1
19 19 19 19 331 6 6 6 7 11 12 10 9 8 7 12 18 14 13 15 16 17 18 13 19 24 23 22 21 20 19 24 30 25 26 27 28 29 30 25 31 36 35 34 33 32 31 36 6 1 2 3 4 5 6 1 7 12 11 10 9 12 7 8 18 13 14 15 16 13 18 17 19 24 23 22 21 24 19 20 30 25 26 27 28 29 30 25 Berlin Court Grand Ditch Hepler Ditch G eorge M a r b e r g e r Ditch P i ttman Ditch Sarah Hershberger Ditch F is h e r - G o r d o n D itch B a ug o Creek W a lt e r Wisler D i t c h Middle Fork Y ellow River Middle Fo rk Yellow River M id d le F o r k Yellow R iv e r Unsicker - Craig Ditch Whishler Ditc h Unsicker - Craig Ditch Hepler Ditch mp mp Wmdp/Wd lm/Wdpr lm/Wdpr lm/Wdpr Wmdp/Wd Wmdp/Wd mp mp Wdrr Wdrr Wdrr Wdrr Wdrr Wdrd Wdrd Wdrd Wdrd Wdrd Wdrd ls lm/Wdpr ls ls ls ls Tsfc O O O O O O Wxrr Wxrr Wxrr Wdmh Wdmh Wdmh Wdmh Wdmh Wdmh Wdmh Wdmh Wdmh Wdmh Wdmh Wdmh Wdmh Wdmh mp mp mp Wdcw Wdcw Wdcw Wdcw Wdcw Wdcw Wdcw Tdp Tdp Tdp Tge Tge Tdp Tdp Tdp Tdp Tdp mp mp mp mp mp Tdp Tdp mp Wxtc Wxtc Wxtc Wsd Wgk Wgk Wdpr Wdpr Wdpr Wdpr Tdp Tdp Wdpr Wdpr Wdpr Wdpr Wdcw Wdcw Wdcw Wdpr Wdpr Wdpr Wsd Wsd Wsd Wdpr Wmdc Wmdp/Wd Wmdp/Wd Wmdp/Wd Wmdc Wdpr Wdpr Wdpr Wdpr Wdpr Wdpr Wdpr Wdcw Wdcw mp mp mp mp Tdp Tdp Tdp mp Wdce Wdce Wdce Wdce Wdce Wdce Wdce Wdce Wdce Wdce Wdce Wdce Wdce Wdce Wdpr Wdpr B RD B RD 3B RD 3B RD 3B RD 1100 W 2B RD 2B RD 2B RD DOGWOOD RD DOGWOOD RD DOGWOOD RD 3RD RD COUNTY LINE RD PLYMOUTH GOSHEN TRL CEDAR RD CEDAR RD CEDAR RD 6TH RD 6TH RD 7TH RD 7TH RD BEECH RD BEECH RD BEECH RD BEECH RD CHESTNUT ST 6B RD BIRCH RD 1ST RD 5B RD 5B RD MAIN ST MAIN ST MAIN ST MAIN ST 4C RD 5TH RD 5TH RD BEECH RD BEECH RD 4TH RD 4B RD CR 50 MAIN STREET CHEYENNE STREET MARKET STREET CR 100 CR 100 CR 1 CR 1 CR 52 CR 52 CR 3 CR 3 CR 3 CR 150 CR 50 CR 50 CR 101 W COUNTY LINE ROAD 1250 N 1100 W 1100 W 1100 W 1100 W CR 56 1100 N CR 146 1000 W 1000 W BEECH RD CR 146 CR 146 STANTON RD CR 46 CR 46 CR 46 SHIVELY RD SHIVELY RD SHIVELY RD 1350 N 1350 N 1350 N HEPTON RD CEDAR RD CEDAR RD 900 W 900 W HEPTON RD 950 W 950 W 1050 W 1050 N 1050 N 1025 W 1000 N 1200 N 1200 N 1100 N 850 W 850 W PL YM O U T H GO S H E N TRL ELKHART COUNTY KOSCIUSKO COUNTY MARSHALL COUNTY KOSCIUSKO COUNTY MARSHALL COUNTY KOSCIUSKO COUNTY ST JOSEPH COUNTY ELKHART COUNTY MARSHALL COUNTY ELKHART COUNTY ST JOSEPH COUNTY MARSHALL COUNTY Locke Nappanee A´ A T35N T34N T35N T34N R3E R4E R3E R4E R4E R5E R4E R5E 86°00'00"W 86°00'00"W 86°02'30"W 86°02'30"W 86°05'00"W 86°05'00"W 86°07'30"W 86°07'30"W 41°30'00"N 41°30'0"N 41°27'30"N 41°27'30"N 41°25'00"N 41°25'00"N 41°22'30"N 41°22'30"N Quaternary Geology of the Nappanee West 7.5-Minute Quadrangle, Indiana By Anthony H. Fleming and Marni D. Karaffa 2012 Digital cartography by Matthew R. Johnson and Laura A. Montgrain INDIANA GEOLOGICAL SURVEY John C. Steinmetz, State Geologist MISCELLANEOUS MAP 89 Basemap features from the U.S. Geological Survey (USGS) topographic quadrangle maps, scale 1:24,000 with updates from 2011 aerial photography. Marshall County road features from Indiana Department of Transportation Roads data (2005). Road features for all other counties from Indiana Department of Homeland Security Street Centerlines data (2012)(maps.indiana.edu). Hydrographic features from USGS National Hydrography Dataset High Resolution data (2008) (maps.indiana.edu) modified using 2011 aerial photography and LiDAR data. Contours and shading based on Indiana LiDAR data from 2011 compiled by M. R. Johnson. Projection: Universal Transverse Mercator (UTM), Zone 16N. Horizontal Datum: North American Datum of 1983 (NAD83). Figure 1. Simplified geologic map showing the major glacial terrains and their source lobes in and adjacent to the map area. The numbers refer to relative ages of events that produced the terrains, with 1 being the earliest. The hachured lines represent significant ice margin positions of the late Wisconsin lobes. The Elkhart River Sluiceway System, Tippecanoe River Lowland, and Bremen Lowland are polygenetic sluiceways and lake basins whose ages and origins may span most or all of the timeline. The Nappanee West 7.5-minute quadrangle is outlined in red. 0 5 N 5 Kilometers Wakarusa Upland 2b 2b. 2b. 2a. 2. 1. Middlebury Upland Foraker Upland Nappanee Ridges Bourbon Upland Plymouth Fan Bremen Lowland Mishawaka Fan Miami Hwy Ridge Leesburg Fan Tippecanoe River Lowlands Warsaw Moraines & Drainages Lake Wawasee Basin Dewart Lake Moraine New Paris Moraine Honeyville Upland Shipshewana Fan Topeka Fan Topeka Fan Cromwell Fan-moraine Sugar Hill Upland Elkhart River Sluiceway System St. Joseph River Outwash Plain Turkey Creek segment Solomon Creek segment Elkhart River segment inner ridge outer ridge Bremen Moraine Union Grove Moraine 3. 4. 4b. 4a. 5. 5a. 2d. 6. 7 8. 2c. 2d. ELKHART KOSCIUSKO MARSHALL ST. JOSEPH WHITLEY LAGRANGE NOBLE NOBLE Mo r aine Ne w b ury Miles Lake Michigan Lobe Terrains Saginaw Lobe Terrains Huron-Erie Lobe Terrains SCALE 1:24,000 CONTOUR INTERVAL 5 FEET 0 2 Miles 0 3 Kilometers 1 1 2 APPROXIMATE MEAN DECLINATION, 2012 5 ° MAGNETIC NORTH TRUE NORTH ACKNOWLEDGMENTS This map is the result of a cooperative mapping agreement between the U.S. Geological Survey and the Indiana Geological Survey. The mapping was supported with U.S. Geological Survey National Cooperative Geologic Mapping Program STATEMAP funds (cooperative agreement G11AC20237) and matching funds from the Indiana Geological Survey. COPYRIGHT 2012, THE TRUSTEES OF INDIANA UNIVERSITY, INDIANA GEOLOGICAL SURVEY, ALL RIGHTS RESERVED The information on these media is proprietary to Indiana University, Indiana Geological Survey. Any copying, adaptation, distribution, public performance, or public display of this information without the express written consent of Indiana University, Indiana Geological Survey is discouraged. This map was compiled by Indiana University, Indiana Geological Survey, using data believed to be accurate; however, a degree of error is inherent in all data. This product is distributed “AS-IS” without warranties of any kind, either expressed or implied, including but not limited to warranties of suitability to a particular purpose or use. No attempt has been made in either the design or production of these data to define the limits or jurisdiction of any federal, state, or local government. These data are intended for use only at the published scale or smaller and are for reference purposes only. They are not to be construed as a legal document or survey instrument. A detailed on-the-ground survey and historical analysis of a single site may differ from these data. LIMITATION OF WARRANTIES AND LIABILITY: Except for the expressed warranty above, the product is provided “AS IS”, without any other warranties or conditions, expressed or implied, including, but not limited to, warranties for product quality, or suitability to a particular purpose or use. The risk or liability resulting from the use of this product is assumed by the user. Indiana University, Indiana Geological Survey shares no liability with product uses indirect, incidental, special, or consequential damages whatsoever, including, but not limited to, loss of revenue or profit, lost or damaged data or other commercial or economic loss. Indiana University, Indiana Geological Survey is not responsible for claims by a third party. The maximum aggregate liability to the original purchaser shall not exceed the amount paid by you for the product. INTRODUCTION The Nappanee West quadrangle is contained within the southern part of the region formerly occupied by the core of Saginaw Lobe ice in northern Indiana. This map was made using a variety of surface observations and subsurface data. Surface observations were made using field observations, aerial photography, and LiDAR data. Several exposures are present in the map area, primarily in large highwalls of gravel pits, and the predominantly rural character of the landscape preserves numerous key morphological features in sharp detail. Subsurface data include six down-hole geophysical logs with accompanying sample sets collected during the construction of water wells and hundreds of water well records available from the Indiana online water well database (IDNR, 2012). For this map, a basin-scale sequence-based approach was used to characterize and name map units, in which the entire sedimentary sequence and its morphological elements are the basis for local map units, while the collection of sequences associated with a given ice lobe across its entire extent constitute a “megasequence”. A four-part string of characters is used to label map units based on source lobe, depositional system, surface morphology, and other features. Subsurface units in the cross section are labeled with a two- or three-part string. MAP REFERENCES Indiana Department of Natural Resources Division of Water (IDNR), 2012, Online water well record database: http://www.in.gov/dnr/water/3595.htm, Division of Water Web Site, date accessed, August 2012. OVERVIEW OF THE MAP AREA The map area is underlain by unconsolidated deposits of Pleistocene and Holocene age that range from 150 to at least 400 ft thick. The bulk of the Quaternary section is pre-Wisconsin age; late Wisconsin deposits make up the upper 30 to about 125 ft of the section. Landforms and near-surface sequences in the map area record complex interactions and onlap-underlap relations between the Saginaw, Huron-Erie, and Lake Michigan Lobes during the Woodfordian Phase of the late Wisconsin glaciation. The overall map pattern reflects the somewhat asynchronous behavior of ice margins as all three lobes competed for space in north-central Indiana. Within the map area, deposits of only the Saginaw and Huron-Erie Lobes are present at the surface, while Lake Michigan Lobe deposits occur in the subsurface. The map area is a broad, mostly contiguous, southwest-sloping upland of moderate relief, wherein predominantly clay-rich Saginaw Lobe diamictons cap a relatively thin late Wisconsin sequence that appears to be draped over a pre-Wisconsin surface. The regional southwesterly slope is punctuated by a series of low to moderate relief, mostly WNW- to ESE-trending ridges (fig. 1; Nappanee Ridges), several of which appear to mark stillstands of the Saginaw Lobe margin at various positions, while others probably represent the accentuation of uplands by negative relief of adjacent meltwater-deepened trenches. Two of the largest ridges lie at a sharply discordant angle to the regional landscape grain; however, they trend NE-SW and NNW-SSE, respectively, forming a prominent, several-mile-wide reentrant centered about the Town of Nappanee. Just west of the map area, younger Lake Michigan Lobe deposits truncate and overlie the Saginaw Lobe deposits. The Trafalgar megasequence (23,000 –15,000 radiocarbon years before present) includes both the oldest and the youngest late Wisconsin glacial sequences in the map area. The earliest Huron-Erie Lobe deposits underlie the Bourbon upland just south of the map area and extend beneath most or all of the map area in the subsurface, where they directly overlie the pre-Wisconsin surface. In the map area the Bourbon sequence is distinctly older than any Saginaw Lobe deposits where it physically underlies them. Other parts of the Trafalgar megasequence are all about the same age or distinctly younger than the Saginaw Lobe deposits. The Trafalgar diamictons (unit Td) are typically gray, carbonate-rich loams with a large amount of black shale sand derived from the Antrim Shale (Devonian) and clasts dominated by dark gray to tan Paleozoic limestone and chert from Lake Ontario, to the east of the map area. The Wakarusa megasequence (22,000–17,500 radiocarbon years before present) encompasses all of the Saginaw Lobe deposits in the map area. These deposits are at the surface over the core of the map area and over a broader area that extends northeast through much of northern Elkhart and southwestern Lagrange Counties. In the map area, Wakarusa sediments cap the surface throughout all of the Nappanee Ridges terrain. These deposits are oldest in the south, where the region truncates the Bourbon upland and become progressively younger to the northeast, where they are about the same age or slightly older than the adjacent Huron-Erie Lobe outwash fans. The Wakarusa diamictons (unit Wd) are characteristically brown clay loams with a moderate carbonate content. They are readily recognized by the large amount of Michigan Basin bedrock lithologies, notably green-gray shale and iron concretions of the Coldwater Shale (Mississipian) and light-colored quartzose sandstones of the Marshall Formation (Mississipian) from Saginaw Bay, north of the map area. Lake Michigan Lobe deposits do not crop out within the map area, though they are present at the surface over a wide area immediately to the west. In the western part of the map area, however, greenish-gray diamicton thought to be of Lake Michigan Lobe or northwestern source occurs in the subsurface in several boreholes. The diamicton overlies gray “Bourbon” diamicton of the Huron-Erie Lobe (from which it is distinguished with some difficulty) and underlies the brown, clayey Wakarusa diamicton. Constantine Mottville Adamsville Edwardsburg Middlebury Bristol Elkhart Osceola Millersburg Goshen Foraker Wakarusa Lake Wawasee Milford Nappanee East Nappanee West Map showing location of Nappanee West 7.5- minute quadrangle in relation to Elkhart County. DESCRIPTION OF SURFACE MAP UNITS 00-1072 00-1073 86-82 87-4 86-43 01-1043 Water Well Test Hole Gamma-Ray Log Late Glacial and Holocene Surficial Sediments Muck, sedge peat, sphagnum peat, and marl. Organic sediments occur in large, saturated upland depressions; low-gradient channels entrenched by meltwater and commonly hosting local drainage divides; and backswamps in abandoned channels in outwash plains. Thickness ranges widely, from less than 3 ft in backswamps in sluiceway systems to tens of feet in large, wet depressions and deeply entrenched meltwater channels. The mineral composition of the muck at any given place generally reflects the dominant textural attributes of the sediment that surrounds and underlies the deposit. Late Wisconsin Surficial Sediments (undifferentiated by lobe or sequence) Muddy deposits of interlobate glacial lakes. Silt, clay, and some fine-grained sand. Widespread in and adjacent to the Bremen Lowland (fig. 1) at elevations of 825 ft or less in the northwestern part of the map area, where one or more shallow lakes were impounded, initially against the receding Saginaw Lobe ice margin and later against the Lake Michigan Lobe to the west, and lake mud was deposited over an irregular surface on Wakarusa diamictons (Wdpr). This unit is characterized by nearly flat lake-bottom topography punctuated by small hills and ridges of clayey Wakarusa diamicton that extend up through the lake sediment. This unit also occurs in the southeastern part of the map area at an elevation of between 825 and 830 ft and is closely associated with unit ls. Thickness not well known, but is observed to be less than 10 ft in most places. Sandy deposits of interlobate glacial lakes. Fine- to medium-grained sand, with minor silt and clay. Maximum known thickness is about 10 to 12 ft. Occurs in the southern part of the map area in deeply entrenched Saginaw Lobe channels and adjacent lowlands that became impounded by Huron-Erie Lobe outwash fans, meltwater, and/or ice. Exists in a lateral facies relationship with unit lm, with much of unit ls potentially representing a distal deltaic facies of the Leesburg outwash fan (fig. 1). Occurs at elevations of 820 to 830 ft. Undifferentiated outwash. Sand and gravel, chiefly in the form of channel fills, terraces, and sheetlike bodies found in or near entrenched meltwater channels, around the margins of large kettle lakes, and as irregular upland deposits. Observed thickness typically less than 25 ft, but may appear much greater at places where surface outwash is superposed on older sand and gravel bodies. Trafalgar Megasequence (Huron-Erie Lobe): Diamicton Units Loam-textured diamicton with a thin veneer of silt or sandy loam at places. Occupies a low-lying, gently rolling plain at the toe of the Bourbon upland. The underlying diamicton occurs in uniform sections 30 to 60 ft thick, and is interpreted to be basal till. It typically overlies a sheet of sand and gravel that, in turn, lies on the pre-Wisconsin surface. Some areas are scoured or “washed” by meltwater, creating quasi-streamlined erosional channels with a thin veneer of outwash sand and gravel, organic sediment, and lake mud. Trafalgar Megasequence (Huron-Erie Lobe): Outwash Fans and Ice-Contact Stratified Drift Collapsed outwash fan composed chiefly of coarse, locally pebbly sand. The front and sides of this fan terminate abruptly and irregularly in short scarps. The surface is irregular. This unit is mapped near the toe of the Bourbon Upland in the southwestern corner of the map area. This small area is part of much larger outwash fan systems south of the map area. The fan appears to have been deposited on and against stagnant ice that subsequently melted, causing the fan to collapse. The thickness of sand underlying this collapsed surface is typically 15 to 30 ft, but can change abruptly. The outwash (20 to 30 ft thick) overlies loamy Huron-Erie Lobe diamicton (unit Td in cross section). Esker. Winding, north- to northwest-trending ridge of gravel and sand protruding through the surface of the outwash fan (unit Tsfc) in the extreme southwest corner of the map area. The irregular summit of the ridge stands between 10 and 30 ft above the fan surface. The esker extends for at least another mile south into the Bourbon quadrangle. Sparse data indicate that the gravel may be about 50 ft thick, which means the esker extends well below the surface of the surrounding outwash fan. The esker is inferred to be partly buried by, and thus older than, the fan (unit Tsfc). Wakarusa Megasequence (Saginaw Lobe): Diamicton-Based Map Units Meltwater-washed channels floored by clayey diamicton, and locally capped by small bodies of outwash, lake mud, and organic sediment. This unit occurs in the Nappanee Ridges region (fig. 1), where it forms shallow and typically narrow channels that parallel the fronts of several diamicton-cored ridges. Each ridge-channel pair probably represents a minor end moraine or other short-lived stillstand of the ice margin, with the channels originating as ice-marginal channels that were occupied briefly by meltwater. The sequence beneath the channel floors is generally similar to that elsewhere in the Nappanee ridges—a stack of diamictons with tabular bodies of granular sediment occurring at places along stratigraphic boundaries. The surface-capping Wakarusa diamicton is eroded in the channels and, thus, somewhat thinner than in adjacent uplands. Collapsed outwash fan lobes are composed chiefly of coarse, locally pebbly sand. Entrenched channels that cut through the regional diamicton sequence of the Nappanee Ridges. This unit makes up the steep walls of two prominent WNW- to ESE-trending channels that separate three parallel ridges in the region near the city of Nappanee. The depth of incision is 40 to 50 ft and locally more. As a result, the channel walls cut completely through the Wakarusa diamictons into underlying Huron-Erie Lobe till of the Bourbon sequence. Thin, greenish- gray diamicton of the Wedron Megasequence (Lake Michigan Lobe) may also be present in the walls of the far western part of the southernmost channel, in German Township (Marshall County). The channels do not appear to penetrate the pre-Wisconsin surface. Small- to medium-sized outwash terraces commonly hang on the channel walls, and a much larger set of terraces floors the western end of the southernmost channel. Elsewhere, the channel walls terminate against terraces of lacustrine sediment (lm, ls) or in thick organic deposits (mp). The channel walls are somewhat dissected and locally exhibit a collapsed appearance, indicating that they are probably veneered with debris flows. High-relief hummocky end moraines cored by thick clayey diamicton interbedded with sporadic lenses of sand and gravel. This unit makes up the Bremen Moraine (fig 1). The Bremen Moraine stands 50 to 60 ft above adjacent lowlands at its highest point. It is broad and features strong hummocky topography just outboard of its summit area, where this unit is mapped. The clayey Wakarusa diamicton that cores the moraine is 25 to 50 ft thick. This unit includes tabular to irregular bodies of gravel and sand at various horizons. A widespread sheet of sand and gravel as much as 25 ft thick persists in the subsurface just below the summit of the moraine, and appears to be a proglacial outwash apron that was overridden as the Saginaw Lobe margin advanced onto the moraine. The surface material of this unit consists chiefly of supraglacial diamicton and some lake sediment. Compact basal till appears to be more abundant at depth. Rolling plains of diamicton. Together with units Wdrd and Wdrr, this unit composes the typical landscape of the Nappanee Ridges region and accounts for a large proportion of the gently southwest-sloping upland surface. The landscape contains low, rolling hills and ablation hummocks and long, straight slopes having grades less than 5 percent. Scattered shallow depressions occur throughout but are never abundant. The sequence below this unit is typified by a very thick stack of late Wisconsin and pre-Wisconsin diamictons, capped by 20 to 30 ft of clayey Saginaw Lobe supraglacial sediment and basal till. Thin units of sand and gravel occur sporadically along stratigraphic boundaries, the two most common being at the base of the Wakarusa diamictons and along and just below the pre-Wisconsin surface. Local relief does not exceed 10 ft except for an isolated group of ridges in the center of the unit that stand 15 to 20 ft above the surrounding plain. Individual ridges are seldom more than a half-mile long, but multiple ridges are commonly aligned along vague arcuate to linear belts and may be paralleled by shallow drainages that may or may not be connected to other channels. The local relief of the ridges corresponds to a thickening of the clayey Wakarusa diamicton. Dissected, diamicton-cored ridge. This unit makes up the front of the “outer” Nappanee ridge south of the town of Nappanee, lying along the northern flank of the deeply entrenched channel that separates this ridge from the Bremen Moraine further south. It occupies the same geomorphic position as unit Wdce but is not as steep and has a better integrated and more intricate network of longer ravines, whose fingers extend well into the adjacent summit area of the ridge. The underlying geology consists of the same thick diamicton sequence found elsewhere in the Nappanee Ridges region and, like unit Wdce, the slope cuts across that sequence, bringing older units close to the surface at lower elevations. The unit has a more varied assemblage of near-surface sediments than the adjacent ridge crest, however, including a considerable number of small outwash bodies along drainages and on mid-slope terraces. The dissection of this landscape likely occurred shortly after it was deglaciated, when ice stood near the summit of the ridge and meltwater was directed downslope into the adjacent trench. Broad, low, rolling diamicton-cored ridges. In some places, the relief of the ridges corresponds to a thickening of the Wakarusa diamicton that cores them, but in others the ridges appear to be situated over highs on the pre-Wisconsin surface, which is seldom more than 50 ft below the surface in this region and locally within 30 ft. Some, and perhaps all, of these ridges originated as minor end moraines. Small patches and sheetlike bodies of sand and gravel occur in and adjacent to south-trending high-level drainages leading into unit Wdrd. Wakarusa Megasequence (Saginaw Lobe): Outwash Fans, Deltas, Ice-Contact Stratified Drift, and Related Meltwater-Deposited Units Broad, undulating ridge composed of sand and some silt. This NE- to SW-trending ridge is about a mile wide and several miles long. It is composed almost entirely of silty sand and fine- to medium-grained sand up to 60 to 70 ft thick. Some pebbly sand is reported in well records in the highest parts of the ridge. The ridge stands 10 to 25 ft above the terrain to the east, but as much as 50 to 60 ft above the low-lying lake plain to the west. The ridge is closely associated with units Wmdc and Wmdp and constitutes the head of a fan-delta system marking the active western margin of the Saginaw Lobe as it stood along the edge of a proglacial lake in the Bremen Lowland (fig. 1). A much smaller, somewhat lobate body of sand, interpreted to be a small delta, in the southern part of the quadrangle is also assigned to this unit. Collapsed, hummocky upland with a planar summit, underlain by lacustrine mud and fine-grained sand. The unit lies immediately outside of unit Wsd; the upland surfaces of the two are contiguous, defining a smooth, gently WNW-sloping delta topset. Unit Wmdc was deposited over one or more blocks of stagnant ice; it occupies a reentrant in the Bremen Lowland, bounded on the north by a rolling diamicton-cored upland and on the east by the sandy ridge of unit Wsd. Small, uncollapsed areas within the unit define a near perfectly smooth top surface that dips gently and regularly west-northwest at about 15 ft per mile. The lake sediment that makes up the unit appears to be as much as 25 to 30 ft thick and somewhat sandier at the eastern end, becoming progressively thinner and more muddy lakeward. Clayey diamicton of the Saginaw Lobe underlies the lake sediment and may be intercalated with it in strongly collapsed areas. The gradational southern and western boundaries of the unit blend into the more distal parts of the delta and undifferentiated lacustrine sediments of the Bremen Lowland, respectively (units Wmdp/Wd and lm/Wdpr). Low-relief lake plain underlain by lacustrine mud and deltaic outwash deposited over a rolling diamicton surface. This unit is characterized by nearly flat lake- bottom topography punctuated by small hills and ridges of clayey Wakarusa diamicton that extend upward through the lake sediment. Local relief is rarely more than 5 to 10 ft. The surface of this landscape slopes very gently westward at about 5 to 7 ft per mile and thus appears to be a more distal continuation of the westward-sloping delta surface associated with units Wsd and Wmdc. The lake mud appears to be less than 10 ft thick, being thickest in the broad flats and diminishing to nothing adjacent to diamicton hills. Clayey Wakarusa diamicton (some of which is probably waterlain) forms the immediate substrate and caps a thick stack of older diamictons that includes much pre-Wisconsin sediment. This landscape is similar to and transitional with that of the adjacent lacustrine unit lm/Wdpr. The chief distinction is the lower elevation of the latter, which continued to collect meltwater and sediment from the Lake Michigan Lobe well after the Saginaw Lobe withdrew from the basin. Conical hill composed chiefly of gravel. Gravel thicknesses greater than 130 ft were observed in some wells high on the hill. Thick diamicton is commonly reported in wells lower on the flanks, and basal till of the Huron-Erie Lobe (presumably the Bourbon sequence) is exposed at the base of the deformed gravel at an elevation of about 875 ft. Beds of coarse gravel exposed in a large gravel pit on the west side of the hill dip away from the summit at angles as great as 40 degrees, indicating deposition against walls of ice. The feature is a classic moulin kame. Features indicate that the kame is situated on a buried topographic high on older units. Several much smaller kames, less than 40 ft tall, occur near the crest of the Bremen Moraine in the southern part of the Nappanee Ridges region. Low, rolling to hummocky ridge composed of sand, Wakarusa diamicton, and some lacustrine mud. Local relief is 25 to 30 ft thick. This east- to west-trending feature lies between the rim of a deep channel (Wdce) to the south, a prominent ridge of sand to the northeast (Wsd), and a shallow drainage along the fringe of the Bremen Lowland/lake plain to the north (fig. 1). Its morphology and position relative to surrounding features suggest that it was deposited in or on stagnant ice and could be an extension of the delta system mapped to its north and east (units Wsd, Wmdc, and Wmdp). Narrow, deep (10 to 20 ft) tunnel valley with strongly collapsed and chaotic topography. The tunnel valley cuts completely through the host Wakarusa sediments into older sequences below. The composition of the walls and floor is varied and unpredictable. The walls consist of a chaotic jumble of collapsed diamicton with numerous patches and terraces of sand and gravel. The floor of some segments appear to be cut into older diamictons having a veneer of sand and gravel, while other segments are underlain by deep, narrow bodies of gravel, but much of the floor detail is obscured beneath bodies of organic sediment and irregular masses of collapsed wall sediment. Latest direction of meltwater flow. Relic drainageway across uplands. Approximate contact. Diamicton hummock protruding through lake basin. Wgk Wxrr Wxtc Wmdp/ Wd Wdmh Wdpr Wdrd Wdrr Wsd Wmdc Wdce Wdcw Tge Tsfc O Tdp mp lm/ Wdpr ls CORRELATION OF MAP UNITS surface and cross section Trafalgar Megasequence (Huron-Erie Lobe) Jessup Formation Banner Formation (West Lebanon Member) Wakarusa Megasequence (Saginaw Lobe) Wedron Megasequence (Lake Michigan Lobe) TIME DIVISION QUATERNARY Holocene late Wisconsin pre-Illinoian Illinoian Sangamon lake sediment/erosion lake sediment/erosion organic beds weathering weathering weathering weathering Wmdc Wxrr Wgk Wsd Wdmp/ Wd Wdce Wdcw Wxtc Wdmh mp Wdpr Wdrd Wdrr ls O lm pW1 pW2 pW3 pW4 pWu Tdp Tsfc Tge Ws/Wg Ts/Tg Ts/Tg 7153 79012 86-82 (1 mile NW) 87-1 79416 389632 355570 237301 390644 319204 2848868 79411 280164 79449 390642 79414 79369 390641 366144 79384 78494 78499 395592 307692 342425 77159 332429 304595 283392 348767 332556 326165 317476 398560 251234 274647 00-1073 47392 vertical exaggeration: 25x Inter- and Intra-sequence boundaries known approximate queried (interpreted) Intra-sequences lithofacies boundary top of pW1 - West Lebanon Member boundary between pre-Wisconsin sequences pre-Wisconsin surface 366144 water well location and Id 87-1 IGS gamma-log location Undifferentiated sand sand and gravel organics Ws Wg Wd Wakarusa diamicton gravel sand sand/gravel pre-Wisconsin diamicton pW# Lake Michigan Lobe diamicton Ts Ts Tg Td Trafalgar diamicton gravel sand Wsg mp s sg Subsurface Units Walter Wisler Ditch Fisher Gordon Ditch Berlin Court Ditch Armey Ditch Dausman Ditch Tg Ws O Ts Ts Ts Ts Ts Ts Ts Ts Ts Ts Ts Ts Ts Ts Ts Tg Td Td Td Wd Td Wd Td Wd Wd Wsg Bedrock (Ellsworth Shale - Late Devonian) West Lebanon Member Banner Formation Wedron Fm L. Michigan Lobe mp mp mp mp Wg Tg pW4 pW4 pW4 pW1 pW2 pW3 pW4 pW1? pW2 pW2 pW3 pW2 pW3 Ws older pre-Wisconsin undivided older pre-Wisconsin undivided bend in section bend in section bend in section sg sg s sg sg sg sg sg sg sg sg sg sg sg sg sg sg sg s sg sg s NE SW A´ A 660 620 860 820 780 740 700 620 660 820 780 740 700 INDIANA Map of Indiana showing location of Nappanee West 7.5-minute quadrangle. Map showing the Nappanee West 7.5-minute quadrangle and the distribution of data points in the map area.
