Bedrock topography of the Middle Illinois River Valley : Bureau, Marshall, Peoria, Putnam, and Woodford counties, Illinois

              2
°APPROXIMATE MEANDECLINATION, 2009MAGNETIC NORTHTRUE NORTH
QUADRANGLES
1 Princeton South
2 DePue
3 Spring Valley
4 Putnam
5 Florid
6 McNabb
7 Lacon
8 Henry
9 Varna
10 Rome
11 Chillicothe
12 Washburn
1
23465789101112
Geology based on field work by E. Donald McKay III, Richard C. Berg, C. Pius Weibel, and Andrew J. Stumpf, 2001–2007.
Digital cartography by Jennifer E. Carrell and Jane E.J. Domier, Illinois State Geological Survey.
The Illinois State Geological Survey and the University of Illinois make no guarantee, expressed or implied, regarding the correctness of the interpretations presented in this document and accept no liability for the consequences of decisions made by others on the basis of the information presented here. The geologic interpretations are based on data that may vary with respect to accuracy of geographic location, the type and quantity of data available at each location, and the scientific and technical qualifications of the data sources. Maps in this document are not meant to be enlarged.
1
7 KILOMETERS0124356SCALE 1:62,50015 MILES10234
Base map compiled by Illinois State Geological Survey
from digital and paper data provided by the United States
Geological Survey.
North American Datum of 1983 (NAD 83)
Projection: Transverse Mercator
Recommended citation:
Berg, R.C., C.P. Weibel, A.J. Stumpf, and E.D. McKay III, 2009, Bedrock Topography of the Middle Illinois River Valley, Bureau, Marshall, Peoria, Putnam, and Woodford Counties, Illinois: Illinois State Geological Survey, Illinois Map 15, 1:62,500.
R
OAD CLASSIFICATIONInterstate RouteU.S. RouteState Route
Institute of Natural Resource Sustainability
William W. Shilts, Executive Director
ILLINOIS STATE GEOLOGICAL SURVEY
E. Donald McKay III, Interim Director
Illinois Map 15
2009
For more information contact:
Institute of Natural Resource Sustainability
Illinois State Geological Survey
615 East Peabody Drive
Champaign, Illinois 61820-6964
(217) 244-2414
http://www.isgs.illinois.edu
© 2009 University of Illinois Board of Trustees. All rights reserved.
For permission information, contact the Illinois State Geological Survey.
BEDROCK TOPOGRAPHY OF THE MIDDLE ILLINOIS RIVER VALLEY
Bureau, Marshall, Peoria, Putnam, and Woodford Counties, Illinois
Richard C. Berg, C. Pius Weibel, Andrew J. Stumpf, and E. Donald McKay III
2009
R
OMEMARKVARNALACONHENRYPUTNAMTOLUCAMCNABBDE PUEWASHBURNMAGNOLIAHOPEWELLHENNEPINTISKILWASTANDARDCEDARPOINTSPARLANDGRANVILLECHILLICOTHESPRING VALLEYPERUBUREAUJUNCTION4326147532518557263567545458641771831693163612256621582315888797948671628994222985972547133445973488549489983862526849736511846887178939535163417273322655149263569527139131311130301911311111111718111111111118111120192911112032321132913172415143112303012102017181617143117241816193631162620351321232336202222181432303430282129292421231910321217181918143435139351933243216231530332735351231332023132512141335253610123636193422241019173316361724173326231529241335252820281315202524171628314142114262428351222262028363631223025223127427341718232717163530122421252221191815213315122335321520333526172727292910102429118271628343618212232343320212330313433363132361522342533342023202834352010262436132531263510141529141232331912323635181429322331527311910142322142216221823271732161729183435252621222835192132261314261529262928203327243135163236293433291730262127301020332262334102031162522322527363220172113252029283619272032153614121024343215272528262535343234321336101832341717333423162127302833116302017192032292517291929121813251915303031163131243018193119313182634301019304193151631201636332710211512322622283521292715103182162633413281535262115222810510232435323102124286622332333283233216321114T 31 NT 12 NT 12 NT 30 NT 11 NT 10 NT 29 NT 16 NT 15 NT 33 NT 13 NT 14 NT 32 NR 10 ER 9 ER 3 WR 9 ER 8 ER 9 ER 8 ER 2 WR 11 ER 1 WR 2 WR 1 WR 1 ER 1 WR 1 E2929292626267161801801818181711789898989892926261717629MARSHALL COMARSHALL COMARSHALL COWOODFORD COPEORIA COPUTNAM COPUTNAM COPUTNAM COBUREAU COLASALLE COILLINOISRIVERGooseLakeMeadowBabbSloughDouglasLakeLakeWrightmanLakeGooseLakeGOOSELAKESENACHWINELAKEILLINOISILLINOISRIVERRIVERSndySandyDryCedar JuddAllforks Henry CreekStrawnSpring Negro Deer CreekHallockCreekCreekCreekCreekCreekCreekCreekCreekCreekCreekCreekCreekCreekBrownsPigeonCrowShawClear SnagLittleRichlandCoonBig Bureau CreekThenius CreekGimlet CreekCreekGilfillanSenachwine Run SandyCreekCreekCreekCreekCreekOld Channel Big Bureau CreekSenachwine CreekCrow CreekLittle Senachwine CreekCreek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igure 2"k"e"k"k"e"e"e"e"kS"e"k"e"e"e"k"e"k"k"e"e"e"e"e"e"e"k"e"e"e"e"e"e"e"e"e"e"e"e"k"k"e"e"e"k"k"e"k"k"k"kS"kS"e"k"e"k"k"e"e"e"e"k"e"e"e"k"k"e"k"k"k"k"kS"kS"k"e"kG"e"k"k"k"e"k"k"k"k"k"k$0"k"e"e"k"k"k"e"k$0$0$0"k"k$0"k$0"k$0"k$0"e"e"k$0"k"k"e"k"e"k"k"k"e$0"k$0$0"k$0$0"k"e"k"e"k"e"k"k"k"e"k"k"k"k"k"k"k"k"k$0$0"k"k$0$0"k"e"k$0"e"k"k"e"e"k"k"k"e"e"k"k"kS"k"e"k"k"k"kS"e"k"kS"k"kS$0"kS""kS"k"k"e"e"k$0$0"k"e$0"e"e"e$0"e"k"e$0"k"e"k"k"k"e"k"k"e"k"e"k"e"k"e"e"e"e"e"e"e"e"e"e"e"e"e"k"k"k"e"k"k"k"k"k"k"e"e"k$0"e"k"e"e"k"e"e"k"e"k$0"k$0"e$0"e"k"k"k"k"k"e"e"k$0"e$0"e"k"e"k"k"e"k"e"e"e"e"k"k"k"k"k"e"k"k"k"k"e"k"k"k"k"k"k"k"e"k"e"k"e"e"k"k"k"k"e"e"e"k$0"k"e"k"k"e"k"k"k"k"e"e"e"e"k"e"k"k"k"k"k"e"k"k"e"k"e"k"k"e"k"e"e"k"e"k"e"e"e"e"k"k"e"k"e"e"k"e"k"k"k"k"e"e"k"e"e"k"e"e"e"k"e"e"e"k"k"k"k"k"k"e"k"k"e"e"k"e"e"k"k"e"e"e"k"kS"k"kS"e"kS"k"k"k"k"e"e"e"e"e"e"k"e"e"e"k"k"e"e"k"e"k"e"k"k"k"e"k"k"e"e"e"e"e"e"k"k"e"k"k"k"e"k"k"k"e"e"k"k"e"k"k"k"e"e"k"k"k"k"e"e"k"k"k"k"e"e"e"e"e"k"k"k"e"e"e"e"e"e"k"e"k"k"e"k"e"k"k"e"e"k"e"e"k"e"k"k"e"e"e"e"k"k"k"e"e"k"e"e"e"k"k"k"k"e"k"k"k"k"e"k"k"k"k"k"k"k"k"k"e"k"e"k"k"k"k"k"k"e"k"k"k"k"e"e"k"k"k"k"k"e"k"k"e"k"k"e"k"k"k"k"k"k"e"e"k"k"e"e"e"e"e"k"k"k"k"k"e"k"k"e"e"k"e"k"k"k"k"k"k"k"k"k"k"k"k"k"k"e"k"k"k"k"k"k"k"k"k"kG"k"k"k"k"k$0$0$0"kS"k"k"k"kS"kS"k"kS"kG"k"k"k"k"k"k"kS"kS"e"e"k"k"k"e"kkkkkkke<649<598<453<480<414<400<376<402<405<401<400<416465<397395<450584<602399466<440460611403580<421478570<470625<574600<476<425<421576<410484569589551460<615442402450426415424442561367414<410445<450<463554494<430389389500383437<394<428<387<426<445<431386582<451<359399422380576376530<376490555<493547386<450546574389562368<432<365583409401491<504391563587415591522<447572<399377351341357567351445581475563<463404414489584<392335493385374<485<468<557450<495<507454427459<412<380<535<528523389<421409410<380<436<484442<418<416490509<411494<398391562<504348<477<363<587<377<406<498390568586<420<449<553<371<435399597369399559<692<550410514597410406403<419<418563586401<587571406<500<539580569574395<428384<423394597<439<426<460569<431485500<417<424446430<562<586<504<415<412<393393389<383382434574378<480631<568600<417<430547595<551<445<439362<505<436<500<445<422<550377382352534398404<377389384405412<396<405<435<403376623<397<415605<417<404405405<392405408396593589411<400<390<397401<446<472<542385<556<464389<410<400387380397404<441382<415<550410<424380380<520<540<570<502412<434499<402<600400<412592508<431496<560400317<396422406404566396<452<447556<423<500<429<407402409404499<405392395<465404520421<394<397<535406405406645469<530<421458<433352<432581584403406408404410631<390389440385386<432452607558591548<419<412<422<408402<418395623<432485<400482<421560401<436<436475489601470420<433485<423510630527375<434<442<388643<407<429395<411<446472446<617<436380388382424639455615<576439443454421<370<614<600<600406625<578402, 409490478386444471<397417<437604469422488<432<360<432496439484<413<398480562<400493581<400487481595459422559570412<441469<440431396417390<420482<396367579<450478558586463570565381582<405580579<415<411560462554475554474515474540591500551502<367495503400<403<424385500487446<380440455465527<395<380<391443<440<547<408<439423422<437409<604388<454423421<398<387<600405397<398<425<538<602<588<574<558<417<560<412<403<389585<410<600<427<422<403<412<392383376<369395<423<379<421612<428372<593<429<430<350373397<453626394427486<415<427<435<414658412445414473583563455518526446572605582421607611445505545432557482393406408440513550594569575552562438403555549442464461343964075664724216145694704765575934245925314434213984134404085853935604175815905725724245914294626024394456054335555295616066004152339451754555957738545848855161455148846852743846555954548243861945244048644244438859059752649058753145158144458257157142057618550541393452460TICONA BEDROCK VALLEYData TypeBedrock outcropOutcrop in field notes (ISGS archives)Stratigraphic test boring (ISGS)Water-well boringEngineering boringCoal boringOther boringLabels indicate samples (S) or geophysical log (g). Boring labels indicate bedrock elevation in feet above mean sea level. Less than symbol (<) indicates boring did not reach bedrock. Bedrock elevation is lower than the value given. Dot indicates boring is to bedrock.Geophysical profile transectNote: Well and boring records are on file at the ISGS Geological Records Unit and are available from the ISGS Web site. "e"e"e"e"k<406$T$TSGeBedrock Elevation(feet above mean sea level) 680660640 620600580560540520 500 480460440420 400 380360340320300
Introduction
This bedrock topography map reveals geomorphic features created by the ancient Mississippi River, the ancient Illinois River, the modern Illinois River, and numerous glacial advances and retreats. In the map area, the bedrock surface is buried beneath as much as 330 feet of glacial and post-glacial sediments. The overall relief (i.e., hills and valleys) of the bedrock surface affects the types of bedrock at its surface. This relationship is important for depicting the depth to bedrock for drilling operations and for predicting the distribution of shallow, economically significant rock resources. Most important, mapping of the bedrock topography delineates buried bedrock val­leys, which often contain sand and gravel deposits that are aquifers.
At the northern edge of the map is an east-west–trending deep channel (<360 feet in elevation), which is the downstream end of the Upper Illinois Bedrock Valley. The modern Illinois River flows within this channel. Entering this reach is the down­stream portion of the Ticona Bedrock Valley (Willman 1940). West of this juncture is the “Big Bend” (near Hennepin), where the axis of the Illinois River valley changes to a southerly orientation. The Big Bend is the point at which the relatively narrow Upper Illinois Bedrock Valley widens to the 10- to 15-mile-wide Middle Illinois Bedrock Valley (MIV). It is also from this point that the MIV bifurcates into two newly recognized valley-bottom channels (herein called the MIV East and MIV West Channels) that extend south for more than 20 miles in the central portion of the map. The two channels are separated by a low-lying rise that is elevated 20 to 40 feet, and near the Marshall-Putnam County boundary, they are connected by a smaller, shal­low, northwest-southeast channel. About 5 miles south of the Big Bend, the Princeton Bedrock Valley, part of the ancient Mississippi River, joins the MIV from the north­west. In the southern portion of the map, the two channels merge to form a single channel about 4 miles north of the junction (near Chillicothe) of the tributary Wyo­ming Bedrock Valley and the MIV. Beyond the southern map boundary, the MIV extends to the Peoria-Pekin area where it merges with the Danvers, Mackinaw, and Mahomet Bedrock Valleys (Herzog et al. 1994).
In general, the west wall of the MIV is steeper than the east wall, primarily because much of the modern western wall, particularly the middle portion, is a local high on the bedrock surface where numerous bedrock exposures occur up to 600 feet in elevation along the wall and along tributary valleys. The bedrock landform that is the western upland is relatively flat but slopes both northward and southward into the Princeton and Wyoming Bedrock Valleys. The east valley wall, which is known only from drill-hole data, is characterized by low erosional terraces. Several shallow, east-west valleys are incised into the eastern bedrock uplands.
This map covers nine 1:24,000-scale 7.5-minute quadrangles—Putnam, Florid, McNabb, Lacon, Henry, Varna, Rome, Chillicothe, and Washburn—and the southern half of three quadrangles—Princeton South, DePue, and Spring Valley. It revises smaller-scale statewide bedrock topography maps produced by Horberg (1950, 1957) and Herzog et al. (1994). This present, more detailed map was an outgrowth of map­ping for a proposed Illinois Department of Transportation highway improvement proj­ect along Illinois Route 29 on the west side of the Illinois River north of Chillicothe (Berg et al. 2002, 2003).
Methodology
Except for exposed bedrock along the western wall of the MIV, the bedrock through­out most of the study area is buried by glacial and post-glacial sediments. The bed­rock elevation contours for the Princeton Bedrock Valley and for data-sparse areas along the western portion of the map were based on those of Herzog et al. (1994). For the remaining larger portion of the map, the elevation of the bedrock surface was de­termined by evaluating logs of borings and seismic profiles. A total of 1,124 elevation points were used from logs of water wells, engineering borings, and coal test borings. All data points are shown on the main map except for the Rome Quadrangle (fig. 1). The logs were supplemented with data from 21 Illinois State Geological Survey exploratory test borings and numerous field-described outcrops. These data are on file in the ISGS Geological Records Unit. Locations of borings were verified by matching property owners’ names and addresses on drillers’ logs to (1) county plat books show­ing land ownership, (2) observable houses on aerial photographs, or (3) name and address citations in phone books or by site visits. Locations were then plotted by hand and/or digitally on 1:24,000-scale topographic maps. A total of 483 boreholes reached the bedrock surface. Bottom elevations of many other borings ending in deposits above bedrock were used to “force down” bedrock surface contours, complementing nearby definitive elevation measurements.
In the northeastern portion of the map (see boxed area on map and Figure 2), seismic reflection profiles made along 5.15 miles of roads were used to redefine the geometry of the Ticona Bedrock Valley where it enters the Upper Illinois Bedrock Valley (Mur­phy 2005). Logs of nearby water wells were used as a basis for estimating seismic velocities of glacial-fluvial deposits, which allowed conversion of seismic travel times to estimated bedrock surface elevations. Ninety-six virtual boreholes, spaced about 300 feet apart, were developed; each provided a depth to bedrock that was inferred from the regional bedrock morphology and used to constrain the computer program that generated the map.
Along the 10-mile extent of the western bluff of the Illinois River Valley and in tribu­tary valleys where bedrock is exposed, a digital elevation model (DEM) of the ground surface was used to partially define the elevation of the modeled bedrock surface. The DEM was complemented by field examination of numerous bedrock outcrops in the area. Elsewhere, the digital bedrock surface was created with the Topo to Raster tool in the Spatial Analyst extension of ArcGIS version 9.2 with a grid size of 30 m. In portions of the valley where data were too sparse for computer contouring to replicate channels, the valley bottom was interpreted by modeling the thickness of the sand and gravel unit (Henry Formation) overlying bedrock and then using the elevation of the bottom of that unit to define the bedrock valley shape.
Observations
The following observations of the bedrock topography of the MIV reflect the complex drainage history of the ancient Mississippi and modern Illinois Rivers, including ero­sion and sedimentation events, channel formation and widening, and the final diver­sion of the ancient Mississippi River to its present channel.
• The MIV has pre-glacial origins (Herzog et al. 1994) and was a drainageway for pre-Illinois episode meltwater. Throughout the Pleistocene and up to the time of its diversion, the ancient Mississippi River drained much of the midcontinent of North America through the present-day Illinois River valley to the Gulf of Mexico.
• New regional geologic mapping has provided sufficient new field observations and new data that better characterize erosion and deposition associated with glaciers repeatedly crossing the valley. The ancient Mississippi River had reoccu­pied the valley upon glacial retreat several times during the last several hundred thousand years until being blocked by a glacier that diverted it to its present Mis­sissippi River course 20,780 ± 140 radiocarbon years before present (14C yr BP) (McKay et al. 2008). Prior to 20,780 14C yr BP, the Princeton Bedrock Valley and the MIV constituted the ancient Mississippi River valley. This bedrock topogra­phy map reflects that complex history.
• Recent stratigraphic studies, including extensive field sampling and test drill­ing, reveal that the most extensive, oldest, and thickest deposits occur below land surface on uplands east of the Illinois River and west of the eastern bedrock valley wall (McKay and Berg 2008). The oldest OSL (optically stimulated lumi­nescence) dates (185,000 to 190,000 years ago) in the region were obtained from early Illinois Episode fluvial quartz sand between elevations of 320 and 325 feet and below Illinois and Wisconsin Episode diamictons (NE¼ SE¼ NW¼, Sec. 4, T30N, R1W, Marshall Co.) within the thalweg of the MIV East Channel. The bedrock topography map also shows that the MIV East Channel overdeepened on the outside of two prominent meander bends. Stratigraphic data indicate that the MIV East Channel is the oldest part of the bedrock surface in this reach of the ancient Mississippi River. Other parts of the bedrock surface appear to have been eroded more recently, explaining why deposits older than the Illinois Episode have not been found (McKay et al. 2008).
• The Illinois, Sangamon, and Wisconsin Episode deposits indicate that the gla­ciers advanced and retreated across the valley several times, allowing the river to repeatedly occupy the valley after each retreat. Undulations of the bedrock valley floor, the width (up to 15 miles) of the bedrock valley, and its burial beneath the adjacent uplands reflect the complexity of erosion and sedimentation associated with these events. In general, this recent mapping infers that the ancient Missis­sippi River has gradually widened its valley, mainly by eroding its western bluff since the early part of the Illinois Episode. The swale between the bifurcating channels may have been functional during the Illinois Episode when meltwaters flowed down the Ancient Mississippi River Valley.
• Glacial and fluvial erosion along the western valley wall and into the tributar­ies has been ongoing at least since the early Illinois Episode. Illinois Episode diamictons and sand and gravel have infilled the bedrock valley beneath Rattle­snake Hollow (S½ Sec. 27, T12N, R9E, Marshall Co.) and are overlain by the Sangamon Geosol and Wisconsin Episode glacial and fluvial deposits.
• A prominent valley more than five miles long, just west of the Ticona Bedrock Valley, presumably could have carried overflow from the Ticona directly into the MIV during the Illiniois Episode.
• The MIV West Channel is occupied by deposits that probably post-date the last diversion, and the present Illinois River flows roughly above the MIV West chan­nel.
Acknowledgments
The authors thank the Illinois Department of Transportation for providing the funds to begin mapping of the Middle Illinois Valley for transportation planning. They also thank landowners who allowed the ISGS access to their property for drilling and field work, and local water well contractors and county highway departments who provided new logs of water wells and engineering borings. Finally, the authors thank Mike Smith (University of Kingston, United Kingdom) and Andrew Phillips (ISGS) for their thoughtful reviews and comments, Jennifer Carrell (ISGS) for digital cartog­raphy, and Jane Domier (ISGS) for overall cartographic review.
References
Berg, R.C., E.D. McKay III, D.A. Keefer, and R.A. Bauer, 2003, Geologic mapping for highways in Illinois: Providing information for transportation planning and construction: Geological Society of America Annual Meeting, Abstracts with Programs, v. 35, p. A–65.
Berg, R.C., E.D. McKay III, D.A. Keefer, R.A. Bauer, P.D. Johnstone, B.J. Stiff, A. Pugin, C.P. Weibel, A.J. Stumpf, T.H. Larson, W.-J. Su, and G.T. Homrighouse, 2002, Three-dimensional geologic mapping for transportation planning in cen­tral-northern Illinois: Data selection, map construction, and model development, in L.H. Thorleifson and R.C. Berg, conveners, Three-dimensional Geologic Map­ping for Groundwater Applications, Workshop Extended Abstracts: Geological Survey of Canada, Open File 1449, p. 13−17.
Herzog, B., B.J. Stiff, C.A Chenoweth, K.L. Warner, J.B. Sieverling, and C. Avery, 1994, Buried bedrock surface of Illinois: Illinois State Geological Survey, Map 5, 1:500,000.
Horberg, L., 1950, Bedrock topography of Illinois: Illinois State Geological Survey, Bulletin 73, 111 p.
Horberg, L., 1957, Bedrock surface of Illinois: Illinois State Geological Survey, 1:500,000.
McKay III, E.D., and R.C. Berg, 2008, Optical ages spanning two glacial cycles from deposits of the Ancient Mississippi River, north-central Illinois: Geological Soci­ety of America North-Central Meeting, Abstracts with Programs, v. 40, p. 78.
McKay III, E.D., R.C. Berg, A.K. Hansel, T.J. Kemmis, and A.J. Stumpf, 2008, Qua­ternary deposits and history of the Ancient Mississippi River valley, north-central Illinois: Illinois State Geological Survey, Guidebook 35, 98 p.
Murphy, J.L., 2005, Geologic and hydrogeologic investigation of the buried Ticona Bedrock Valley, in Spring Valley 7.59 Quadrangle: Normal, Illinois, Illinois State University, M.S. thesis, 121 p.
Willman, H.B., 1940, Pre-glacial River Ticona: Transactions of the Illinois State Academy of Science, v. 33, no. 2, p. 172−175.
1
675812131836R 1 WR 1 ET 33 NT 32 N3117322111435360400460460440420480500500520480540560400420440460500520540580380380480480"e"e"e"e"e"k"k"e"k"k"k"e"k"k"k"e"e3934894894884884904884824604504174044034073983923853783633623783783783793803963983954123923943794215105055055004934925075055009056356756256038239538936835235536338137138236736736837337337337337840440540538644934235347347246543942241540337738539037939747484476472400343353418351382406361333422<445<394563587572581563584493<447<557<495<507<463<535<528TICONA BEDROCK VALLEY1/2012 MILES
Figure 2 Bedrock topography of part of the Ticona Bedrock Valley determined by seismic profiles.
"
e"e"k"k"e"k"e"e"k"e"e"e"k"k"k"e"k"k"e"e"e"k"e"k"k"k"k"k"k"k"k"e"k"e"e"e"k"e"e"e"e"e"k"k"k"e"k"e"e"e"e"e"e"e"k"e"e"k"e"e"e"k"e"e"e"e"e"k"k"e"e"e"e"k"e"k"e"e"e"e"e"k"e"k"k"e"k"k"e"e"e"e"e"e"e"e"e"e"k"e"k"k"e"k"e"e"e"e"e"k"e"k"k"k"k"k"e"e"k"k"e"k"k"e"k"k"e"e"k"e"e"k"k"k"k$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T"k"k"e"e"e"e"e"e"e"e"k"e"e"e"e"e"k"e"e"k"e"k"k"e"e"k"e"k"k"e"e"e"e"e"e"e"e"e"k"k"e"e"e"e"e"e"e"e"k"k"k"e"e"e"k"e"e"e"k"e"k"k"e"e"e"k"k"k$T$T$T$0$T"e$T$T$T$T$T$T$T$T$0$0$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T$0$T$0$T$T$T$0$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T$T762493185345216113130192223353312261024273433343218323114352115291625132036283617302628252729768556311829193220302917303132T 12 NT 11 NT 10 NR 9 ER 8 EMILES012
Figure 1 All well and boring locations within the Rome Quadran­gle. On the Rome portion of the main map, to reduce map clutter, only wells and borings that reach bedrock are shown.