.0(rst) 20 60 80 100 120 140 11@0 1@0 200 220 240, 2@O 2iO A20- Prof He 35 -3 100- ft.to 5 ft.depth so- W LLJ 60 - LL 40- SF*=.48(rc) -,F-c.76 (rst) 0% Vegetation 20 20 40 60 86 10'0 120 140 160 180 200 2iO 240 2@O 28'o FEET. 169 120 Profile 35 - 4 100- ft. to 5 ft -depth 80- LU LJJ 6o- LL 40- cF*=.43(rc) 05% Vegetation SF*=.68(rst) SF"-=. 68 s) 20- -..rc cqbr 20 40 60 So 100 120 140 160 180 200 220 240 260 280 120- Profile 100- ft. to 5 f t. depth so- uj 60- LLI LL 40- 20- 46 @D 80 100 120 140 160 180 200 22D 240 260 280 120- Profile 100- ft.to 5 ft.depth so- LLJ LLj 60- U_ 40- 20- 20 40 60 so 100 120 140 160 ISO 200 220 240 2@O 280 FEET F E E T co 0 0 0 0 Q C3. JAPDINF CPFFK 14,-, CL (7 OLT 171 Section 36/25, T50N,R9W This section lies two miles west of Port Wing. The stratigraphy throughout is highly variable with several units. Red clay occurs at the bluff top through the entire section. In the western third, this red clay overlies a red sandy-loam till which in turn overlies bedrock. Occasionally the bedrock has a brecciated appearance. Red clay over bedrock dominates the middle third. Here bedrock composes one-half to two- thirds of the entire bluff. The remaining eastern third has red clay over bedded sand and gravel with bedrock occurring occasionally at the toe. The bluff varies in height from 20 to 35 feet. Vegetation'is sparse with the exception of occasional sod clumps that have moved downslope. Erosion is primarily by rilling and wave action with shallow slides. Little development has occured along the bluff top with the exception of a few cottages. Access to the beach is from Kukor Road located at the eastern end of the section. 172 sEC36/25 T50N R9w' @gr@,Ty YACTI.IR 1.00 ._less th n B-1,00 to 1.25 C-greater than 1.25 90 CONTIDENTCE LEVFL --'@o (high corif idence) a04 B-near borehales stratigraDhy visible C-no Stratigraphy visible (Im'T confidence) 0 0 u 173 Sec. 36/25, T 50 N, R 9 W Bluff and Toe: a) 0-20% vegetation, birch clumps; red clay over disturbed bedrock occasional cobbly sandy till; eroded with clay flows; bedrock in toe and occasional wave beaten; 20-25 ft, b) 0% vegetation; red clay over bedrock; 20' with Bedrock up to 15' c) 0-10% vegetat 'ion, tree clumps; red clay over find sand and gravel; rilled with shallow flows.; 20-30' high Beach: a) 5-20'; cobbly with occasional sandy streatches and scattered bedrock outcrops b)'bedrock with occasional small sand pockets c) 20-30'; sand and pebbles with scattered boulders and cobbles d) 5'; cobbles and boulders 174 120- Prof i le 36/25 --1 100- ft. to 5 it. depth so- LLI LLI 60- LL 40- 0% Vecetation *-.!56(rc) 20- .*-.79(br) rc", d @Iucl f 10,ms h-r- 20 40 60 86 100 120 140 160 180 200 220 240 260 280 .120- Profile 36;25-2 too- ft. to 5 ft. depth so- LLJ 60- LLI LL cF=1.20 0% Vegetation SF=1.71 40- M d flows .s -T- 20 46 a6 80 100 120 140 160 180 200 220 240 260 280 120- Profile 100- ft.to 5 ft.depth so- F- uj Uj 60- LL 40- 20- tzr d@ r h-r- KLF 270 M d 20 40 60 so 100 120 140 160 180 200 220 240 2@O 2iO FEET T.5 0 N., R. 9 W,50 C. 36/25 240- 220- 200- 180- F- Ln 160- 140 LU uj 120 100 so 60 2 40- 20 rc rc sp dbr hr ---- - -- I T- I 0 1000 2000 3000 4000 3000 FE E T 176 Section 30/19, T50N, R8W_ This section lies just one mile west of Port Wing. Quarry Point, the site of an abandoned sandstone quarry, occurs at the east end of the section. The entire shoreline in this section is-dominated by bedrock. Locally sand and gravel may overlie the bedrock,and red clay occurs at the top of the bluff throughout. The bluff height is 20 to 30 feet high with bedrock making up one-to two-thirds. Rilling and some mudflows occur in the red clay but the protection of the bluff by the bedrock toe allows the unconsolidated portion of the bluff to become somewhat stabilized. Beaches are present only in bedrock.recesses. Vegetation is 10 to 20% with shrubs and occasional tree clumps. Several summer homes have been built along Kukor Road in the western half of the section. The eastern half is largely undeveloped. Access to the shoreline is eassy along Kuk.or Road and at Quarry Point. 177 SEC30/19 T50N R8W 0 ,e SAFETY FACTOR A-less than 1.00 D-l.oo to 1.25 C-greater than 1.25 Co\,T- IDENCE LEVEL -boreholes C)KI (high confidence) B-near boreholes stratigraphy visible C-no stratigraphy visible (low confidence) N N 178 Sec. 30/19, T 50 N, R 8 W Bluff and Toe: a) 10-20% vegetation, shrubs in ravines and occasional tree clumps; shallow slides and rilling; red clay over sand with gravel lenses; bedrock occasionally at toe and hit by waves; bluff steep 25-30' high b) bedrock domi.nated bluff with up to 10' of unconsolidated material (red clay and/or sand with gravel) resting on 5-15' of exposed bedrock; 20' high with little vegetation Beach: a) 5-25'; sandy and cobby wi.th scattered boulders and occasional bedrock b) bedrock at water level with occasional cobbly pocket beaches 179 120- Prof i le 30/29 - 1 ft. to 5 ft -depth too- 80- LLJ LLJ 60- Or/' venetation LL SP*-.52(.rc) SF*-.57(so) 40- rc 20 rilled so slides 20 46 60 so 100 120 140 160 180 200 220 240 260 280 120- Profile 30/29 -2 100- ft. to 5 ft. depth so- SF=1.249 Lij 60- 10% venetation LU U- 40- 20- r rilled rs br @6 40 66 So 100 120 140 160 180 2W 220 240 2@O 22 0 120- Prof i le 100- f t. to 5 f t. dept h so- F- LLj 60- LL 40- 20- 4@ 80 .100 120 140 11@0 11@0 2@O 22'0 240 2@O 280 FEET F E E T co 0 0 0 CS) 08T 181 Reach 4 Reach 4 starts at Quarry Point one mile west of Port Wing and extends 7 miles eastward to a sands tone outcrop one mile west of the Village of Herbster. This reach includes Sections 11, 12, 14, 15, 19, 20, 21, and 22 of Township 50 North, Range 8 West, and Sections 6 and 7 of Township 50 North, Range 7 West in Bayfield County. The geology of the shoreline changes significantly within this reach. A two-mile sand spit is found along the western edge of Reach 4. This sand spit forms a bar around the mouth of the Flag River. Bluffs reoccur west of the sand spit and gradually rise to a height of nearly two hundred feet. The bluffs are primarily composed of sand and gravel, and capped with a discontinuous layer of clay-loam. Sandstone bedrock is exposed at the bluff toe at several locations. Beaches between Quarry Point and the Flag River are sandy and narrow. East of the Flag River the beaches are sandy and very wide near the harbor jetties, and decrease in width towards the east. Beaches along the bluffs are generally less than 10 feet in width and composed of cobbles and boulders. Where sandstone is exposed at the base of these bluffs, no beach is present. Erosion rates along this shoreline vary significantly. Between Quarry Point and the jetties at the mouth ofIthe Flag River, recession rates in excess of 20 feet per 'year have been measured. East of the jetties the beach has accreted as much as 12 feet per year. This variation is caused by the jetties which block the westerly littoral transport of sediment, thereby starving beaches to the west and creating a surplus of sand on the eastern 182 side of the jetties. Along the high bluffs, erosion is very spotty. Approximately one-half of the bluffs are well vegetated and show little active erosion while other portions are void of vegetation and actively receding. Erosion of the bluffs occurs in the form of translational slides and flows. No large-scale rotational slump blocks are present along this shoreline. Where bedrock is exposed at the base of the bluffs, the toe is protected from wave action and little or no erosion is present. The land within this reach is entirely under private ownership. Access to the shoreline is impossible along the high bluff shoreline. The upland areas are undeveloped with the exception of a few year-round residences. Excellent-access is available at Port Wing and a small boat harbor is located at the mouth of the Flag River. Between Quarry Point and the Flag River the shoreline is undeveloped. East of the river to the high-bluff shoreline, a moderate amount of development has occurred, including several seasonal and year-round homes. The only shore protection structures along this reach are the steel-sbeet jetties at the mouth of the Flag River. 183 Section 20, T50N, R8W This section is located just west of Port Wing. Except for a low, wave-attacked bedrock bluff (10 ft. high) at the extreme western end of the section, the shoreline is a 15 ft. wide, medium sand beach. The active beach is backed by a 50-ft. wide zone of vegetated beach ridge and the Bihor, Lake marsh. The harbor of Port Wing i's partially within this section and there is access to the beach at the western end. BVC2() 1 50 ta y l.00 j,@less to j..25 1.25 than reater T C()N rehojes e) nf ide tic high CO 1,01.es D-riear bove , Islb]Le :rrap Y stratIg tgraphY C-no stra (low Visible nce) Conf 3-de 0' CIA Sec. 20/29, T 50 N, R 8 W Bluff: a) Low bench of red sandstone, 10' high and wave attacked b) no bluff Beach: a) beach absent b) wide beach; 15' with steep sand berm, with 50' of grass backed by trees behind beach. Breakwater and light at eastern end for Port Wing Harbor 186 120- Prof i 14 20 -1 100- ft. to 5 t I -depth 80- LU LU 60- LL L 40- 0% Vegetation 20- -FF-c3.4 Medium sand beach 20 40 4@1 80 100, 120 140 160 180 200 220 240 260 2W 120- Prof i le 100_, ft. to5ft-depth so- w 60- w LL 40- 20- @6 26 60 W 100 120 140 1@0 1@0 2W 220 240 260 280 120- Prof i le lw_ ft.to 5 ft. depth LIJ LU 60- LL 40- 20- 20 40 60 so 100 120 140 4D 18'0 200 220 240 260 280 FEET T-5 ON., R. 8 W, So c, 20 240- 220-- 200- ISO- co 160- 140 uj LU Lb 120 100 80- 60 @-A 40- 20 0 1000 2000 3000 4000 5000 F E E T 188 Section 21, T50N, R8W This section is located just east of Port Wing. The shoreline is characterized solely by a beach ridge, backed by a marsh, The unvege- tated (active) beach is 15 ft. wide and composed of medium to coarse sand. The harbor at Port Wing is partially within this section. 189 SEC21 T 50 N R8W SAFETY FACTOR A-less than 1.00 B-1.00 to 1.25 C-greater than 1.25 CONFIDENCE LEVEL A-boreholes high confidence) B-near boreholes stratigraphy visible C-no stratigraphy visible (low confidence) CY 190 Sec. 21, T50N, R8W Beach: a) 15 ft; no bluff;,long sandy beach; backed by grass bordering marsh 191 120- Profile 21-1 100- ft.to5ft-depth so- LU LU 60- LL 40- 0% Vegetation 20- FFjk=4. 2 5 Medium sand beach 20 40 60 80 100 120 140 11@0 18'0 200 220 2410 260 .280 120- Profile 100- ft. to 5 ft. depth so-;. .w 60- w U- 40- 20- 26 4 66 80 100 M 140 160 180 200 220 240 261D 280 120- Profile 100- ft.to 5 ft.depth so- Ui W 60- .U- 40- 20- 20 40 60 80 1160 11210 14'0 160 180 260 22'0 240 260 280 FEET F E E T 0. a co Ol C> a C> a a 0 a bw co 0 40 Z6T 193 Section 22/15, T50N, R8W Section 22/15 lies immediately to the east of Port Wing. Marked changes in stratigraphy and bluff characteristics from those seen to the west occur in this section. The bluff rises abruptly from a 5 feet beach ridge at the section's western end to 60 feet after one-quarter mile. By the east end of the section the bluff height has reached 80 feet. The bluff is capped with a sandy clay to clay loam unit 3 to 5 feet thick. 'Most of the material found in the bluff beneath this clay consists of sand with occasional gravel lenses. Towards the eastern end, medium thick beds of sandy clay occur'within the sand, and usually have seeps associated with them. Most of the bluff is stable and well forested. Large seep failures occur at acouple locations. Much of the bluff is protected from wave action by a sandy, cobbly beach although during storms, waves probably attack the toe. This section contains four private homesties, but most of the shoreline is undeveloped and largely inaccessible. 194 SEC 22/15 T.50N n8W FAOT'IR 8APTY s n A -Jestha 1.00 B-1-00 to 1.25 C-greater than 1.25 CONTIDEN'CEF LMTL C -Y--bo-reQes (high confidencfa) B-near boreholes stratigraphy visible C-no stratigraphy L! 0 visible (low confidence) 195 Sec. 22, T 50 N, R 8 W Bluff and Toe: a) no bluff b) 100% forested in fir and birch; rises to 30' steadily eastward; stable slope in sand and gravel c) bluff is sand and gravel cut by ravines and seep failures with debris slides which form fans at toe; rilling, gullying, and sand flows -on none-vegetated bluff face; bluff alternates 100% forested with 0 vegetation; 60 ft with irregular crest d) 100% forested, fir and. pine, smooth slope in sand and gravel; 60' high e) sand and gravel with occasional indurated sand layers with seeps; 80' high; patchy exposures; 100% forested otherwise Beach.: a) 15 ft sandy, pebbles at shore b) 10 ft cobbles with sand at shore and more cobbles immediately. of shore C) 20';sandy, pebbles at shore d) 20'; even width; cobbles e) 5'; cobbles with numerous: slumped trees 196 120 Profile 22/15-1 100- ft. to 5 ft,depth SF= 1 .044 ui smooth slopp Lij 60- LL 100% venetatinn 40- so 20- T 20 40 60 116 10,0 120 140 16TO 18'0 260 220 240 260 280 120- Prof i le 22/15 100- ft. to 5 ft depth 80- SF=1.057 F- w smooth slope w 60 - 601.", venetation LL 40- sq 20- small slide rsc 26 4 66 @O 10,0 120 140 160 180 200 220 240 260 280 120- Protile 100- ft.to 5 ft.depth so- --Pm- F- w LLj 60- LL . 40- 20- "C' ,\\s C, V 5@mooth <slope rsc 40 60 80 100 120 140 1@0 18,0 2,00 220 240 260 280 FEET 197 120- Profile 22/15-3 100- SFmO.996 ft. to 5 ft -depth 80- Uj LIJ 64D - rills debris/ LL 0% vpnotation rsc 40---- SO 20 - 9- f low _T 20 40 60 s6 11010 120 14'0 160 180 700 220 240 260 280 120- Profile 22/ 15-4 1007 SF=0.974 ft. to 5 ft. depth 100% veqetation so-_ LLJ 60- S W, vegetation except LL) W/C where noted U_ C 40- 20- d fan sg 210 @D 80 100 120 140 11@0 180 26 2@O 240 2@O 280 120-, Pro file 100- ft.to 5 ft.depth so- LU W 60- ILL 40- 20- S @ C S C_ snd fan f 20 40 60 so 100 120 140 11@0 1;0 260 22'0 2@O 2@O 280 FEET F E E T a@ COO COO co INN 86-1 199 Borehole Site 4 Borehole Site 4 is located within Reach 4 and begins 1.9 miles east of the Port Wing harbor. This study area includes 2.1 miles of shoreline in Sections 15, 14 and 11 of Township 50-north, Range 8 west in Bayfield County. It is a high bluff area with bluffs ranging from 60 to 120 feet. The face of the bluffs have been dissected by numerous gullies and intermittent streams which gives the bluff face a 11flat iron" appearance. The composition of the bluffs in this study area are much different than those to the west. Bluffs are composed predominantly of well-sorted. sand and gravel. Clay-loam (less than 10.feet thick). caps the sand in some locations. Precambrian sandstone is exposed at the bluff toe in the northeast portion of Section 15, the southwest portion of Section 14 and the northeast end of the study area in Section 11. Beaches along this coast are generally less than 20 feet wide and composed of cobble t,o boulder-sized clasts. Where b-edrock.is exposed at the bluff toe the beach is often absent (see Profile 3)-. Althrough translational slides are the primary mechanism of erosion, sheetwash and rill erosion are also evident in this study area. The aerial distribution of erosion is very irregular. Bluffs which are actively eroding and void*of vegetation are often adjacent bluffs which are fully vegetated on slopes greater than 45 degrees (Profile 2). This pattern does not appear to be modified by the presence of bedrock at the bluff toe. This pattern appears to indicate that bluff failures are not initiated by wave attack at the bluff toe, but erosional agents acting on the upper half. 200 d d 4 3 c c 0 W1 b b in -70 V 0 8:4 0 N 74 5 2. SAFETY FACTOR (SF) 6 BEACH A-less than--I--.-UO B-1.00 to 1.25 5 TOE C-greater than 1.25.. 4 BLUFF CONFIDENCE LEVEL 3 STABILITY LINE A-a" boreholes 2 CONFIDENCE LEVEL (high confidence) S-near boreholes with SAFEY FACTOR stratigraphy visible C-no stratigraghy visible (low APPROXIMATE SCALE confidence) I inch 1500 feet 201 Borehole Site 4 Bluf f a) Steep slopes, greater than 45*. Vegetation generally restricted to ravines, translational slides present. b) Bedrock, well vegetated c) Steep slopes. Vegetation limited to ravines, gullying and translational slides present. d) Bedrock, well vegetated Toe: a) Wave cut exposing bluff material. b) Generally fully vegetated with sandstone exposed c) Wave cut exposing bluff material d) Fully vegetated with sandstone bedrock exposed Beach: a) 15 to 20 feet, cobbles and boulders, wider near gullies. b) 0 to 10 feet, cobbles, boulders, and/or bedrock. c) 10 to 20 feet, cobbles and boulders, wider near gullies. d) 0 to 10'feet, cobbles, boulders, and/or bedrock. 202 T-50N.,R 8 W.,SEC15 100- PROFILE 1 80- 01% vegetation ui 60 - bd,p.s uj 40 9 20- S/g beach cobbles 0 40 80 120 160 200 100- PROFILE 2 80 - A vegetation md.p,s B AB - 0% u' 60- BC - 100% LU U- CD - 0% 40- concealed 20- C S D beach cobbles 0 40 80 120 160 200 100- PROFILE 3 0% vegetation P,si,c Lu 60- ui LL bd.p,s 40-- s 20 - ss no beach c pls@ S "p' B _7conc@ealed- C S D bd.P S -Ss-- 0 40 80 120 160 200 203 T.50N.,RS W-,SEC 11 100 P,si,c PROFILE 4 80 0% vegetation bkl.P,s seeps U"J' 60 40 20 beach cobbles/boulders 0 40 80 120. 160 200 204 Section 1.4/11, T50N, R8W The section lies three miles west of the town of Herbster. Most of the bluff in this section consists of sand with gravel. But the stratigraphy may be complicated locally by lenses of red sandy clay which are not vertic ally or laterally extensive. The bluff rises steadily to the east from 75 ft. to 140 ft. interrupted occasionally by small creeks entering the lake. Where the bluff is nonvegetated, shallow sand flows-and rills develop. However, most of the bluff is well vegetated in forest. Occasionally, seep failures occur producing long narrow gullies and sand fans at their base. Seeps are usually associated with the clayier beds within the sand. Beaches Are narrow and cobbly, widening where the bluff faces more northeasterly. During intense storms, waves attack the bluff toe directly. The beach and the land along the bluff top is totally undeveloped. The steepness and height of the bluff discourage use of the shoreline in this section. 205 SEC 14/11 T50 N R 8 W SAFETY FACTOR A-less than 1.00 B-1-00 to 1.2S C-greater than 1-25 CONFIDENCE LEVEL A-boreholes (high confidence) 00 B-near boreholes juraphy visible strat C-no stratigraphy visible (low confidence) 0 in C; 0 0 on 11 ON (L . (1.0 0 CII 206 Sec. 14/11 T 50 @N, R 8 W Bluff: a) bluff mostly forested with scattered patches of non-vegetated bluff face; sand with discontinuous silty or clayey beds which are often indurated With seeps; shallow sand flows and rills on exposed face. Occasional seep failures producing long narrow gullies with fans at base; 75-80' high with irregular crest b) 100% Vegetated, fdrested; few scarps, smooth slope; sand with some gravel and occasional clay layers in upper slope which produces seeps, 100' high c) 0-100% vegetated sand with red clay at top of bluff and occasional gra@vel lenses; rilling, gulling and seep failures where non-vegetated; steep 125 -140 ft seeps where sand is silty or clayey Toe: a) sand fans below failures; vegetated, bedrock at extreme W end b) sand.fans c) sand fads below failures; "talus" of slid sand; vegetated Beach: a) 5-10'; cobbles with sand; o ccasional covered by sand fan; numerous slumped trees b) 20-25; sand with cobbles; sand spits at creek c) 10-15 ft; sand and cobbles; sand at creeks 207 120-- Profile 14/11-1 100- It. to 5 f t. depth so- SF=0.976 w w 60-' c A-B; C-D 100c'@ veaetation U_ all other slopes unvenetated 40- s seeps 20- S --,sand fan 20 40 60 ;70 160 1210 11410 '16'0 18'0 200 220 240 260 2W 120- Prof ile 14/11-2 100- SF-0.987 ft. to5ft depth so- rilled c w 60- 0% vegetation w LL -seeps 40- s c3ullied 20- and fan 20 40 60 so 100 120 140 160 180 26 2@O 240 2@O 2iO sc 120 eer) S .,F=0.953 Profile 14/11-3 100- ft.to 5 ft.depth W/g illed -s- /si A A-B SOF vegetation w B-C 100% venetation W 607 LL s gullie 40 B 20- asnd fan rs d 210 410 610 116 1;0 12'0 14'0 1 180 200 220 240 2@O 2'80 FEET F E E T 0 rn co 80Z 209 Section 12, T50N, R8W This section is located 2 miles west of Herbster. The bluff is 140 ft. high at the western end of the section and the height decreases gradually to 120 ft. at the eastern end. The bluff is cut by a number of very large gulley systems, but all of the streams are intermittent. The bluff is composed almost entirely of sand and gravel with a thin, discontinuous cap of clay loam. In addition to rilling and gulleying, seep failures are common and act to keep the gulleys from stabilizing. Except for the active gulleys, the bluff is generally well-vegetated. At the shoreline, cobbly beaches with a coarse sand matrix, 20-40 ft. wide, alternate with bedrock outcrops 4-8 ft. high. 210 SEC12 T50N R 8 W SAFETY FACTOR A-less than 1.00 B-1.00 to 1.2S C-greater than 1.25 -CONFIDENCE LEVEL A-boreholes (high confidence) B-near boreholes stratigraphy visible C-no stratigraphy visible (low confidence) 00 V 0 0 C,4 0 CII 0 0 in 0 0 211 Sec. 12,1750N, R8W Bluff: a) 140-150 ft; sand and gravel; seeping and rilling/gulleying; vegetation variable 0-100%, -tall birch, alder, fir and thick undergrowth b) 140-150 ft; sand with occasional gravel lenses; narrow seep failures which open up laterally at creast; vegetated 60-100% tall birch, fir and alder, thick undergrowth c) 120-130 ft; sand; seeping;.rilling; dry flows; vegetation mostly 0% some 50-90% tall birch, cedar and fir with undergrowth d) 140 ft dropping at strea-n,then rising, as a series of ridges .oblique to shoreline, -to 120-140 ft.; sand with gravel lenses; gulleying and dry flows; vegetation mostly 100% tall birchi cedar and fir;'some 10-20% vegetated slum blocks Toe: a-) vegetated sand b) partially vegetated and partially failing sand c) 6-8 ft bedrock d) vegetated sand, partially failing e) 4-6 f.t.bedrock f) vegetated sand,partially failing g) 4-6 ft and up to 25 ft of bedrock h), vegetated sand, partially-failing Beach: a) 20-30 ft; cobbles and boulders with coarse sand matrix b) 20-40 ft; coarse sand with cobbles atAoe C) 20-5 ft; cobbles with pebbles and boulders d) bedrock with occasional 0-10 ft coarse sand e) 20-30 ft; cobbles and boulders with coarse sand matrix f) bedrock g) ?0-30 ft; cobbles and boulder's with coarse and matrix 212 cont'd. h) bedrock i) 15-20 ft; coarse sand with cobbles at toe .213 Profile 12-1 180- ft. to 5 ft. deg.'.' 160- SF=0.930 X s 120- seep s 100-- seep so- sq /slump block LLI 60- LLJ LL 20- 5 @O 1@0 120 1@0 160 180 26 220 240 -1 @O @D 260 280 200- Profile 12-2 180- f It. to 5 f t. dept h. 160- AIBM- 140- SF=1.072 A 120- A-B partly vegetated 100- so - - - - - - - - - LLI LLj 60- LL 40- 20- B -p Sseep @O 1@0 0 2@O 280 26 40 60 80 100 120 11@0 1 @260 220 24 CY 214 Profit(- il-I 180- ft. to5ft.dep. 160- 140- 120- SF=0.947 100- A-B crest, 0% vegetation so C-D 301,; vegetation W 60- W LL so 40- -seep C 20- D flowed sand -T- - v I - I I I 1 -1 1 1 1 20 @O 66 60 100 120 140 160 180 200 220 240 260 28G 200- Profile )so- f t.to 5 f t.dept! 160- )40- 120- 100- go- W W 60- LL 40- 20- So p C 20 46 60 80 100 120 140 16'0 11@0 26o 21o 240 2@O 2'80 F E E T rp w tr fA STZ 216 Section 7/6, T50N, 97W This section is,located a mile west of Herbster. The bluff height rises from 120 ft. at the western end to 170-180 ft., which is the bluff height of most of the western half of the section. As the shoreline bends northward, the bluff height decreases to 70 ft., which is the bluff height for the eastern half of the section. The higher bluff is composed almost ent irely of sand with a thin discontinuous cap of clay loam. Bedrock occurs occasionally at the toe. Bedrock comprises. the.lower half of the 70 ft. bluff with sand making up the rest. At the very eastern end the bluff is composed of clay loam over silt loam over sand. Most of the failure is by rilling and gulleying with some shallow sliding. The bluff is moderately to well vegetated. In the western end of the section, the beach alternates between 15-20 ft. of coarse sand and bedrock outcrops. The beach of the eastern half of the section is.all bedrock.except the very eastern end which is 45-60.ft. of coarse sand and granules. 217 SEC7/6 150N R7W SAFETY rACTOR A-loss thaii 1.00 B-1.00 to 1.25 C-greater than 1.25 CONFIDENCE LEVEL A-boreholes (high confidence) B-near boreholes stratigraphy visible C-po stratigraphy visible (low confidence) 7ATut ON V Nor 0 in Lr 218 Sec. 7/6, T 50 N, R 7 W B.1 uf f: a) 180 ft dropping to 100 after northward bend; sand with gravel lenses; rilling and gulleying; vegetation as little as 0-10%; half to two- thirds i.s 70-90% tall birch and cedar with undergrowth b) 100 then 70 ft after eastward bend; sand and gravel over bedrock the latter is 1/2 of bluff height; there are watercourses graded to rock lip;occasi.onal fai-lure by block fall; vegetation 100% birch, cedar, fir, alder alonj Eke top o@ ±ke btLJN. c) 70 ft; bedded sands and silts; shallow sliding and gulleying; 40-70% vegetated; clumps moving downslope, birch and alder Toe: a) 15-18 ft bedrock b.) sa ndiprotected c) 15-18 ft bedrock d) sandjp@otected e) sandipoorly protected f) 4-40 ft bedrock g) sand;protected Beach: a) bedrock b) 15-20 ft; coarse sand wi.th occasional cobbles and pebbles c) b.edrock d) 20-25 ft; coarse sand e) 1-2 ft; cobbles and boulders; bedrock just underwater f) bedrock g) 45-60 ft; coarse sand, pebbles at shore, granules in swash zone 219 k SF=1.0,19,, Profile 7/6-1 180-A ft. to 5 ft. de@,, r S 160- 140- 120- A-S 0-1(r- vpqetation R-C 40-5015 w-getAtion 100- Ft ri 1 led so- /Seep w 60- LL c 20- s 26 46 60 so 100 120 140 160 1@0 200 220 24'0 260 280 200- Profile 7/6-2 180- ft.to 5 ft.depth 160- 140- 120- some vegetation at toe 100- SF=0.966 go- s w Ljj 60- r. 40- 20- - 7:7-e p 220 240 2;0 2@O 20 40 60 80 100 120 140 160 180 200 97 1= 9: T F E E T co a LA rn Lt. 221 Reach 5 Reach 5 extends from a sandstone outcrop one mile west of the Village of Herbster along 7 miles of shoreline to the mouth of Bark River. This reach includes Sections 6, 5, 4 and 1 of Township 50 North, Range 7 West and Sections 33, 34, 27, 26, 23, 24, 25, 36, and 36 of Township 51 North, Range 7 West in Bayfield County. The morphology of the shoreline is very similar to that of Reach 3. The bluff at the western end of the reach is 70 feet in height and decreases in height toward "he Cranberry River at which point a low, sandy spit is present. East of the river, the bluffline rises to an elevation in excess of 150 feet halfway between Herbster and Bark Point. Bluff heights then decrease from this maximum to 15 feet along thelneck of Bark Point. The high bluff areas are composed largely of sand and gravel with a thin veneer of clay-loam near the bluff top. The low bluffs near Herbster and Bark Point are primarily composed*of clay-loam overlying a sandy-loam. Precambrian sandstone bedrock is present at the tip of Bark Point. Beaches vary greatly in width and composition throughout the reach. At the mouth of the Cranberry River in Herbster, a sandy beach in excess of 50 feet is present while along the bedrock shorelines no beach exists. Most of the shoreline has a very narrow beach, often less than 10 feet wide, composed of gravel to cobble-sized clasts. The spit and beach at the mouth of Bark River are also wider than 50 ft. Erosion is a serious problem along much of this shoreline. In the Village of Herbster, the low clay bluff is being eroded at a rate of 1 to 2.feet per year. A section of the road along the water front has recently been relocated, and sever al other portions of the road are presently being threatened. The high bluffs east of Herbster ate eroding at 222 approximately the same rate as the low bluff. To date, bluff erosion has not.caused serious problems since very little development has occurred along the bluff edge. However, severe surfac e water erosion in the form of gullying is threatening both homes and roads. Sand and gravel, the principal bluff constituents, are extremely susceptible to stream erosion. Because the clay loam which is found near the surface ,has very low permeability, erosion from surface water runoff remains a continual problem. In addition, some land development activities have served to heighten erosion potential along high blufflines. The combination of rapid runoff, a steep gradient to the lake, the erodibility of the sand and gravel, and man's activities have produced dramatic problems. For example, along the Bark Point Road, severalvery large gullies, some threatening the road have developed as a result of surface water channeliza- tion. Ekcept'in the Village of Herbster where the Town of Clover maintains a lake front park and the mouth of the Cranberry River which is owned by the State of Wisconsin, the shoreline is under private ownership.; This reach of shoreline is moderately well developed. Seasonal and year-round homes are numerous from Herbster to Bark River. Only two shore protection structures are present: a non-functionaltimber jetty at the mouth of the Cranberry River and a timber pier groin which is in excellent condition in front of-a resort in the Village of Herbster. 223 Section.8/5, T50N, R7W This section is located at the town of Herbster and is bisected by the Cranberry River. The bluff is 55-60 ft. high at the western end of the section and becomes steadily lower eastward until it is replaced by a beach ridge, which extends to the eastern end of the section. The bluff is composed primarily of sand and has a thin capping of clay loam. The western end of the bluff is well-vegetated and fails by dry flows and gulleying. The lower bluffs (less than 25 ft.) are less vegetated and shallow slides occur frequently. The beach is uniformly 20-30 ft. wide and is composed of coarse sand and granules, probably derived from the bluff. The beach to the east of the Cranberry River is heavily used by the resi- dents of Herbster and tourists. 224 SEC 8/5 T50 N R 7 W SAFETY FACTOR A-less tftan 1_00 B-1.00 to 1.2S C-greater than 1.2S CONFIDENCE LEVEL @-@or@ehole@s (high confidence) B-near boreholes stratigraphy visible C-no stratigraphy visible (low confidence) 0 C13 '0 C13 0 N Go C% .op 225 Sec. 8/5, T 50 N, R 7 W Bluff: a) 55-60 ft height drops to 30-35 at east end; sand, some clayey sand; gulleying and flowing; 80-100% vegetated birch, alder, cedar b) 25-30 ft - dropping to 0 ft eastward; clayey sand over sand; shallow sliding; 20% vegetated c) absent Toe: a) protected sand b) protected clayey sand c) absent; or beach sands as ridge; xxxxrip-rap Beach: a) 20-30 ft; coarse sand; pebbles at shore, granules in swash zone 226 120- Profile 8/!5-1 100- ft. to 5 f tdepth so- w W 60- LL SF-0.956 A-H O@@ veoptatinn 40 - B-C grass s r x 20- s 20 40 60 s6 1 oo 12'o 14'0 160 180 200 220 240 260 280 120- Profile 8/5 -2 100- ft. to5ft-deptl so- F- w 60- w U- 40- SF*=3.8 A-Ti 1005r vegetation 20- spit A IR f 26 46 @O 80 100 120 140 11@0 1@0 200 220 240 260 280 120- Profile 8/5-3 100- ft.to 5 ft.depth so- w W 60- LL - 40- A-R 1000-" vegetation SFO-2.1 R-C 9011@ veqetation 20- road P ` S T 26 4'0 @O 80 100 120 14'0 1@0 18,0 200 220 2@O 260 280 FEET F E E T 0 rn z CPANBFRPY PIVFP 6D Z7. Ll L Z Z 228 Section 4/33, T50/51N, R7W The western end of this section represents the eastern limits of the Village of Herbster, Wisconsin. The bulk of the material in the bluff is made up of.sand with gravel. The coarseness of this material varies along the shoreline. At the top of the bluffs lies a persistant red clay to clay loam unit. Translocation of clays from this unit has produced a clayey sand unit immediately below-the upper capping unit. Towards the middle of the section, a brown silt-rich, till-like material occurs for a couple tenths of a mile in the bluff. The bluff height is greatest towards the middle of the section where it is 50 ft. The.bluff drops steadily to 25 ft. at.the eastern end. At the western end, the bluff is absent for 1/4 mile. Here, a sand berm, which has been rip-rapped, protects a local roal from wave attack. Vegetation is up to 10.0% and consists of birch, pine and shrubs. Where vegetation is more patchy, rilling and gulleying is eroded the exposed material. The beach is cobbly and narrow throughout and does not serve to protect the bluff toe from wave attack during intense storms. Homesites occur continually along the bluff and a few include access to the beach by stairs. Most use is limited to the easily accessible., sandy beach which lies at the western end of the section. Here the presence of the town of Herbster, a camping area, and a small resort encourage use of the beach 229 7 Sol SEC4/33 T51/50 R7W V 11nig B-1.00 to 1.2s C-agreater than 1-25 CONFIDENCE LEVFL A-borehoIUS (high confi(lence) B-near boreholes Ily visible strati,-,rL'P C-no stratigraphY visible Clotq confidence) 0 u 230 Sec. 4/33, T 50/51 N, R 7 W Bluff: a) no bluff; small rip-rapped 2-4' rise behind beach, vegetation with grass and shrubs b) bluff rises eastward to 40-ft, 100% birches and pines with shrubs in clay over clayey sand over sand and gravel, occasional shallow slides, brown sandy silt occurs at toe over limited beach c) 25-.35' bluff in sandy clay (5-8') over sand with gravel; 80% vegetated, trees; eroding by slope wash and occasional shallow flows Toe: a) no bluff, occasional rip-rap; protected b) vegetated, protected c) vegetated, protected some talus cones of swamped debris Beach: a) 20' wide; sandy with occasional culvert; two piers b) 15' wide; cobbles and pebbles with scattered boulders, c) 5' wide; cobbles of scattered boulders d) 10-20 wide; cobbles and pebbles; occasional boulders 231 120- Profile 4/3.3-1 100- ft. to 5 ft. clopth so- W W 60- LL 40- 20- -rap 20 46 60 80 100 120 140 1610 180 200 220 240 260 280 120- Profile 4/33-2 100- ft. to5ft.deptl, so- SFmO.987 W 60- W LL rc 30@7 veaptation at toe of slope; elsewhere unvegetated 40- -shallow slides rc and rilling sg sand flow 20 66 196 100 120 140 160 180 2@O 2@O 24'0 26'0 28'0 120- Prof i le 4/33-3 100- ft.to, 5 ft.depth so- SF=1.140 W Lj 60- 60Y> vegetation at toe; elsewhere LL rc unvegetated 40-<@ rc :.-rillino w/small slides 20- s -sh nd 20 40 60 80 1@0 12'0 140 160 180 200 22'0 24'0 2@O 2@O FEET 232 120- Profile 4/3.1-4 100- ft. to 5 fdepth 80- LLI 60 - LL 40- SF-0.96 05' vegetation 20- s a fan 20 40 60 86 o'O 1210 140 160 180 200 220 240 260 2W .120- Prof He too- ft. to 5 It depth so- LU 60- w U- 40- 20-. 80 100 120 140 160 180 280 26 46 66 2;0 2@O 240 2@O 120- Prof i le 100- ft.to 5 ft.depth so- LIJ LL, 60- LL 40- 20" S 20 40 60 80 100 120 140 11@0 180 .200 220 240 2@O 28'0 F E E T F E E T co co C@ C> C> C3, 40 rro r" -4 ti 10 n UZ 234 Borehole Site 5 Borehole Site 5 is located half-way.between the Village of Herbster and Bark Point in Reach 5. This study area begins 1.2 miles east of the Village of Herbster and includes 2.0 miles of shoreline in Sections 33, 34,and 27 of Township 51 north, Range 7 west in Bayfield County. The shoreline is composed of bluffs which generally increase in height from 25 feet in the southwest to 85 feet in the northeast. Beaches fronting these bluffs are.10 to 30 feet wide and composed of cobbles. Some isolated "pocket" sand beaches are also found in Reach 5. Bluff composition is similar to that of Site 4, mostly well sorted sand and gravel. Sand'As well compacted and obtain slope angles in excess of 50' in many l6cations. Red-brown clay-loam is found overlying the sand discontinuously. In Profile 6, a stony silt-loam unit is exposed at the toe of the bluff. Sandstone is exposed at one location between Profiles 6 and 7 in Section 27. Erosion along this coast occurs as the result of direct wave attack on the bluff toe. These slopes fail by translational slides and flows. A second form of coastal erosion at this site is gullying. Numerous ravines dissect the bluff face and are actively being enlarged by @surface water drainage. One gully north of Profile 4 is being enlarged at a rapid rate as the result of land management practices. A roadside ditch is channeling large volumes of storm water into the gully which, in turn, erodes bluff soils. .Without some corrective measures, the road may become endangered over the next three years. 235 d 6 4 c 3 2 b In b kn S F= SF= 1. 11 SF=0.99 1z SF= 0:9 Q A 0 SF=1.00 0 700 SFzo.91 IN 1550 SF=0.94 -t- AL T .51 N tr 50 N il SAFETY FACTOR (SF) 6 BEACH A - I e S s--t h a n -1 , UD B-1.00 to 1.25 5 TOE C-greater than 1.25 4 BLUFF C014FIDENCE LEVEL 3 STABILITY LINE ,4-at borehoFe-s 2 CONFIDENCE LEVEL (high confidence) 3-near bor-eholes'with SAFETY FACTOR stratigraphy visible C-no stratigragby. visible (low APPROXIMATE SCALE confidence) 1 inch 1500 feet 236 Borehole Site 5 Bluff- a) 25% to 40% vegetated with shallow slumping, translational slides, and seeps present. b) Steep slopes greater than 450; zero vegetation, translational slides, and gullying present. c) 50% vegetation generally near gullies; translational slides, gullying, and seeps present. Toe: a) Covered with debris from slope failure. b) Steep faced wave cuts exposing bluff material. c) Covered with debris from slope failure. Beach: a) 10 to 20 feet, cobbles and boulders, wider near gullies. b) 20 to 30 feet, sand and gravel. 237 T.51 N..R 7 W-SEC33/34 50 - PROFILE I 40 - 0% vegetation Lu 30 w U- 0.94 20 - L .id.y,s seeps s beach cobbles 0 20 40 60, 80 100 50 PROFILE 2 40- SFz 0.91 0% vegetation U.J 30 - si,c w U- 20- bd,y.s/g,s beach cobbles/boulders 0 20 40 60 80 100 50- PROFILE 3 40- 0% vegetation SFz 1.00 *Ltj 30- LL 's 2r 10- beach cobbles/ bou Id ers 0 20 .40 60 810 100 y r 's ss e @ep s SFz 0-91 s ic ,\bdy @s/gs 238 go - T.-51 N.,R 7 W.,SLC 27 80 - 4 70- 0% vegetation Six SF= 0.93 60 bd,p,s LU 50 U- 40 S?g 30- 26 - bd,p,s 10- beach cobbles/boulders 0 20 40 60 80 100 90 80.- PROFILE 5 0% vegetation 70- 60- SF= 0.99 W 50- LU Six U- 40- 30 bd.Y,S/si 20- 10- beach - cobbles/boulders 0- 20 40 60 80 100 239 90 T.51N.,R 7 W.,SE.C27 80- PROFILE 6 0% veqetation 60- 50- SF=1.55 40 30- A.Y's seeps 2 \0 p,sf 10- beach cobbles % I 1 1. T_ o 20 40 60 80 100 so- 0- p.s PROFILE 7 0% vegetation 7 s SF= 1.11 60- bd.p@s ul 50-- seeps uj - si,c- 40- S 30- 20- 10- beach -rand 0 20 40 so 80 100 7 @O- r"3 C) C:) kD ':3 CO J C7% C7% VI Lrl A@ r@ L.3 E.J N3 f@) CD CD Ln (@n C:) Ln L@ ._n CZ) L" C@ Lrj CD L, C:) Ln Lrj C:) LrI C+ _0 C) C)0 C) wX C) C> =3 Ln C+ C@l- Ln W, :z ;10 C) C+ co 4A C) -V 0 Lo C) -4 CD -0 I.- rD to C+ 0 0 a7r 4@- @ a(D rl,)rD c+ Ln C+ CD (D C) Ln r%@. C_n to CK CD 0 23 rQ r1a rQ r1a Q. r) C) C) C) C) r+ aj Lo M C) C) C:) 00 Lo lc;k rD to C) C) C:) C@ 0 Qj 0 ol m ;@ =5 . = CD C) l< P- f.5L ILnD co - -1 - -% 0 LA M r+l CD -3 C@ Ln L-o @.,, j,' cr C) 0 --1 0- C. :3 L/) =3 cr -V rD 0 17 z 241 Section 34/27, T51N, RN This section lies alcng the western side and forming the base of Bark Point. Herbster lies just one mile to the west. The bluff materials are made up of predominately sand with gravel. At the top of the bluff, a sandy clay to clayey sand unit occurs throughout the section. The sand in places is poorly sorted and contains enough clay that when dry, forms nearly vertical cliffs. Eros.ion occurs in these reaches primarily by slope wash. Elsewhere, sand anddebris flows, block falls, and/or rilling occurs. The bluff rises evenly from 25 ft. at its western end to 60 ft. near the eastern end. At the eastern section line, the bluff top rises sharply to nearly 120 ft. 'The bluff is 80-100% vegetated except for occasional exposures and the stretch towards the western end of nearly vertical cliffs. The beach is.narrow and cobbly and does not protect the toe of the bluff during intense storms. Bedrock is exposed in a very limited expo sure toward the eastern end. The bluff top is partially developed with occasional small cottages or farm buildings. Access to the beach is poor and-evidence suggests that it is used seldom. 242 SEC 34/27 T51N R7W SAFFTY FACTOR --@@--less than 1.00 B-1.00 to 1.25 C-greater than 1.25 CONFIDENCE LEVEL A-boreholes (high confidence) B-near bareholes stratigraphy visible C-no strati-raphy visible (low NXS confidence) 1-0 cc 0 0 Lr 0 0 243 Sec. 34/27, T 51 N, R 7 W Bluff: a) 25-40' high bluff; red clayey sand with clay on top and occasional clean sand beds throughout; 60-80% in birch and shrubs; occasional shallow slides b) steep (45'-90') slopes in hard dry poorly sorted sand; eroded by slope wash, occasional debris flow, and block falls; usually 3-4, of sandy clay at top with overhanging poor bound crest. Farther east, seep failures occur; 40-50' high c) steep high bluff in sand and clayey sand; sandy clay occasionally at crest; 60' high; Densely vegetated on scarp and in ravines but no vegetation on scarp faces; shallow sand flows and rilling Toe: a) occasiona.1 unprotected toe; well vegetated occasional with small fans of slumped material b) sand-talus and flow fans; protected and sparsely vegetated c) too occasionally unprotected; flow fans Beach: a) 0-5 ft wide; sand over cobbles; numerous slumped trees; occasionally absent b) 10-20 ft; cobbles with sand and scattered boulders C) .3-10 ft; variable, sandy and cobbly; numerous fallen trees 244 120- Profile 34/27-1 ft. to 5 ft - dopth 100- 80- LIJ LLJ 60- SF-0.913 %cgetat.ioll LL 40- rcs "r i I led 20- s n fan 20 40 60 80 100 120 140 160 180 200 220 240 260 2@O 120- Profile 34/27-2 ft. to5ft-dePth 100- so- SFWO.p96 LIJ 60- 0% vegetation W s 40--- r i I led 20- S W/g 26 4 66 80 100 120 140 .160 180 200 220 240 2@O 280 120- Profile 34/27-3 ft.to 5 ft.depth 100- so- Spul.008 uj Uj 60- I ". rcs M.venetation U- rilled w/shallow flows 40- S W/d 20- f Pkn W/ n 26 46 66 80 100 120 140 1@0 1. @O 260 22'0 240 260 280 FEET t 51 N., R. 7 W,Sec.34127 240- 220- 200- 180- 160- 140 - ui 120 100 80 2 3 60 1-7@ cs rcs 40- @C- s tw/g 20- sq W/g s 0 1000 2000 3000 4000 5000 F E E T 246 Section 26. T51N, R7W (Northeast-facing) This section is located at the base of Bark Point, approximately 3 miles from Herbster. The bluff is 125 ft. high at the western end of the section, rises to 140 ft., and then decreases steadily to around 10-15 ft. The higher bluffs are composed mostly of sand, with some silty layers, capped by a thin clay loam. A stony silt loam is exposed at the toe at the western end of the section. These higher bluffs are moderately to well vegetated with mature alder, birch, fir, and cedar. Failure is largely shallow slides with some rilling and gulleying. The low bluffs are composed of clay loam over a discontinuous laminated clay over sandyloam. The bluff face is fairly steep and fails in shallow slides and flows. The beach is 15-25 ft. wide at the western end and is composed of coarse sand, probably derived from the bluff. Eastward, the beach thins becomes more cobbly and eventually pinches out. There are a number of cottages on top of the higher bluffs but the beach appears to be seldom used. 247 SEC 26 T 51 N R7W Ob. SAFETY FACTOR --K--less than I.UU 0 B-1.00 to 1.25 C-greater than 1.25 CONFIDENCE LEVEL VO A-boreholes (high confidence) B-near boreholes stratigraphy visible ,C-no stratigraphy 0 visible (10W confidence) in in C@ m 0 N kn C; N r-4 248 Section 26/23, T 51 N, R 7 W northwest-facing shoreline Bluff: a) 125-140 ft. falling to'100 ft "eastward"; some shallow slump and surface flows, rilling and gulleying; vegetation - usually 90-100% alder fir and cedar; where failing, 0-20%; loose sand over silt loam b) 100 ft. falling to 15 ft steadily; shallow slides and surface flows and gulleying; vegetation usually 40-50% alder,,birch, fir and cedar; often 1-00% or 0%; clay loam over sand c) 15-10 ft. even height; shallow slides; vegetation 30-40% as above; clay loam over discontinuous laminated clay over loamy sand Toe: a) protected sand or sandy clay; mostly in situ b) unprotected clayey sand, in situ BeaGh: a) 15-25 ft; coarse sand, with pebbles at.water and cobbles at toe occasionally b) 15 ft cobbles and boulders With coarse sand at water occasionally c) 0-2,ft; cobbles and coarse sand; mostly absent 249 A SFwO. 004 120- s Profile 26-1 B 0 1 0- ft.lo5ft.depth, so- LLj s UJ 60- A-B M venetation LL B-C 1005". venetation C-r, 5-10% vegetation D-E 20@1 vec 40- )etation 20- sc 60 s6 '0 6 20 46 100 120 140 16 111@0 2@O 220 240 2 0 2W 120- Profile 26-2 100- ft. to 5 ft. depth so- SF=1.055 LLJ 60- z LU X U- @\Isc \ A-B 0% veget ation 40- s 20- 80 100 120 140 160 180 200 220 2' 210 @O 60 40 2@O 280 120- Profile 26-3 100- ft.to 5 ft.depth so- LLJ LLj 60- U- 40- A-B I".. vegetation 20- SF*-1.14 D sc c @20 46 60 80 100 120 140 11@0 11@0 260 2@O 2@O 2@O 280 FEET F E E T co 0 00 a C> 0 0 LA ca 40 K:1 "I', F()w Osz 251 Section 24/25, T51N, R7W This section forms the bulk of Bark Point. The bluff ranges from 10-15 ft. to as high as 30 ft. with the greater heights occurring around the tip of the point. The lower bluffs along either side of the point are composed of clay over clayey sand; around the end of the point, bedrock rises to form the toe of the bluff. The bluff face is typically steep and failure is by rill-wash and shallow sliding. The beach ranges from 5 to 20 ft. in width and is often interrupted by'slide debris. The beach is composed predominately of cobbles, with some boulders and a coarse sand matrix. One landowner has constructed some wooden cribs and a concrete retaining wall in an attempt to forestall the erosion of his property. This is one of the more densely developed areas on the western side of the Bayfield Peninsula 252 SEC 25/24 T51 N R7W V W SAFETY FACTOR A-less than 1.00 B-1.00 to 1,25 0 C-greater than 1.25 )EINCE LFVErI CONFIF (high confiderice) i3-near bareholes strati.-raphy visible C-no stratigraphy visible (low confidence) 253 'Sec. 24/25, T 51 N, R 7 W Bluff: a) 10-15 ft rising northeastward to 20-25 ft; shallow slides of bluff top vegetation clumps, some rilling; 30-50% vegetation, clumps of birch, alder and fir, or horsetails; clay with sand over laminated clay over clayey stony sand and occasionally over loamy stony sand b) 20-25 ft; blockfall, some shallow sliding off crest; 0% vegetation; mostly bedrock; 2-4 ft. of clayey stony sand on top. c) 15-20 ft; shallow sliding off bluff top, rilling;,20-30% cl.umps of slumped birch, poplar; clay with sand over laminated clay over clayey stony sand over bedrock toe d) 20 ft rising to 30 southward; shallowing sliding, rilling in clay; bedrock rises and consistuted up to 1/2 of bluff and upper clay units may be absent e) 30 ft falling to 15 ft southward; shallow slides off bluff top, some rilling; 30-50% vegetation, birch, alder, and fir, or horsetails; clay with sand over laminated clay over clayey stony sand f) 10-15 ft; shallow sliding off crest; vegetation variable, mostly 10-20% slumped clumps, birch and poplar, occasional 100% meadow grasses and vines; clay units over layey stony sand g) 3-5 ft. little failure noted; 80-100% birch, poplar, fir, cedar Toe: a) mostly protected, slumped.clayey sand b) bedrock C) protected by rip-rap over clayey sand d) bedrock e) mostly protected, slumped clayey sand Beach: a.)5-15 ft cobbles with boulders; often interrupted by slide blocks b) 10-20 ft coarse sand with cobbles C) 5-15 ft cobbles with boulders; often interrupted by slide blocks d) bedrock - no beach e) 5-15 ft cobbles with boulders; often interupted by slide blocks 254 Con Vd. f) bedrock- no beach g) 5-15 ft cobbles with boulders; not as interupted by slide blocks h) 10-20 ft coarse sand with cobbles and two conc reate and wood piers i) 5-15 ft cobbles with boulders; less interupted by slide blocks j) 10-20 ft coarse sand with cobbles and one pier at south end k) 5-15 ft cobbles with a short portion cribbed with wood and less . interupted by slide blocks 1) 10-20 ft coarse sand with two piers, a retaining wall between and a wood crib at south end M) 5-15 ft cobbles with boulders; less interrupted by slide blocks 255 120- Profile 24/25-1 100- ft.to5ft.depth so- LLJ LLJ 60- LL 40- SF*=o.p9 A-B 4(XI,'. vegetation 20- A c cs 20 40 60 80 100 120 140 160 180 200 22 0 240 260 280 120- Prof He 24/2 5-2 100- ft. to5ft.deptii so- F- LU 60- Lij sr=0.91P LL A-B 00c' vegetation 40- FFmO.P78 c 20--- cs cibr 20 40 60 86 100 120 140 160 180 200 220 240 260 280 120- Profile24/25-3 100- ft.to 5 ft.depth so- F- LLJ Uj 60- U- 40- C'F*=0.6p 20- A-R 100%, vegetation C C @%-r 26 46 o!@ io 160 T 120 140 11@0 11@0 2@O 2@O 240 2@O 2@O FEET F E E T aL.N cr- 14 Lj 416 LA I J) 9sz F E E T w C> C3 C> Cor- 0 rr, Ln rn 41 m .CN. tj LSZ 258 Section 26, T51N RN (Southeast facing) The section is located:at the base of Bark Point. There is bluff present throughout, rising from less than 5 ft. at the northern end of the section to 30-40 ft. at the southern end. Most of the section has a 10-15 ft. bluff with a poorly vegetated, nearly vertical face. The bluff is composed of clay overlying clay-sand overlying sand and gravel, @nd fails.by shallow sliding or rill-wash. Most of the beach is 10-15 ft. wideand composed of boulders and cobbles with a corase sand ma trix. At the southern end of the section it narrousto a maximum of 5 ft. and is occasionally interupted by slide debris. 259 SEC 26 T51 N R7 W Frn' M CTOR A-less than 1.00 B-1-00 to 1.25 C-greater than 1.25 CONTIDENCE LEVEL A-boreho"e 0 (high confidence) B-near boreholes stratigraphy visible C-no stratigraphy Visible (low confidence) 04 260 Section 26/23, T 51 N, R 7 W southeast-facing shoreline Bluff: a) < 5 ft; mostly well-graded and vegetated (100%) with poplar and birch and cedar; clayey sand b) 10-15 ft rising to 25-30 ft southwest-ward; clay over clayey sand; shallow sliding and rilling; 0-10% large trees fallen over c) 30-40 ft; clay over sand over.clayey sand: occasional shallow slides associated with seeps; vegetated mostly 100% birch, cedar, poplar, fir: 0% on failures Toe: a) protected clayey sand b) slum ped clayey sand or sand Beach: d) 10-15 ft;,cobbles with boulder and occasional coarse sand matrix b) 0-5 ft; cobbles; interrupted by blocks from failures 261 120- Profile 26-4 100- ft.to5ft.depth so- LLJ W 60- LL 40- Sc=0.972 A-P 100 r vegetation 20- cs s 20 40 66 s6 too 12'0 140 160 180 200 220 240 260 280 120- Prof ile 100- ft. to5ft-clopt!, 80- w 60- LL 40- 20- 26 @6 a6 so 1100 1210 1140 160 180 200 220 240 2@O 280 120- Profile 100- ft.to 5 ft.depth so- w Uj 60- U- 40- 20- ss <-.- 20 40 60 so 100 120 140 11@0 11@0 260 220 240 2@O 280 FEET F E E T 3@ co 0 a. 0. C. 0 0 C. 0 0 C> a a C@ 01 pi 0 LA -4 CD, CD z9z 263 Section 35/36, T51N, R7W The section is located at the eastern side of the base of Bark Point and the southern end of Bark Bay. There is a 30-40 ft. bluff, composed of clay overlying clayey sand, present for a short distance from the northern end of the section. The bluff is well-vegetated with birch, poplar and cedar, but some shallow-slide failures do occur. The bluff height drops rather rapidly to nothing and is replaced by a beach ridge (backed by a lagoon and marsh) that comprises 80% of the section shoreline. Where the bluff is present there is a 5-10 ft. wide cobble beach. Elsewhere the beach is 20-30 ft. wide and is composed of medium sand. There are a number of small, summer cottages along the beach ridge but there is no access to this area by road. 264 SEC 35/36 T. 51.N R7W SAFETY FACTOR A-less than 1.00 B-i.oo to 1.25 C-greater than 1.25 CONFIDE\TC,'F LEVEL A-boreholes (high confidence) B-near boreholes stratigraphy visible C-no straticrraphy visible (low confidence) 0 cc C, 0 N 0 N V. M (L 265 Sec. 35/36, T 51 N, R 7 W Bluff:. a) 30-40 ft.; clay, sand, clayey sand; occasional shallow sli.ding; mostly 100% vegetated birch, poplar, cedar b) falling to 0 ft; no failures; 100% vegetated c) absent; beach ri-dge Toe: a) vegetated, b.irch, poplar, cedar b) absent; beach ridge Beach: a) 5-10 ft; cobbles wi.th sand matrix b) 20-30 ft; medium sand 266 120- Prof i le 35 --1 100- ft. to 5 ft. depth LU UJ 60- U. 40- 100'/S Vegetation 20- SF*=3.8,, 210 40 60 86 1@0 120 140 160 180 200 220 240 260 280 120- Prof ile35-2 100- ft. to 5 ft. depth 80- LU 60- LLI U- 40- 20- SP*w3.4 100% Vegetation 26 4 66 810 100 120 140 160 180 200 220 240 260 280 120- Profile35-3 100- f Uo 5 ft. depth so- LU LL 40- SP*=5.7 100% Vegetation 20- .26 @O 6@ iO 10'o 12'0 14'o 1@o 140 .20'0 220 24'0 2@0 280 FEET T. 5 1 N., R. 7 W,So c.35136 240- 220- 200- 180- rQ 160- 140 - uj LU 120 - 100 - 80 - 60 - 40- 2 3 1 20- 2 3 0 1000 2000 3000 4000 5000 C F E E T 268 Section 1, T50N, RN The section is located at the southern end of Bark.Bay. The mouth of the Bark River is at the eastern end of the section. A moderately well- vegetated beach ridge, backed by a marsh and laggon, extends throughout the section. The beach itself is.20-30 ft. wide and is composed of medium sand. There are a number of small summer cottages along the beach ridge, but there is no access by road to this area. 269 SECI T50N R7W SAFETY FACTOR A-less than 1.00 B-1-00 to 1.25 C-greater tharl 1.25 CO,NFIDFi\TCE LEVE T, A-boreholes (high confidence) B-near boreholes stratiaraphy visible C-no stratigraphy visible (low confidence) In r4 N m M Ln 270 Sec. I T 50 N, R 7 W Bluff: a) absent; beach ridge; 50-100% vegetated; maple, fir, pine, cedar, birch, poplar, shrubs and gasses-and horsetails Toe: a) absent; beach ridge Beach: a) 20-30 ft; medium sand; some horsetails on backbeach 271 120- Profile I --i 100- ft. to 5 f.t. depth so- l'- LIJ L-U 60- LL 40- 20- 017, Vegetation r 20 40 60 so 100 120 140 160 180 200 220 240 260 280 t2O- Profile 1 -2 100- ft. to5ft.depth so- w 60- Lij LL 40- 20- f-F*=4.25 0%,Veoetation @0 @O d@ 80 100 120 140 *0 180 2W 240 260 280 120- Profile 1-3 100- ft.to 5 ft.depth @J so- w LU 60- LL 40- 20- SF*al.36 0% Vegetation 20 40 60 80 100 120 140 1;0 11@0 260 22'0 24'0 2@O 280 FEET 50 N., R. 7 W,so C. I 240- 220- 200- 180 160- 140 LU LU 120 loo 80 60 - 40- 20 3 0 1000 2000 31000 4000 5000 F E E T 0 t - Ambl., - i@- @ lo 1@@ lilil @olllllllll 11111 t 4994