Geological-Geotechnical Studies for Siting

Transcription

1 EGN 111 R. L. LANGENHEfM, JR. DEPT. GEOL. UNIV. ILLINOIS 234 N.H. B., 1301 W. GREEN ST. URBANA, ILLINOIS Gelgical-Getechnical Studies fr Siting the Supercnducting Super Cllider in Illinis Preliminary Gelgical Feasibility Reprt J. P. Kemptn, R.C. Vaiden, D.R. Klata P.B. DuMntelle, M.M. Killey and R.A. Bauer Maquketa Grup Galena-Platteville Grups Illinis Department f Energy and Natural Resurces STATE GEOLOGICAL SURVEY DIVISION ENVIRONMENTAL GEOLOGY NOTES

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3 Gelgical-Getechnical Studies fr Siting the Supercnducting Super Cllider in Illinis Preliminary Gelgical Feasibility Reprt J.P. Kemptn, R.C. Vaiden, D.R. Klata P.B. DuMntelle, M.M. Killey and R.A. Bauer ILLINOIS STATE GEOLOGICAL SURVEY Mrris W. Leightn, Chief Natural Resurces Building 615 East Peabdy Drive Champaign, Illinis ENVIRONMENTAL GEOLOGY NOTES

4 Digitized by the Internet Archive in 2012 with funding frm University f Illinis Urbana-Champaign kemp

5 1 INTRODUCTION 1 Supercnducting Super Cllider 1 Prpsed Site in Illinis 2 Gelgic and Hydrgelgic Factrs 3 REGIONAL GEOLOGIC SETTING 5 Surces f Data 5 Gelgic Framewrk 6 GEOLOGIC FRAMEWORK OF THE ILLINOIS SITE 11 General 1 Bedrck 12 Cambrian System Ordvician System Silurian System Pennsylvanian System Bedrck Crss Sectins 18 Bedrck Tpgraphy 19 Glacial Drift and Surficial Depsits 21 Drift Thickness Classificatin, Distributin, and Descriptin f the Drift Banner Frmatin Glasfrd Frmatin Winnebag Frmatin Rbein Silt Wedrn Frmatin Tiskilwa Till Member Maiden Till Member Yrkville Till Member Henry Frmatin Equality Frmatin Cahkia Alluvium ENGINEERING PROPERTIES OF GEOLOGIC UNITS 41 Physical Characteristics f the Drift 42 Physical Characteristics f the Bedrck 43 HYDROGEOLOGY 44 Surce, Mvement, and Availability f Grundwater 44 Water Resurce Distributin 45 POTENTIAL GEOLOGIC CONSTRAINTS 47 Seismicity 47 Subsidence 49 Slumping 49 EVALUATION OF THE GEOLOGY 49 Grundwater as a Getechnical Prblem 49 Cnstructin Prblems 50 Gelgical Features 50 Factrs Related t Surface Cnstructin 50 Factrs Related t Shallw Tunnel Cnstructin 50 Factrs Related t Bedrck Tunnel Cnstructin 51 SUMMARY AND CONCLUSIONS 53 ACKNOWLEDGMENTS 53 APPENDIX 54 REFERENCES 59 GLOSSARY 61

6 1 1 FIGURES 1 Ppulatin distributin-1980, reginal area surrunding Fermi Natinal Acceleratr Labratry '. 2a Principal streams and municipalities in the study area 4 2b Generalized tpgraphy f the study area 5 3 Gelgy f the bedrck surface (mdified frm Willman and Frye, 1970) 7 4 Quaternary (surficial) depsits f Illinis 8 5 Tpgraphy f the bedrck surface f Illinis (frm Willman and Frye, 1970; summarized frm Hrberg, 1950, and thers) 9 6 Drift thickness (frm Willman and Frye, 1970; summarized frm Piskin and Bergstrm, 1967) 10 7 Mraines f nrtheastern Illinis (frm Willman et al., 1975) 1 8a Stratigraphic clumn f bedrck units in nrthern Illinis 13 8b Stratigraphic clumn f drift (Quaternary) depsits in nrthern Illinis 14 9 Areal gelgy f the bedrck surface in study area Elevatin f tp f the Francnia Frmatin in the Cambrian System shwing the majr structural features in nrthern Illinis 16 1 Elevatin f the tp f the Galena Grup where verlain by the Maquketa Shale Grup Thickness f Galena and Platteville Grups Thickness f Maquketa Shale Grup where verlain by Silurian rcks Thickness f Silurian rcks 20 15a Lcatin map fr bedrck crss sectins 21 15b Nrthern E-W crss sectin 22 15c Central E-W crss sectin 23 15d Suthern E-W crss sectin 24 15e Western N-S crss sectin 25 15f Eastern N-S crss sectin Bedrck tpgraphy f study area (after Wickham, 1979) Thickness f glacial drift (cmpiled and mdified frm Grss, 1969; and McCmas, 1969) 28 18a Lcatin f drift crss sectins 30 18b Nrthern E-W crss sectin 31 18c Central E-W crss sectin 32 18d Suthern E-W crss sectin 33 18e Nrth-suth crss sectin Elevatin, base f Tiskilwa Till Member (frm Wickham, 1979) Thickness f Tiskilwa Till Member (frm Wickham, 1979) Surficial gelgy (frm Wickham, 1979) Ptential surficial and buried sand-and-gravel aquifers Preliminary map f hrizntal acceleratin (expressed as percent f gravity) in rck Depth t the tp f the Galena Grup Relative gelgic suitability f the Galena-Platteville Dlmite fr tunneling 52 TABLES 1 Prperties f gelgic units in nrtheastern Illinis 36 2 Grupings f apprximate bearing strengths 41 3 Natural misture cntent 42 4 Dry density weight 42 5 Physical prperties f bedrck units 43 6 Gelgic units as ptential aquifers 45

7 Gelgical-Getechnical Studies fr Siting the Supercnducting Super Cllider in Illinis: Preliminary Gelgical Feasibility Reprt INTRODUCTION The need t prbe the fundamental nature f matter and energy dictates the need fr higher energy particle acceleratrs. With the recent radical imprvement in magnet technlgy, it has becme pssible t build an acceleratr with an energy f abut 20 trillin electrn vlts (TeV). The preliminary design and cst estimates fr a Supercnducting Super Cllider (SSC) are nw being prepared by physicists frm the natinal labratries and the university cmmunity. At the Fermi Natinal Acceleratr Labratry (Fermilab) in Batavia, Illinis, the wrld's mst advanced, high-energy acceleratr has just begun peratin: the Tevatrn the first t use supercnducting magnets has accelerated prtns nearly t its design energy f 1 TeV. The SSC prject is a natural extensin f Fermilab, which culd be used as an injectr fr the prpsed facility. The design fr the Supercnducting Super Cllider is still evlving, but the current plan is t cnstruct a ring, circular t elliptical (including tw straight segments), rughly 20 t 30 miles (32 t 48 km) in diameter, and ideally lying in a flat plane althugh ne r tw bends are technically pssible. Clearly, the SSC wuld extend well beynd the present Fermilab brders. Althugh the use f the Tevatrn as an injectr fr the SSC wuld save a significant amunt f mney, the suitability f the tpgraphy and gelgy f the Fermilab envirns must be demnstrated. A preliminary review f the lcal gelgical literature (Husn in Slansky, 1983) indicates n majr restrictins t placement f the ring in that regin. In June 1983, the Illinis State Gelgical Survey (ISGS) was asked t determine site suitability frm a gelgical perspective. It was agreed that the wrk wuld cnsist f fur phases: (1) cllecting and rganizing existing gelgical data needed t select pssible sites; (2) investigating a selected regin near Fermilab t lcate the mst suitable circular crridr; (3) verifying predicted cnditins within the crridr by drilling test hles, and presenting the results in a final gelgical reprt; and (4) cntinuing t act as gelgical cnsultants during the site selectin prcess. This reprt cnstitutes phase 1 : a preliminary cmpilatin f existing gelgic maps, reprts, and ther readily available gelgic data. Maps and crss sectins have been specifically prepared t fcus n the gelgic units relevant t ring siting; gelgic units have been described and characterized t a gelgically and ecnmically practical depth (abut 600 ft [180 m] ). These data prvide a prvisinal base fr determining verall gelgic suitability fr lcating an acceleratr up t 30 miles (48 km) in diameter. The reprt indicates prblem areas as well as areas and gelgic units that appear mst suitable fr the ring. Supercnducting Super Cllider The SSC is a scientific instrument fr explring the basic structure f nature. In a sense, it's a giant micrscpe fr fcusing n the building blcks f nature and fr revealing the frces that hld the universe tgether. Enrmus energy is required t bserve bjects at subatmic level. The SSC wuld accelerate prtns t 20 trillin electrn vlts (TeV). Althugh this energy is nt large n an abslute scale (abut the same as a falling raindrp), it is cncentrated int the space SSC: PRELIMINARY GEOLOGICAL FEASIBILITY REPORT 1

8 ccupied by a single prtn. This cncentratin creates higher penetrating pwer upn impact, just as a rifle bullet penetrates deeper than a larger bject with the same energy. A head-n cllisin f tw mving bjects enhances the effect. In fact, this is hw a 20- TeV clliding beam acceleratr wuld perate: tw beams f high-energy particles wuld cllide at nearly the speed f light. By bserving the cllisins, physicists will be able t examine particle structure at a size and energy far beynd present reach. High-energy cncentratin r density als means high temperatures even greater than thse f stars. Frm ther bservatins, astrnmers tell us that the universe behaves as if its parts are expanding frm sme primeval explsin. Only near the time f this hypthesized "Big Bang" f creatin wuld temperatures have been as high. The SSC will simulate the cnditins f high density and temperature ccurring during the "Big Bang." Because it is such a large step beynd ur existing acceleratrs, the SSC may reveal an entirely new range f phenmena. At present, the natin's lead in high-energy physics greatly depends n the existing 1-TeV acceleratr at Fermilab. T maintain the lead, the High Energy Physics Advisry Panel recmmended in July 1983 that the Office f Energy Research f the U.S. Department f Energy initiate research t develp and build an acceleratr with abut 20 times the energy f Fermilab's Tevatrn. Varius designs fr a supercnducting super cllider are nw under investigatin. The exact size f the SSC has nt yet been determined. It will depend n the strength f the magnets needed t keep the particles mving in a circular rbit. The supercnducting magnets in the Tevatrn have a peak magnetic field f 4.5 Tesla (T). If magnets with similar strength are used in the SSC, that wuld increase the scale f the Tevatrn's 1-km radius by a factr f 20, the rati f their energies. If strnger magnets can be develped, hwever, the size f the SSC will be reduced prprtinally. Research and develpment n magnet technlgies will cntinue fr the next year r tw befre a decisin is made n the strength f the SSC magnets. The lcatin f the SSC will be decided n the basis f a natinal cmpetitin, similar t the prcess used fr deciding t lcate Fermilab in Batavia. Several states ther than Illinis have already shwn interest. Undubtedly, many will submit sites fr cnsideratin. Prpsed Site in Illinis T use the Tevatrn as an injectr, the SSC must be lcated at Fermilab. It wuld extend well beynd the present site bundaries, s it wuld need t be a benign, unbtrusive neighbr t nearby cmmunities. In general, issues invlving the siting f the acceleratr range frm gegraphical t human. Gegraphical /natural Tpgraphic relief Surface materials: types and prperties Bedrck strength, stability Surface water drainage Grundwater flw patterns Water quality and quantity Weather cnditins Scial /human Ppulatin density Electrical pwer Transprtatin netwrk Industrial, business, and labr supprt Husing, schls, recreatinal facilities Land use and wnership Site flexibility fr future ptins T minimize the human and eclgical impact f cnstructing and perating the SSC, as well as keep the csts f purchasing land as lw as pssible, it was decided t investigate the area west f Fermilab. The ppulatin density is cnsiderably lwer in that directin (fig. 1). Recent studies (Baker et al., 1983; Husn, 1983) suggest this area meets mst f the scial requirements and prbably mst f the engineering and cnstructin requirements (Slansky, 1983). Tw pssible scenaris have been suggested: Husn (1983) describes a ring west f the Fx River with an extractin line (tunnel) frm the Tevatrn under the river; the ring ILLINOIS STATE GEOLOGICAL SURVEY EGN 111

9 WinnebiH) 1 ROCKFOR Figure 1. Ppulatin distributin 1980, reginal area surrunding Fermi Natinal Acceleratr Labratry. (Numbers represent nearest 1000.) wuld be mainly in De Kalb and Kane Cunties but intersect a small part f nrthern Kendall Cunty. This scenari leaves pen the chice f ring depth. After crssing the river, the beam culd either be directed dwnward and injected int a ring placed at sme depth, r it culd be steered upward and injected int a ring near the land surface. The ther scenari wuld have the 20-TeV ring pass under the Fermilab site. In that case, the beam extracted frm the Tevatrn wuld be directed dwnward. Since the 20-TeV ring wuld have t pass under the Fx River, this ptin dictates a minimum depth. The regin selected fr this study cvers the areas invlved in bth scenaris. As shwn in figures 2 and 3, the area extends abut 6 miles east, 20 miles nrth, 20 miles suth, and 40 miles west f Fermilab. It includes a ttal f 36 twnships; each twnship is 6 miles n a side, r 36 square miles. The ttal area cvered by the base map (fig. 2) is 1,296 square miles. Gelgic and Hydrgelgic Factrs Any site selected fr the acceleratr ring must be gelgically suitable bth fr the cnstructin and the lng-term peratin f the SSC. Three designs fr cnstructin have been cnsidered: a shallw trench at the surface (cut-and-cver technique), a shallw tunnel in glacial drift, and a deep tunnel in bedrck. SSC: PRELIMINARY GEOLOGICAL FEASIBILITY REPORT

10 R8t T42N T41N T40N T39N T38N T37N Figure 2a. Principal streams and municipalities in the study area. As a result, the gelgic materials and their hydrgelgic prperties must be evaluated frm the surface t a depth f several hundred feet. Primary factrs t cnsider include thickness, distributin, and character f glacial drift and rck units, frm the surface t abut 600 feet deep; stability f the earth's crust, including fractures and faults; seismicity: the ptential effects f earthquakes: stability and strength f bedrck fr tunnel cnstructin; sufficiency f supplies and prtectin f grundwater resurces. ILLINOIS STATE GEOLOGICAL SURVEY EGN 111

11 R2E R3E R4E R5E R6E )E KALBIkANI R7E Cntur interval 50 feet Figure 2b. Generalized tpgraphy f the study area. REGIONAL GEOLOGIC SETTING Surces f Data Cnsiderable gelgic data is available fr the regin cvered in this study. The infrmatin summarized in this reprt is sufficient t prvide a preliminary assessment f the regin as a site fr the lcatin f the SSC. Surces include lcal and reginal gelgic studies cnducted by the ISGS and made available in its reprts, including graduate theses; lgs and samples f water wells and engineering brings in the files f the ISGS; recrds f subsurface drilling and sampling prgrams cnducted fr water resurces studies f nrtheastern Illinis; reginal reprts and infrmatin n seismic activity, crustal stability, and earthquake histry. A few recent, specific studies and data sets prvide the backbne f the gelgic and hydrgelgic maps and discussins presented here: studies f the bedrck by Buschbach (1964), SSC: PRELIMINARY GEOLOGICAL FEASIBILITY REPORT

12 Hughes, Kratz, and Landn (1966), Willman (1973), Willman and Klata (1978), and Klata and Graese (1983); reprts n the glacial depsits by Kemptn (1963, 1966), Kemptn and Hackett (1968a, 1968b), Kemptn and Grss (1971), Grss (1969), Landn and Kemptn (1971), Wickham (1979), Wickham and Jhnsn (1981), and Brssman (1982); and ther reginal reprts by Piskin and Bergstrm (1967, 1975), Willman and Frye (1970), Willman etal. (1975), and Willman (1971). Cunty and reginal studies relating gelgy t land-use planning include Grss (1970) fr De Kalb Cunty, Kemptn et al. (1977) fr nrtheastern Illinis, and Gilkesn and Westerman (1976) fr Kane Cunty; these include discussins f aquifer distributin depsits. Gelgic Framewrk and engineering characteristics f surficial The fllwing summary places the gelgy f the prpsed nrthern Illinis site int reginal perspective and presents sme basic gelgic principles and definitins. The generalized gelgy f Illinis is depicted in figures 3 and 4. Bedrck materials are generally categrized as (1) the Precambrian granite, which frms the basement (underlying the frmatins shwn n fig. 3); (2) the indurated sedimentary rck successin (shale, sandstne, limestne, and dlmite) f the Cambrian thrugh Pennsylvanian Systems; and (3) the nnindurated, relatively sft Cretaceus and Tertiary depsits. The Quaternary depsits (fig. 4), which include thse materials depsited by the cntinental glaciers, are referred t as verburden, uncnslidated materials, r glacial drift. The terms glacial drift r drift are used in this reprt. The sedimentary rck successin has been reginally warped and tilted, generally dipping tward sutheastern Illinis where it is up t 15,000 feet thick in the center f the Illinis Basin. The yungest bearck, cmpsed primarily f shale and siltstne with sme sandstne and relatively thin beds f limestne and dlmite, cvers a large area f nrthcentral, central, and suthern Illinis. Older rcks are at the bedrck surface in nrthern Illinis and prtins f western and suthwestern Illinis. The distributin pattern f these rcks is als cntrlled by the cnfiguratin and elevatin f the bedrck surface (fig. 5). The verlying glacial drift frms a cap f variable thickness ver the bedrck thrughut mst f the state (fig. 6 and Piskin and Bergstrm, 1975). Glacial depsits are usually thickest where they fill valleys that frmed n the bedrck surface, but als may be relatively thick in end mraines (figs. 4 and 7) that mark the margin f sme glacial advances. The Cretaceus and Tertiary rcks are restricted t small areas f western and suthern Illinis (fig. 3). They are cmpsed primarily f bedded clays, silts, sands, and gravels. Since they are generally absent in nrthern Illinis, they will nt be discussed further. The glacial depsits (fig. 4) can be bradly categrized either (1) as materials depsited directly frm the melting glacier, a mixture f pebbles and cbbles in a matrix f clay, silt, and sand (till); r (2) as materials carried ut frm the glacier by the meltwater and redepsited alng meltwater rivers r in lakes. Sand and gravel (utwash) was depsited by the rapidly flwing meltwater rivers, whereas the silt and clay (lacustrine depsits) settled ut in quiet-water lakes and pnds. Als present are windblwn sand and silt recent river depsits (alluvium), slpewash (clluvium), and peat and muck. Of these depsits, glacial till and utwash predminate. Glacial tills can be identified by dminant grain size and mineralgic characteristics. Where the bedrck is near the surface, nly ne till may be present. In the thicker drift areas, several tills as well as utwash and lacustrine depsits may be present. A mre cmplete discussin f the glacial depsits f Illinis is given by Piskin and Bergstrm (1975) and by Willman and Frye (1970). The Handbk f Illinis Stratigraphy (Willman et al., 1975) summarizes the distributin f all gelgic materials in Illinis. (less), ILLINOIS STATE GEOLOGICAL SURVEY EGN 111

13 mi 80 km 4P Fermilab Pleistcene and Plicene nt fifi r&'l TERTIARY 136 :&:: CRETACEOUS 315 ~ ft'! M PENNSYLVANIAN Bnd and Mattn Frmatins Includes narrw belts f lder frmatins alng La Salle Anticline PENNSYLVANIAN Carbndale and Mdest Frmatins PENNSYLVANIAN Caseyville, Abbtt, and Spn Frmatins MISSISSIPPIAN Includes Devnian in Hardin Cunty DEVONIAN Includes Silurian in Duglas, Champaign and western Rck Island Cunties r S HSU ^^ *>^~~ SILURIAN Includes Ordvician and Devnian in Calhun Greene, and Jersey Cunties RDOVICIAN CAMBRIAN Des Plaines Disturbance-Ordvician t Pennsylvanian Fault Figure 3. Gelgy f the bedrck surface (mdified frm Willman and Frye, 1970). SSC: PRELIMINARY GEOLOGICAL FEASIBILITY REPORT

14 Hlcene Wiscnsinan Sangamnian lllinian Present- 10,000 yrs 10,000-75,000 yrs 75, ,000 yrs 125, ,000? yrs AGE UNIT Hlcene _ _ - _ - J Cahkia Alluvium Wiscnsinan Wiscnsinan i Henry Frmatin cmbined; alluvium, windblwn sand, and sand and gravel utwash. Peria Less and Rxana Silt cmbined windblwn silt mre than 6 meters (20 ft) thick. Equality Frmatin; silt, clay, and sand in glacial and slack-water lakes Wedrn and Trafalgar Mraine Frmatins cmbined; Grund glacial till with sme I J temm mraine ^^ grave and si t hi Wiscnsinan y////j Winnebag and Glasfrd Frmatins and <t/////i cmbined; glacial till with sme sand lllinian gravel, and silt; age assignment f sme units is uncertain. lllinian px^vil Glasfrd Frmatin; glacial till with sme sand, '. - '.'.'.' w A gravel, and silt. Teneriffe Silt, Pearl Frmatin, and Hagarstwn Member' I f the Glasfrd Frmatin cmbined; lake silt and clay, utwash sand, gravel, and silt. Pre-lllinian CX7Q Wlf Creek Frmatin; glacial till with gravel, sand, PWS and silt. Bedrck $2 Figure 4. Quaternary (surficial) depsits f Illinis. ILLINOIS STATE GEOLOGICAL SURVEY EGN 111

15 m km Elevatin abve sea level (ft) > [ J I I <200 Figure 5. Tpgraphy f the bedrck surface f Illinis (frm Willman and Frye, 1970; summarized frm Hrberg, 1950, and thers). SSC: PRELIMINARY GEOLOGICAL FEASIBILITY REPORT

16 m km Thickness (ft) <50 j >400 Figure 6. Drift thickness (frm Willman and Frye, 1970; summarized frm Piskin and Bergstrm, 1967). 10 ILLINOIS STATE GEOLOGICAL SURVEY EGN 111

17 V./V! B WOODFORDIAN MORAINES Figure 7. Mraines f nrtheastern Illinis (frm Willman et al., 1975). GEOLOGIC FRAMEWORK OF THE ILLINOIS SITE General In De Kalb and Kane Cunties and parts f adjacent cunties, the drainage, tpgraphy, and glacial drift materials were largely prduced by ersin and depsitin by glacial ice and running water. The layered bedrck lies belw the glacial drift at depths generally ranging frm 50 t 300 feet. Lcally in sutheastern De Kalb Cunty, these materials are mre than 500 feet thick; elsewhere, as alng parts f the Fx River valley, they are less than 50 feet thick, with bedrck ccasinally expsed in quarries, alng streams, and in radcuts. SSC: PRELIMINARY GEOLOGICAL FEASIBILITY REPORT 11

18 Figure 8a shws the classificatin and successin f the bedrck; figure 8b shws the classificatin and successin f drift units present in the study area. These depsits are classified bth as time-stratigraphic units (System, Series, Stage) and as rck-stratigraphic units (Grup, Frmatin, Member). The time-stratigraphic classificatin relates ages f rcks frm area t area and serves as a basis fr gelgic time classificatin. The rckstratigraphic classificatin differentiates rcks accrding t lithlgy r type f rck r material. In this study, rck stratigraphy is emphasized. Bedrck Bedrck within the area cnsists f Cambrian, Ordvician, and Silurian strata that have a cmbined maximum thickness f apprximately 4000 feet (1200 m). These sedimentary rcks rest uncmfrmably n a basement f Precambrian granite (fig. 8a). The areal distributin f the bedrck frmatins directly belw the glacial drift is shwn in figure 9. Althugh numerus frmatinal and subfrmatinal units are recgnized in these strata, the gelgic map shws nly the fllwing divisins: the Cambrian System; fur rck units in the Ordvician System (the Prairie du Chien Grup, the Ancell Grup, the cmbined Galena and Platteville Grups, and the Maquketa Grup); and the Silurian System. The distributin f bedrck units in Kane, Kendall, and De Kalb Cunties is mainly the result f ancient tectnic activity n the Wiscnsin Arch and Sandwich Fault Zne (fig. 10) and f pstdepsitinal ersin. The Wiscnsin Arch is a brad, psitive (high) structural feature that extends frm nrthern Wiscnsin int nrthernmst Illinis. In Illinis the arch has gentle slpes, averaging apprximately 100 feet (30 m) in 5 t 10 miles (8 t 16 km). The arch was truncated during a lng perid f ersin that expsed the lder rck units at the bedrck surface alng the crest f the arch. Within the study area, the Platteville and Galena Grups crp ut beneath the yunger Maquketa Shale Grup alng a highly irregular bundary, which resulted largely frm deep preglacial ersin f valleys int the bedrck surface. In parts f western De Kalb Cunty and eastern Ogle Cunty preglacial valleys are entrenched in rcks as ld as the Ancell Grup. Farther dwn the flank f the arch in eastern Kane Cunty the Maquketa crps ut beneath Silurian dlmite frmatins alng an equally irregular bundary. The Sandwich Fault Zne is a narrw zne (0.5 t 2 miles wide) f nearly vertical faults extending nrthwestward frm Will Cunty thrugh Kendall and De Kalb Cunties t Ogle Cunty (Klata et al., 1978). The fault zne is characterized by numerus faults, with vertical displacements ranging frm a few inches t a few hundred feet. It has a maximum cumulative displacement f abut 800 feet dwn t the nrth near the twn f Sandwich in sutheastern De Kalb Cunty. The fault zne brings Cambrian and lwer Ordvician rcks in juxtapsitin with the Galena-Platteville and Ancell Grups in suthern De Kalb Cunty. Like the Wiscnsin Arch, the uplifted side f the fault zne has been beveled by ersin and has n tpgraphic expressin at the bedrck surface. Because the tpgraphy f the area is subdued and glacial drift cvers much f the bedrck, the fault zne is expsed at very few lcalities. Much infrmatin n the nature, age, extent, and magnitude f faulting is based n subsurface data. Gelgic relatinships suggest that the majr mvements in the fault zne tk place abut 300 millin years ag (Klata, Buschbach, and Trewrgy, 1978; Klata and Buschbach, 1976). It shuld be nted that there has been n displacement in the Sandwich Fault Zne r any ther surficial fault in Illinis during histrically bserved earthquakes (Heigld, 1972). Cambrian System. Cambrian rcks in the area include the Mt. Simn Sandstne (ldest), Eau Claire Frmatin, Irntn-Galesville Sandstne, Francnia Frmatin, Ptsi Dlmite, and Eminence Frmatin (fig. 8a). The Mt. Simn Sandstne is mstly white t pink, carse grained, prly srted sandstne ranging frm 1700 t 2600 feet thick. The Eau Claire Frmatin cnfrmably verlies the Mt. Simn and cnsists f sand- 12 ILLINOIS STATE GEOLOGICAL SURVEY EGN 111

19 LU r~ c > CO CO LU CC LU CO Grup Frmatin Graphic Lg Quaternary depsits abve Descriptin r D I CO Dlmite, fine grained, cherty.c c c ' -> Maquketa Shale and interbedded dlmite < > Q r O < _l _ < IE CJ c r T3 CD C r O Galena- Platteville Ancell Glenwd^ St. Peter Ss Prairie du Chien T^& S 3 Dlmite, /. / ^Z ~ 2 =P-T- ::.... ;.'.. JU.*. '.»'!.! very fine t medium grain, cherty Sandstne, fine t medium grain, well srted; dlmitic, prly srted at tp Dlmite, cherty; sandstne, siltstne, and shale Eminence Ptsi ; / /;y ;y:l^;/ *zzz Dlmite, fine t medium grain, sandy; cntains litic chert Dlmite, fine grain 7 T Z < r 00 < Francnia Irntn- Galesville Jv : - ' ; : \-;JU;-;. ;.// :/:' i Sandstne, fine grain, glaucnitic Sandstne, dlmitic, fine t medium grain Eau Claire Sandstne, siltstne, shale, and dlmite; glaucnitic Mt. Simn ^-^v ' :'>:.yy-;. ;!':. Sandstne, carse grained, prly srted PRECAMBRIAN / ^ / i / / ^ \, \ ^ Granite, red Figure 8a. Stratigraphic clumn f bedrck units in nrthern Illinis. SSC: PRELIMINARY GEOLOGICAL FEASIBILITY REPORT 13

20 1 V " LU < i- c Frmatin Member Graphic Lg Descriptin Cahkia Alluvium sand, silt, and clay depsited by streams Grayslake Peat and muck, ften interbedded with silt and clay Richland Less windblwn silt and clay Equality Lake depsits silt and clay, sme sand Henry Outwash sand and gravel depsited by glacier meltwater in valleys and hills O <_> CO Yrkville Till yellwish brwn t gray silt and clay lam Maiden Tiskilwa '/,\ / /. _L.\... Till yellwish brwn t brwnish gray lams t sandy lam till; lcally extensive basal sand and gravel Till reddish brwn/grayish brwn lam, generally unifrm Rbein.' Silt, sandy silt, si It v day, rganic rich; buried sil, alluvium r bg depsits Winnebag Sand and gravel, discntinuus Sangamnian ' * ' i \ \ ^ * r ' < O Winnebag r Glasfrd Till, sand and gravel, lacustrine silt and clay; 8 till members recgnized reginally; sand and gravel and lacustrine cncentrated in bedrck valleys Mj-:'. '..%4. ' * : ; >i Sand and gravel, basal materials in deeper bedrck valleys Bedrck ISG > 1984 Figure 8b. Stratigraphic clumn f drift (Quaternary) depsits in nrthern Illinis. stne, siltstne, shale, and dlmite; the Eau Claire is 350 t 450 feet thick in the area. Fine- t medium-grained, well srted sandstne up t 220 feet thick characterizes the verlying Irntn-Galesville Sandstne. The Francnia Frmatin cnsists f fine-grained, dlmitic sandstne characterized by abundant scattered fine grains f glaucnite; the Francnia is frm 75 t 150 feet thick. Because it is a surface f relatively lw ersinal r depsitinal relief and can be easily recgnized, the tp f the Francnia is a useful structural hrizn (fig. 10). Overlying the Francnia is the Ptsi Dlmite, which cnsists f fine-grained dlmite cntaining drusy quartz; the Ptsi is apprximately 130 feet (39 m) thick in the area. It and the verlying Eminence Frmatin ccur at the bedrck surface n the suth side f the Sandwich Fault Zne in suthern De Kalb Cunty, the Eminence, which is the uppermst Cambrian frmatin in the area, is fine-t-mediumgrained dlmite that cmmnly cntains sand and litic chert; the Eminence is abut 100 feet (30 m) thick. 14 ILLINOIS STATE GEOLOGICAL SURVEY EGN 111

21 T39N " Silurian Ordvician Maquketa Platteville Galena ' ;. ';.* ' :ii:::ij] Ancell Prairie du Chien Cambrian 6 mi Figure 9. Areal gelgy f the bedrck surface in study area. Ordvician System. The Prairie du Chien (ldest), Ancell, Galena-Platteville, and Maquketa Grups cnstitute the Ordvician rcks in the area (fig. 8a). All these stratigraphic units ccur at the bedrck surface in the area f the prpsed acceleratr ring. The Prairie du Chien Grup cnsists primarily f cherty dlmite and interbedded sandstne but als cntains sme siltstne and shale. It ranges frm a featheredge t abut 400 feet thick. The Ancell Grup, which cnsists f the St. Peter Sandstne and Glenwd Frmatin, uncnfrmably verlies the Prairie du Chien Grup. The St. Peter is a pure, generally white, fine- t medium-grained, runded, well srted, friable sandstne between 150 and 250 feet thick. It is verlain by the Glenwd, a highly variable frmatin cnsisting f prly srted sandstne, silty dlmite, and green shale, all lcally up t 75 feet thick. The Galena and Platteville Grups (fig. 8a) cnsist f pure, partly cherty dlmite with a cmbined thickness f apprximately 350 feet where they are verlain by the Maquketa Shale Grup. These rcks ccur at the bedrck surface thrughut a large part f western SSC: PRELIMINARY GEOLOGICAL FEASIBILITY REPORT 15

22 > n E (0 O LL c «- 0> " 16 ILLINOIS STATE GEOLOGICAL SURVEY EGN 111

23 R2E T42N T41N T40N T39N T38N T37N Cntur interval 50 feet Figure 11. Elevatin f the tp f the Galena Grup where verlain by the Maquketa Shale Grup. De Kalb Cunty (Willman and Klata, 1978). The upper 60 t 80 feet f Galena strata are chert-free, prviding an imprtant surce f high-quality aggregate in nrthern Illinis. Like the Francnia Frmatin the tp f the Galena is a widespread, easily recgnized, mappable surface (fig. 11) that reflects the structural mvements that have taken place since the Galena was verlain by the Maquketa Shale Grup. Because f the numerus wells that have penetrated the Galena, it is the mst reliable structural datum within the study area. West f the limit f Maquketa strata, the Galena and Platteville are deeply dissected by preglacial valleys (fig. 12). In parts f central De Kalb Cunty the Galena and Platteville are cut ut entirely by the Try Bedrck Valley. The Maquketa Grup, which verlies the Galena-Platteville, cnsists f shale and argillaceus dlmite that ranges in thickness frm 100 t 200 feet (fig. 13). As a result f being deeply truncated by pre-silurian ersin, the precise thickness at any given lcality cannt be predicted with cnfidence (Klata and Graese, 1983). In nrthern Kane and De Kalb Cunties the Maquketa cnsists primarily f argillaceus dlmite. This grades suthward t mainly shale in Kendall Cunty. In the area f Fermilab the Maquketa can be expected t be apprximately 130 feet thick, cnsisting primarily f dlmite and dlmitic shale. SSC: PRELIMINARY GEOLOGICAL FEASIBILITY REPORT 1 7

24 T42N T41N T40N T39N T38SN T37N Cntur interval 50 feet t west f the Maquketa eijsinal edge Cntur interval 25 feet t east f trie Maquketa ersinal edge Figure 12. Thickness f Galena and Platteville Grups. Silurian System. The Silurian System uncnfrmably verlies the Maquketa in nrthern Illinis. Where the Maquketa is deeply dissected by pre-silurian ersin, the Silurian strata tend t be shale and very argillaceus dlmite. Cnversely, where pre-silurian ersin was minimal, the verlying Silurian strata tend t be relatively pure, cherty dlmite. The Silurian thickens frm an ersinal featheredge in Kane and Kendall Cunties (fig. 14) t as much as 300 feet t the east in the Chicag area. It is apprximately 140 feet thick beneath Fermilab. Pennsylvanian System. Pennsylvanian sandstne, shale, and cal may be present in a few small scattered utliers (islated depsits) within the area. These rcks cmmnly ccur in crevices, slutin-cllapsed structures, and lenticular remnants in depressins n the surface f Silurian and Ordvician carbnate rcks. Bedrck Crss Sectins Figures 15a t 15f, a lcatin map and series f crss sectins, shw the stratigraphic relatins in the upper 300 feet r s f the bedrck within the study area. They als shw the relative thickness f verlying glacial drift and the elevatin f the land surface. The ttal 18 ILLINOIS STATE GEOLOGICAL SURVEY EGN 111

25 Cntdur interval 20 feet Figure 13. Thickness f Maquketa Shale Grup where verlain by Silurian rcks. depth f each cntrl well is marked beneath each cunty lcatin. Knwing the thickness f the bedrck units, it is pssible t determine apprximately what frmatin the well was finished in. Particularly ntable features n these crss sectins are the bedrck valleys, facies relatins within the Maquketa Shale Grup (figs. 15b, c, and f), structural relief as seen n the tp f the Galena-Platteville Grups, Sandwich Fault Zne (figs. 15d and e), and ersinal featheredge f the Maquketa and Silurian rcks (figs. 15b, c, and f). Bedrck Tpgraphy The bedrck tpgraphy map (fig. 16) was derived primarily frm well data and bedrck utcrps. The map is a slightly mdified versin f ne prepared by Wickham (1979), which was als a mdificatin f maps prepared by R. H. Gilkesn (unpublished) and Kemptn (McGinnis et al., 1963). The Kendall Cunty prtin f the map was prepared fr this reprt frm available well lgs. The bedrck surface is cut by deep bedrck valleys, which generally trend nrth-suth r east-west. The Try, Rck and "Newark" Bedrck Valleys (fig. 16) are the majr early Pleistcene drainage features in the area. The deep, steep-sided, drainageways that cut int the bedrck were tributaries t the ancient Mississippi Valley system (Hrberg, 1950). SSC: PRELIMINARY GEOLOGICAL FEASIBILITY REPORT 19

26 T42N T41N T40N T39N T38N T37N mi Cntur interval 50 feet Figure 14. Thickness f Silurian rcks. The Rck and Try Bedrck Valleys are parallel t each ther alng the western edge f the study area. They jin t frm the Paw Paw Valley in sutheastern Lee Cunty. The "Newark Valley," heading in nrtheastern Kane Cunty, extends acrss the suthern part f the study area and jins the Paw Paw Valley in Lee Cunty. It was frmerly thught t extend suthward under Newark (Kendall Cunty). A brad, shallw tributary trends nrtheast-suthwest acrss the center f the area and jins the "Newark Valley" in suthernmst De Kalb Cunty. Elevatins f bedrck (fig. 16) range frm less than 450 feet in the deepest prtins f the Try and Rck Bedrck Valleys t mre than 800 feet in nrthern Kane Cunty. Away frm the bedrck valleys the average elevatin f the bedrck uplands is between 700 and 800 feet, except in the suthernmst prtins f Kane and De Kalb and in Kendall Cunties where it ranges frm 550 t 650 feet. Bedrck utcrps are present in nrthwestern De Kalb Cunty, and alng the Fx River. The general slpe f the bedrck upland surface is abut 5.5 feet per mile frm westnrthwest t east-sutheast and is apprximately the same as the reginal dip f the bedrck structure. 20 ILLINOIS STATE GEOLOGICAL SURVEY EGN 111

27 i R2E R3E R5E R6E DE KALBTkANE R7E Figure 15a. Lcatin map fr bedrck crss sectins. Glacial Drift and Surficial Depsits The early cntinental glaciers that entered nrthern Illinis encuntered a bedrck surface that had been erded t essentially its present cnfiguratin. As each glacier cvering the regin melted, it left a capping debris ver the surface. Drainage frm the melting glaciers generally carried sand and gravel int the existing valleys, while the glaciers depsited layers f till ver the uplands. These successive layers f drift almst ttally masked the bedrck surface. Over mst f the area, till was depsited in relatively flat layers (grund mraine) that were ften mdified by later glacial and pstglacial prcesses. Where the glacial terminus remained relatively statinary, large arcuate ridges (end mraines) built up (fig. 7). Sme end mraines are nn-hmgeneus cllectins f material that may have inclusins f sand and gravel. The verall internal structure may be distrted by slippage alng shear planes. Many are similar t the end mraines cmpsed f Tiskilwa Till (Blmingtn Mrainic System, fig. 7), which exhibit cnsiderable unifrmity thrughut their thickness (Wickham, 1979). During the last stage f glaciatin, the yungest glaciers that reached the eastern and nrthern prtins f the regin prduced extensive ersin by meltwaters that appeared SSC: PRELIMINARY GEOLOGICAL FEASIBILITY REPORT 21

28 E 00, c g s u i j in i in t 9A8 ess ueauj aaqe uueaaig -T O T * tt n 1 u. z 22 ILLINOIS STATE GEOLOGICAL SURVEY EGN 111

29 1 1 ^ 2 40N- 20 ALB 1253 N. 1 T. O J LU si D CD ( > 1.3 m C7> u K \ / / '. '.".' ".'.'.' V.'\. - 1 i I i 1 I r > If) ( ) IT) in u-> Si mm O > c ) 00 CD r- r«10 CO in in T *r n n 8Ad eas ueaw aaqe uijraaig 6? in lu u. SSC: PRELIMINARY GEOLOGICAL FEASIBILITY REPORT 23

30 r > ^ H F 2 </) D UJ O CD _l 2 p- in cm.o) < G / a> LU j: * >l- r ~ i - i l 1 1 i 1 I O S LO in LO m in * O) > CO 00 r- l~- t 10 IT) IT) 3A9 eas ue9lu aaqe ujieaaig ^auz l nej qi/wpues -VS. O; "; <*> in ri LU Lfi r -? 3 - CJ) U. C/) 24 ILLINOIS STATE GEOLOGICAL SURVEY EGN 111

31 ' c:^:2 : : : P':5.":': > a CO ' CD K D Wl z t- \ O Dm? O ^ Z?s < d) rat- 111 C (O 5 SE «Q 1 C r. O CO. in 5 in z «~ c -' 1 i i 1 i O ID m LD in in CT> a> c t t> l>> t (0 IT) O in m «i b 5 1 m M O PJ 3A9 eas ueaw SAqe uiiea3 g 1 CO 3 K iz g SSC: PRELIMINARY GEOLOGICAL FEASIBILITY REPORT 25

32 2 OM» Duj 5 S 41 1: _i r» = in jnlffl Q. >- fc t- 2 <3~ 3in» ^J^i; <-> OlO. r^ c -I CO c ^se z T CD c > J3 > < I- in.- Zuj JJ OCO *- r u COC«*" m *? <E z SO > 9 I- 3 f ^ ai <r <u Ozf<i uj z *~ 3 ZS cq 00 0> c > r- 2 *- 3 c m c Oz«S > 8ciS -J ' *~ < a> ^ V ^Z > - (- "> ^ 2 d 0) Oz (N c UJ ' tn r < W 5 D H c > > N _l UNT -8E feet rm Oz» f^u"- in ^t QJ CO H CO 2lil 00 Ozz«<OOt- CO * > 1- I»8 8 O in CD in tn 9A9 ess ueaw 9Aqe u!ie/\a 3 r O r 26 ILLINOIS STATE GEOLOGICAL SURVEY EGN 111

33 i i i i i i R3E R6E R7E R9E T42N T41N T40N T39N T38N T37N 'S' Elevatin abve mean sea leve Cntur interval 50 feet mi Figure 16. Bedrck tpgraphy f study area (after Wickham, 1979). t have remved sme earlier drift, lcally erding t the bedrck surface as alng the Fx River valley. During the last 12,000 years, recent (Hlcene) alluvia! and ther sediments have been depsited n the develping mdern surface (fig. 8b). Drift Thickness. The drift thickness map (fig. 17) was derived frm several surces. The De Kalb prtin f the map was riginally drafted by McCmas (1969, unpublished) by cmparing surface elevatin with bedrck tpgraphy as established at that time. Wells frm which the bedrck data were drawn were field checked in the 1960s. Mdificatins were made during the curse f this study using recent cnfirmed and uncnfirmed data. A Kane Cunty map was prepared by Grss (1969) and redrawn using data prvided by R. H. Gilkesn. Minr changes were made alng the Kane-De Kalb cunty line fr this study. Further map mdificatins, particularly in De Kalb Cunty, are cntemplated fr the next phase f the study and fr a current study f the water resurces f Kane Cunty. The Kendall Cunty drift thickness map was prepared fr this reprt and will als be further mdified. Since the grund surface tpgraphy is relatively flat, drift thickness generally mirrrs bedrck tpgraphy ver much f the area. Because f the steep bedrck valley walls, SSC: PRELIMINARY GEOLOGICAL FEASIBILITY REPORT 27

34 R9E f42n r4iim T40N T39N T38N T37N 0,2,4,6 m Cntur interval 50 feet Figure 17. Thickness f glacial drift (cmpiled and mdified frm Grss, 1969; and McCmas, 1969). drift thickness may change enrmusly within a very shrt distance. Areas f lwest bedrck elevatin generally have the thickest drift, while the reverse is true in areas f high bedrck elevatin. Exceptins ccur in nrtheastern Kane Cunty, where the Mareng Mraine reaches elevatins f greater than feet, primarily due t the cmbined effects f the great thickness f the Tiskilwa Till and the high bedrck elevatin. Drift thickness varies frm zer t greater than 500 feet. The greatest thickness (300 t 500 feet) ccurs in the Try Valley in the suthwest crner f De Kalb Cunty and nrthward alng the valley. Thicknesses between 150 and 300 feet generally ccur in smaller bedrck valleys, in areas adjacent t bedrck valleys, and alng the length f the Mareng Mraine. Remaining areas generally have between 100 and 150 feet f drift, with substantial areas f drift less than 100 feet thick, particularly in the suthern part f the study area. There is n drift cver in small areas alng the Fx River and in nrthern De Kalb Cunty. Classificatin, Distributin, and Descriptin f the Drift. The assignment f varius drift materials t specific frmatins and members r stages (and substages) is based n the recgnitin f the characteristics, sequence, and cntinuity f depsits (particularly f 28 ILLINOIS STATE GEOLOGICAL SURVEY EGN 111

35 glacial tills) and their stratigraphic psitin relative t buried sils r ther nnglacial depsits (fig. 8b). Several tills with identifiable characteristics have been recgnized thrughut the study area. Tills, utwash, and ther related depsits differ frm bedrck units nt nly in their physical characteristics and mde f depsitin but als in their lcal thinning, thickening, and incrpratin f underlying materials. The ldest glacial depsits recgnized in the study area (fig. 8b) are prducts f several glaciatins during pre-l llinian, lllinian, and pssibly earliest Wiscnsinan time (500,000 t 28,000 years ag). Older pre-lllinian depsits (Banner Frmatin) have been tentatively identified in De Kalb Cunty (Kemptn, 1963). Depsits assigned t the Glasfrd and/r Winnebag Frmatins frm the bulk f the surface depsits arund the westernmst and nrthernmst prtins f the area (fig. 3). Thrughut the remainder f the regin these lder depsits are largely buried by Wiscnsinan-age drift f the Wedrn Frmatin (Wdfrd ian Substage). The classificatin f the drift in the study area is changing cnsiderably in light f cntinuing studies within the regin, particularly fr the Winnebag and Glasfrd Frmatins. Tills and assciated depsits frmerly thught equivalent t thse f the Winnebag Frmatin in Bne r Winnebag Cunties t the nrthwest (Berg et al., 1984) are nw cnsidered separate units within the Glasfrd Frmatin and are f lllinian age. Wrk is currently underway t clarify these changes. Each till is distinct in its physical and mineralgical characteristics, and retains these unique characteristics n a reginally stratigraphic basis (Kemptn and Hackett, 1968a, 1968b). While a reginal framewrk fr these tills is beginning t emerge, additinal data and study are necessary t define the successin and thus aid in their predictability. Banner Frmatin. Depsits thught t be pre-lllinian, mainly sand and gravel, have been described frm well samples near the bttm f the drift filling the Try Bedrck Valley in suthern De Kalb Cunty (Kemptn, 1963). Hackett (1960) suggested that a thin basal sand in the Rck Bedrck Valley was als pre-lllinian. Recent studies (Berg et al., 1984) have assigned these basal sands and related depsits in the Rck Bedrck Valley in Winnebag Cunty t the Banner Frmatin. Hwever, their presence in the study area has nt been recently verified either in the Rck r Try Bedrck Valleys. Glasfrd Frmatin. The depsits assigned t the Glasfrd Frmatin lie directly abve the bedrck and belw the Wedrn Frmatin r Rbein Silt and als belw thse depsits crrelative with the Winnebag Frmatin in Bne and Winnebag Cunties. It appears likely that mst depsits, particularly the tills, are lllinian (fig. 8b) and shuld be assigned t the Glasfrd Frmatin; hwever, n frmal assignment has been made as yet. Figures 18a t 18e dcument the cmplexity, thickness, and extent f these depsits. While many hundreds f water well lgs, available fr the entire regin, suggest their general lithic characteristics, rughly 30 t 40 test hles have als been sampled, lgged, and described, gelgically defining the entire successin. The appendix cntains examples f these lgs. Althugh till appears t be the dminant material within the Glasfrd Frmatin, utwash sand and gravel as well as lcal depsits f lacustrine sand, silt, and clay ccur frequently between tills. The thickest till sequences tend t lie abve the bedrck uplands, while the thickest sand and gravel depsits tend t ccur as fill in the buried bedrck valleys r in channels cut int the tills. Winnebag Frmatin. The Winnebag Frmatin was named fr tills and assciated depsits that ccur t the nrthwest f the study area in Winnebag and Bne Cunties (Frye et al., 1969); the frmatin nw appears t be restricted primarily t that area (Berg et al., 1984; Kemptn et al., in preparatin). Therefre, mst depsits previusly assigned t the Winnebag Frmatin in the study area (Kemptn and Hackett, 1968a, 1968b; Kemptn and Grss, 1971) are nw thught t be lder. Sme utwash sand and gravel depsited directly belw the Rbein Silt r Wedrn Frmatin materials may be related t SSC: PRELIMINARY GEOLOGICAL FEASIBILITY REPORT 29

36 N T42N T4 1 T40N T39N T38N T37N Figure 18a. Lcatin f drift crss sectins. utwash and tills f the Winnebag Frmatin. Until clearcut relatinships can be established, hwever, nne f these depsits has been frmally assigned t the Winnebag. Rbein Silt. One significant marker hrizn within the drift is the Rbein Silt, a relatively thin, discntinuus successin f rganic sediments and related depsits lying between the Glasfrd Frmatin r Winnebag Frmatin and the Wedrn Frmatin (fig. 8b). It has been reprted in numerus water well lgs as "peat," "muck," "driftwd," and has been sampled during test drilling f several water-resurce test hles. It may be a surce f the methane gas that may be encuntered in the drift (Meents, 1960; Cleman, 1976). While its lcal ccurrence is nt predictable, it is mst frequently reprted in a nrth-suth band 10 t 15 miles wide in central Kane Cunty (figs. 18a, b, and d). Wedrn Frmatin. The Wedrn Frmatin (figs. 8b, and 18a-d) cnsists f a successin f tills, generally cntaining minr amunts f interbedded utwash sand and gravel and lacustrine silt and clay. Individual tills have been identified and mapped thrughut the regin. Three principal tills have been named: in ascending rder they are the Tiskilwa, the Maiden, and the Yrkville Till Members. 30 ILLINOIS STATE GEOLOGICAL SURVEY EGN 111

37 00 DC 8 y cc t- in 3 < «0«; ; ;r!;etn S m g =3hO 5 O Si *> I- O a 0«"i-S &5 i- 3 CO 6 t ^ ^ I cc lee uj UJ m Ct LU «* I (E 3A3 eas ueauu 3Aqe uijeaa ^ 1 CO CO CO J2 UJ 00 c l.2> u- Z SSC: PRELIMINARY GEOLOGICAL FEASIBILITY REPORT 31

38 Hi CO cr UJ tr UJ Cl > I- z D «*g 8 CO -I < it UJ Q UJ in cr UJ c UJ DC t m CD -r CT) s -T O If) 0) m t O k. u u CO UJ 1 w IS i. 3 cn c 0> U. (J 9A3 eas ueaiu aaqe uijeaaig 32 ILLINOIS STATE GEOLOGICAL SURVEY EGN 111

39 1 i CD a. < Q uj *CC l-m l K O OQ _l < a> D s O 6 UJ in tr UJ <* DC T I O O 1 I I O O 1 1 I 8 in in in m in m m en CD CO CO t^ r- CO CD in in «t 5 n C"J 1 3A3 eas ueaw aaqe ujjeaaig c/> SSC: PRELIMINARY GEOLOGICAL FEASIBILITY REPORT 33

40 IEEE E i i r- f in 00 -f t -I s IT) T O m CO.2> U. z 3A9 eas ueauj aaqe uueaaig 34 ILLINOIS STATE GEOLOGICAL SURVEY EGN 111

41 R2E T42N T41N T40N T39N T38N T37N \///\ Tiskilwa Till Mbr absent <s' Elevatin abve mean sea level Cntur interval 50 feet mi Figure 19. Elevatin, base f Tiskilwa Tiil Member (frm Wickham, 1979). Tiskilwa Till Member. This till is the thickest, mst intensively studied drift unit f the area. The mst recent study by Wickham (1979) is the basis fr the fllwing descriptin and fr figures 16, 19, 20, and 21. The glacier that depsited the Tiskilwa Till abut 23,000 years ag advanced int the area (Kemptn and Grss, 1971 ) ver tills and utwash f the Glasfrd and Winnebag Frmatins and lcal depsits f the Rbein Silt. The elevatin f this ancient land surface is shwn n figure 19. The Tiskilwa is a remarkably hmgeneus, calcareus, lam t clay lam till; it has an unxidized clr f brwn t grayish brwn with a pink cast and is typically described as pink r red sandy till r clay in well lgs. Althugh it is generally unifrm with a weak blcky structure, it may cntain thin, discntinuus layers f gravel, sand, and silt. The till matrix has an average cmpsitin f 35 percent sand, 39 percent silt, and 26 percent clay (table 1 ). The till cntains less sand but mre clay in the western part f the area. Fine t carse gravel and cbbles are cmmn; sme bulders are present. The upper part f the Tiskilwa ften cntains variably textured till interbedded with thin layers f srted gravel, sand, silt, and clay (ablatin till). Sme srting has taken place, and ablatin depsjts are frequently carser and less massive than the usual Tiskilwa Till; hwever, they are nt easily distinguishable frm the underlying till. A basal zne, nted als in the Tiskilwa, is finer grained. SSC: PRELIMINARY GEOLOGICAL FEASIBILITY REPORT 35

42 Table 1. Prperties f gelgic units in nrtheastern Illinis (mdified frm Kemptn, Bgner, and Cartwright, 1977, except where nted). The infrmatin in this table accmpanies the text n engineering prperties. Unit N qu W dd gr sd St cl Cahkia Alluvium X n R Grayslake Peat X n R Richland Less X n R Equality Frmatin Carmi Member X n R Equality Frmatin Dltn Member X n R Henry Frmatin Mackinaw & Batavia Members X n R (1.5) (4) ( ) (17) (19) (11-23) Yrkville ablatin X n R Yrkville Till Member X n R Yrkville cmpsite X n R Yrkville Till* Member X s n Yrkville ** (Unit B, n. 1) X n Yrkville** (Unit B, n. 2) X n ND Maiden Till Member X n R Maiden Till Member* X s n Maiden (Unit C, n. 3)** X n ND Maiden (Unit C, n. 4)** X n Maiden (Unit C, n. 5)** X n Maiden &? (Unit D, n. 6)** X n ND Maiden Outwash X n R Tiskilwa ablatin X n R Tiskilwa Till Member X n R ILLINOIS STATE GEOLOGICAL SURVEY EGN 111

43 Table 1. Cntinued Unit qu W dd gr sd St cl Tiskilwa Till Member Tiskilwa (Unit E, n. 7) ND Rbein Silt Glasfrd Frmatin Banner Frmatin x mean n number f tests r samples R range f data; lw-high s standard deviatin N number f blws per ft (Standard Penetratin Test) qu uncnf ined cmpressive strength in tns per square ft W natural misture cntent in percent dd dry density in punds per cubic ft gr percent f gravel in ttal sample sd sand, 2 t 0.62 mm st silt, 0.62 t.0039 mm cl clay, <.0039 mm ND n data * frm Wickham, 1979 ** frm Landn and Kemptn, 1971 The Tiskilwa Till is present thrugh much f the study area (fig. 20). Its greatest thickness in the study area ccurs beneath the Mareng Mraine (fig. 7) in the nrth-central part f Kane Cunty, where it exceeds 200 feet. Thicknesses f 100 t 150 feet ver large areas are cmmn in the east, nrth, and central parts f De Kalb Cunty and in nrthern Kane Cunty. With sme exceptins, a nrtheast-suthwest trending line drawn thrugh the center f the study area separates areas f thinner Tiskilwa (less than 50 feet) in the sutheast frm thicker till in the nrthwest (fig. 20). A majr exceptin is the Mareng Mraine, a ridge extending suth int central Kane Cunty. The Tiskilwa is absent lcally in the nrth, primarily in river valleys where ersin has ccurred. Till alng the Kishwaukee River valley has been thinned r remved, cutting the nrthern half f the Tiskilwa depsit int tw segments. The till appears t be absent in tw large areas near the center f the study area and in ther areas near the irregular suthern bundary f the till. The thinning and absence f Tiskilwa Till beneath areas f yunger glacial depsits in the suth is attributable t bth fluvial and glacial ersin. Meltwaters flwing alng the Fx River have substantially erded the till present in the valley in bth Kane Cunty and nrthern Kendall Cunty. In suthern Kane Cunty, ersin by yunger glaciers is a prbable cause fr the thinning f the Tiskilwa Till. The Tiskilwa extends t near the eastern edge f Kane Cunty; its eastern bundary may nt extend much mre than 1 r 2 miles east f the Fx River. Thin wedges f the till extend int nrthern Kendall and suthern De Kalb Cunties. In the west the Tiskilwa thins abruptly as its western bundary extends nrth thrugh eastern Lee and Ogle Cunties and east thrugh nrthern De Kalb Cunty. The Tiskilwa is present thrughut nrtheast Kane Cunty and extends nrth int McHenry Cunty. The tpgraphy f the Tiskilwa Till surface is parallel t land surface ver much f the area, except where cvered by Equality Frmatin lacustrine sediments and Henry Frmatin glacial utwash sand, r in the suth and sutheast where the Tiskilwa is cvered by relatively thin Maiden r Yrkville Tills. Its surface elevatin is at a maximum alng the end mraines t the nrth and west, and decreases tward the sutheast. The tpgraphy f the sub-tiskilwa surface is smewhat mre cmplex (fig. 19) and generally drps tward the sutheast: the sutheastern half f the area is smewhat irregular, and the nrthwestern half is an irregular surface at an average elevatin f 750 t 800 feet, bisected by a nrtheast-suthwest trending buried ridge f up t 850 feet elevatin. SSC: PRELIMINARY GEOLOGICAL FEASIBILITY REPORT 37

44 i R9E T42P i t 1 r 1 **.^ Xs m*w0& 4% : $i!&<$&&$&. \C^\ Tiskilwa Till Mbr absent [yly/sj Tiskilwa Till Mbr utcrps r50' Thickness f Tiskilwa Till Mbr in feet Cntur interval 50 feet mi Figure 20. Thickness f Tiskilwa Till Member (frm Wickham, 1979). Maiden Till Member. The Maiden Till verlies the Tiskilwa Till in the suthern half f Kane Cunty and apprximately the suthern third f De Kalb Cunty (fig. 21). In cmparisn t the Tiskilwa, it is relatively thin, prbably averaging little mre than 30 feet thick. It is a yellwish brwn, tan, r gray, predminantly sandy t silty till averaging 36 percent sand, 43 percent silt, and 21 percent clay (table 1 ). Lcally it is quite gravelly and /r cntains inclusins f sand and gravel and pink Tiskilwa Till incrprated frm belw. Inclusins f underlying till may have mixed thrughly enugh t create a mixed till f highly variable cmpsitin and texture. Extensive areas are cvered by this "mixed cmpsitin" till (fig. 21 ), and it may cmpletely replace the Tiskilwa in sme areas. The end mraine that marks its margin in west-central Kane Cunty and in east-central and suth-central De Kalb Cunty is very hilly r knbby, many f the hills being cmpsed partially f sand and gravel with till inclusins. In the sutheastern prtins f the study area the Maiden Till is thin r absent, prbably the result f ersin by late glacial meltwater flds alng the Fx River. Thrughut the suthernmst prtins, the Maiden and the underlying Tiskilwa Till are quite thin (fig. 18c-d). Als in this area a lcally significant utwash sand and gravel directly underlies the Maiden. This utwash is the surficial material in sme areas f nrthwestern Kendall Cunty where the Maiden Till has been erded. 38 ILLINOIS STATE GEOLOGICAL SURVEY EGN 111

45 1 h ) T42N T39f\ T38r- Henry Fm Equality Fm -] Henry-Equality cmplex -discntinuus WEDRON FORMATION wy Figure 21. Yrkville Till Mbr ice cntact-lacustrine cmplex; sme mixed cmpsitin Surficial gelgy (frm Wickham, 1979). wm Maiden Till Mbr I [ II till -mixed cmpsitin \>\:' :\] ice-cntact-mixed cmpsitin Tiskilwa Till Mbr GLASFORD FORMATION I gt IGlasfrd Tills Yrkville Till Member. The Yrkville Till verlies the Maiden Till near the eastern edge f the study area (figs. 21 and 18b) and directly verlies the Tiskilwa Till in the nrtheast (fig. 18a). It is a very clayey, silty, gray till (generally mre than 40% clay; table 1 with little sand (less than 15%). Clr varies frm brwn r grayish brwn in the upper xidized prtin t dark gray at depth. Numerus dlmite pebbles are characteristically present. The Yrkville may be mre than 50 feet thick, but generally appears t be 20 t 30 feet thick where it is present in the study area. The Fermilab Tevatrn has been placed in this till. The Yrkville depsits mapped (fig. 21) are actually a cmplex series; cmpsitin varies due t differences in frmatin and depsitin. The cmpsitin f the basal Yrkville depsits is cnsistent with the general descriptin prvided abve; hwever, the upper depsits have typically been mdified t sme extent by water and mass wasting prcesses SSC: PRELIMINARY GEOLOGICAL FEASIBILITY REPORT 39

46 t frm ablatin till. These depsits are usually mre sandy and may be less cmpact than basal till. Ablatin till, nt mapped separately, is included in the "nrmal" Yrkville depsits n figure 21. Landn and Kemptn (1971) have nted these tw phases at the existing Fermilab. A mre detailed study f this till is reprted by Kemmis (1981 ). Extensive lacustrine (lake) depsits are assciated with the Yrkville Till west f Elgin. When these silt and clay depsits are intermixed with stratified silt, clay, sand and gravel, they are referred t as ice-cntact drift. Ice-cntact drift is cmpsed f materials depsited in r n ice; when the ice melts, these remain as characteristic features n the land surface. Sme mixed-cmpsitin till, resulting frm the incrpratin f basal tills (Maiden and Tiskilwa) during Yrkville Till depsitin, is als present. The Yrkville mixed-cmpsitin till is identical t Maiden mixed-cmpsitin till and is differentiated by stratigraphic psitin. All three types (lacustrine depsits, ice-cntact drift, and mixed-cmpsitin drift) are mapped as part f the Yrkville lacustrine/ice-cntact cmplex (fig. 21 ). Thick utwash depsits may be present beneath the Yrkville Till in the sutheast, and have been mapped as wy- n the crss sectins (fig. 18c). They may be expsed in sme areas where the Yrkville Till has been erded. Henry Frmatin. The Henry Frmatin cnsists f discntinuus glacial utwash depsits cmpsed predminantly f sand and gravel (table 1). It is a surficial r near surficial depsit, generally verlain nly by less (windblwn silt), Cahkia and Equality Frmatins, and mdern sils. The Henry Frmatin may vary frm thin, well srted sheet-like depsits t hills f prly srted silt, sand, and gravel. The hills are ice-cntact depsits frmed within r under the glacier and are generally quite discntinuus and limited in area. They are nt mapped separately in this reprt. Several f these features are fairly prminent landfrms lcated west f the Fx River in central Kane Cunty. Thin sheets f Henry Frmatin present in the study area are believed t be glacial utwash plain and valley train depsits and may be relatively cntinuus and widespread. Distributin is generally limited t narrw bands alng present river valleys (frmer glacial drainageways) thrughut the study area. Extensive depsits f Henry are present near the eastern and suthern edges f the study area n either side f the Fx River (fig. 21 ) as well as near the nrthern and nrtheastern edges alng the Kishwaukee River valley. Because Equality and Henry Frmatin depsits were ften frmed simultaneusly r alternately, they are usually intermixed and difficult t differentiate, s they are mapped as the Henry-Equality cmplex (fig. 21 ). Extensive areas cvered by these generally thin depsits (less than 20 ft thick) are present in the sutheast (west f the Fx River) and in the nrthern part f the study area near the Kane-De Kalb bundary. Equality Frmatin. Areas mapped as Equality Frmatin were frmerly cvered by extensive lakes frmed during and just fllwing the final retreat f glaciers. The depsits cnsist mainly f silts and clays (table 1 ), with sand generally as a minr cnstituent. Lacustrine depsits dating frm earlier times are nt cnsidered Equality Frmatin but are instead mapped as part f the frmatin in which they ccur (Wedrn r Glasfrd). The Equality Frmatin is discntinuusly present thrughut the study area (fig. 21) and may be mixed with Henry Frmatin depsits. Large areas cvered by lacustrine depsits are present suthwest f De Kalb (alng the suth branch f the Kishwaukee River), in the nrtheast (west f Elgin), and in the suthwest and sutheast crners f the study area. The Equality is generally thin (less than 20 ft) and ften verlies sand and gravel f the Henry Frmatin (fig. 18a). Cahkia Alluvium. The Cahkia Alluvium is the prper frmatin name fr recent depsits in the fld plains and channels f mdern rivers. The frmatin is generally cmpsed f silt with discntinuus sand and gravel lenses. The sediments are generally depsited during fld intervals, and in the study area, they are prbably rather thin (10 t 20 ft r less). This frmatin is nt mapped n figure 21 but is shwn n several crss sectins (figs. 18a, b, and c). It ften verlies Henry and Equality depsits (fig. 18a). Althugh fund thrughut the study area, it is limited t the immediate vicinity f area rivers and streams. 40 ILLINOIS STATE GEOLOGICAL SURVEY EGN 111

47 Very ENGINEERING PROPERTIES OF GEOLOGIC UNITS The engineering prperties discussed in this sectin are based n data gathered and summarized frm previus studies. These include the reprt n the stratigraphy f the current Fermilab site (Landn and Kemptn, 1971 ) a reprt n reginal gelgy fr planning in nrtheastern Illinis (Kemptn et al., 1977), a master's thesis based n data gathered frm drilling fr the present Fermilab ring (Kemmis, 1978), and a master's thesis invlving a cmprehensive reginal study f the Tiskilwa Till (Wickham, 1979). The engineering prperties listed in table 1 are N fr number f blws per ft (Standard Penetratin Test), Qu fr uncnfined cmpressive strength in tns per square ft, W fr natural misture cntent, expressed as a weight percent, and dd fr dry density in punds per cubic ft. Standard Penetratin Test, determined during drilling, is the number f blws (N) required t drive a sampler 12 inches int a sil material by drpping a 140- pund hammer a distance f 30 inches; it is an empirical test cmmnly used t indicate relative in situ bearing strengths f materials. Table 2 indicates grupings f apprximate bearing strengths f clayey and sandy sils. Uncnfined cmpressive strength in tns per square ft (Qu) is an additinal measure f bearing strength. Mst data under this heading were btained by standard field methds. Table 2 includes uncnfined cmpressive strength categries fr clayey and sandy sils. Natural misture cntent (W) is expressed as a percentage f the weight f water in the sample relative t the ven-dry weight f the sample. Table 3 categrizes materials by natural misture cntent. Dry density (dd) determinatins are given in punds per cubic ft. Table 4 categrizes rck and sil. Sil referred t by the getechnical engineer is equivalent t glacial drift. Table 2. Grupings f apprximate bearing strengths (after Terzaghi and Peck, 1967; frm Bergstrm, Piskin, and Fllmer, 1976). Clayey si s Sandy sils Relative strength Field test Uncnfined cmpressive strength (tns/ft 2 ) Standard penetratin test, blw cunt* Standard penetratin test, blw cunt* Relative density Lw sft Easily penetrated several inches by fist Sft Medium Easily penetrated several inches by thumb Can be penetrated several inches by thumb with mderate effrt Very lse Lse Medium Stiff Very stiff Readily indented by thumb, but penetrated nly with great effrt Readily indented by thumbnail Medium Dense High Hard Indented with difficulty by thumbnail >4.0 >30 >50 Very dense 'Blw cunt fr 12-inch penetratin (140-lb hammer; drp f 30 in.). SSC: PRELIMINARY GEOLOGICAL FEASIBILITY REPORT 41

48 Table 3. Natural misture cntent (Bergstrm, Piskin, and Fllmer, 1976). Misture cntent (% dry wt) Materials Very high) High J > Organic materials, including peat Medium Materials rich in rganic matter r alluvial silts and clays Lw Less, carse alluvium, clluvium, r weathered till Very lw <10 Unweathered till, desiccated materials, r bedrck Table 4. Dry density weight (Bergstrm, Piskin, and Fllmer, 1976). Sil Rck lb/ft 3 g/cc lb/ft 3 g/cc Very high >145 >2.3 High >170 >2.7 Medium Lw Very lw <90 <1.4 <120 <1.9 Table 1 als lists average percentages f gravel in the ttal sample; f sand, silt, and clay in the sample matrix; and f the clay mineral cmpsitin f the!ess-than-2-micrmeter fractin. Physical Characteristics f the Drift The tills and sand and gravel depsits in this regin range frm medium t high in bearing strength. The wide range f blw cunts in the sand and gravel units prbably indicate the variability f these materials. Less, fine-grained lake sediments, and alluvium als exhibit variable strength characteristics. Landscape psitin and misture cntent accunt fr wide variatins in sme units. Alluvium and lake sediments, where lwest n the landscape, are mst likely t exhibit high misture cntent, depending n the seasn f the year and the amunt f recent precipitatin. Less, which generally mantles the uplands, exhibits lw bearing strength when saturated; when dry and well drained, it is capable f medium t high bearing strengths. It is als highly susceptible t piping (subsurface ersin) when wet. Carse-grained, well srted (prly graded) sediments such as sands and gravels tend t have higher misture cntent than prly srted (well graded) depsits because f their higher prsity and permeability. Depsits that are prly srted cntain significant amunts f fine-grained sediments, tend t exhibit a lw prsity and permeability, and therefre, have a lwer misture cntent. Cnsequently, well srted sands and gravels exhibit gd drainage; whereas prly srted sediments such as till and very fine-grained less, lacustrine silts, and clays d nt. Less and sme alluvial depsits average high in expandable clay minerals. As mentined earlier, gelgic materials that cntain an appreciable percentage f expandable clay min- 42 ILLINOIS STATE GEOLOGICAL SURVEY EGN 111

49 erals have a high shrink-swell ptential. Fine-grained alluvial silts and sands situated in prly drained psitins n the landscape have a high ptential fr frst heave. Nne f the gelgic units listed shuld cause excavatin csts t be higher than nrmal. Sme may frm unstable slpes in excavatins, particularly saturated less, alluvium, lake sediments, and uncnfined sand lenses. In general, glacial till is a gd fill material fr cnstructin purpses. One ptential prblem is that till units may include cbbles and bulders f different sizes, causing difficulties in drilling, excavatin, r tunneling. "Bulder pavements" may als ccur between glacial depsits r at the base f large buried stream valleys. Physical Characteristics f the Bedrck Sme physical characteristics f the bedrck are described in table 5, which presents sme additinal detail n the varius grups, frmatins, and members described in the stratigraphic sectin f this reprt (fig. 8a). Available physical strength data fr the varius rck units are presented as a range f values. These values shuld be used with cautin since they represent results frm a limited number f samples at varius depths, frm different lcatins. T paraphrase an imprtant principle stated in the 1982 Annual Bk f Standards f the American Sciety fr Testing and Materials, strength prperties f Table 5. Physical prperties f bedrck units.* Uncnfined Indirect cmpressive tensile Tangent Number strength strength mdulus f (psi) (psi) (psi x 10 6 ) samples Cambrian System Mt. Simn Sandstne Eau Claire Frmatin Galesville Sandstne Irntn Sandstne Francnia Frmatin Ptsi Dlmite Eminence Frmatin Ordvician System Prairie du Chien Grup Shakpee Dlmite Ancell Grup Platteville Grup Galena Grup Maquketa Grup Frt Atkinsn Dlmite Sandstne, carse grained, friable; may cntain quartz pebbles up t abut 4 mm acrss. Sandstne, dlmitic; siltstne, shaley; and dlmite, silty, sandy, glaucnitic. Sandstne, fine grained, mderately well srted, friable; generally nndlmitic but lcal dlmite cement may be fund. Sandstne, carse grained, prly srted; generally cntains dlmite as cement and dlmite pebbles in cnglmeratic layers. Sandstne, fine grained, glaucnitic, silty, argillaceus, dlmitic. Dlmite, finely crystalline, pure t slightly argillaceus. Dlmite, fine t medium grained, sandy; cntains litic chert and thin beds f sandstne. Dlmite, cherty; sme interbedded sandstne. Sandstne, friable r weakly cemented; limestne and dlmite, argillaceus, sandy. Dlmite, fine grained, cherty. Dlmite, medium grained, cherty. Shale, dlmitic, silty; lcally cntains interbeds f fine- t medium-grained dlmite and/r limestne. 8,200-11, , ,000-36,000 1,300-2, Silurian System Dlmite, pure, cherty. 5,600-36, , 'Randm samples frm air-dried cres. Data frm ISGS Rck Mechanics data base. SSC: PRELIMINARY GEOLOGICAL FEASIBILITY REPORT 43

50 rck cres as measured in the labratry generally d nt accurately reflect prperties f large-scale rck masses in the field because the latter are ften influenced by jints, faults, inhmgeneities, weakness planes, and ther factrs. Labratry values btained frm intact specimens must therefre be used with prper judgment in engineering applicatins. Uncnfined cmpressive strength measurements are determined using standard lengtht-diameter ratis f 2. Samples must be tested befre the natural water cntent evaprates frm the cre. This test indicates the lad-bearing strength f the rck. Indirect tensile strength measurements are used t measure the maximum stress the sample can withstand withut pulling apart. Samples must be tested with natural misture cntents t achieve gd test results. Tangent mdulus is a standard methd t determine the relatinships f stress t strain in a rck. The strength values presented in table 5 are based n air-dried samples taken frm nrthern Illinis. Future getechnical studies must include field and labratry testing f Quaternary materials and bedrck as a basis fr better definitin f the engineering characteristics f these units and the cnditins that will be encuntered during excavatin, drilling, tunneling, and cnstructin phases f the prject. HYDROGEOLOGY Surce, Mvement, and Availability f Grundwater The relatinship f water t the gelgic materials within the regin must be understd t prvide a basis fr evaluating site suitability. In Illinis, the surce f grundwater is precipitatin bth rain and snw infiltrating lse particles f the sil and eventually perclating dwnward. Belw a certain depth, called the "tp f the zne f saturatin" r "water table," almst all penings (pres) in the earth materials are filled with water. (Abve the water table, pre spaces are filled with bth water and air.) This definitin f water table is independent f the character f earth materials; therefre, it is nt related t the availability f grundwater t wells. A tightly packed, fine-grained material may be cmpletely saturated with water, yet the yield and rate f recharge (mvement f water int a well) wuld nt be sufficient fr use. Grundwater is stred in the zne f saturatin in penings ranging in size frm tiny pres between particles f clay and silt, t small pres in sandstne, t larger pres between grains f sand and gravel, t large crevices r slutin channels in dlmite and limestne. The pre space f an earth material is its prsity, expressed as a percentage f ttal vlume f the material. The size and intercnnectin f the pres determine hw easily earth materials transmit water under a pressure gradient frm areas f high ptential energy t areas f lw ptential energy. This is referred t as the hydraulic cnductivity. Permeability refers t the capacity f an earth material t transmit any fluid; whereas hydraulic cnductivity refers t the interactin f bth material and water. Under natural cnditins, the water table rughly parallels the surface tpgraphy: it rises under the uplands and intersects the grund surface in the lwlands, frming perennial streams, lakes, swamps, and springs. Grundwater enters these surface-water bdies because f gravity flw frm adjacent areas where the water table is higher. Frm seasn t seasn and year t year, the psitin f the water tables and the discharge f grundwater t streams fluctuate. During wet perids, fr example, the water table is usually at r near the surface. The water table can be lcated in any material. Even after a well has been drilled belw the water table, grundwater is nly rapidly available frm material with sufficient hydraulic cnductivity. Thus, the presence f water des nt necessarily mean the presence f an aquifer. Any large excavatin belw the water table even in materials with lw hydraulic cnductivity will fill with water, thugh very slwly. 44 ILLINOIS STATE GEOLOGICAL SURVEY EGN 111

51 An aquifer is a natural earth material that yields sufficient water t a well t satisfy the need fr drilling it. Thus, an aquifer supplying adequate water fr a single residence might nt be an aquifer fr a municipality. Fr this reprt, the term aquifer refers t earth materials capable f supplying water t several residences. Aquifers may be uncnfined r cnfined. In an uncnfined aquifer, the water table is the tp f the water-yielding materials; n impermeable materials verlie the aquifer, cnfining it. In a cnfined aquifer, als knwn as an artesian aquifer, the grundwater is cnfined under pressure greater than atmspheric pressure by verlying, relatively impermeable materials. This pressure causes the water in a well t rise abve the tp f the aquifer. A well in which water rises t land surface is a flwing artesian well. In sme places, materials abve the main water table becme saturated, resulting in perched water tables: fr example, several feet f windblwn silt (less) may verlie a clay-rich glacial till. Because silt is mre prus than clay, water will generally mve mre easily thrugh the less than thrugh the clay and cllect just abve the clay, prducing a saturated zne r perched water table. Als, small, relatively thin sand and gravel layers between less and clay-rich till might frm perched aquifers, althugh they rarely yield enugh water t supply even a small husehld. Water Resurce Distributin Tw principal types f materials yield grundwater in Illinis: (1 ) sand and gravel depsits within glacial drift and alng river valleys; and (2) sandstne, limestne, and dlmite frmatins within bedrck. Table 6 summarizes the water-yielding ptential f the gelgic units in the study area. Table 6. Gelgic units as ptential aquifers Gelgic unit Water-yielding characteristics Glacial drift Yields highly variable; largest supplies frm thick, extensive sand-andgravel beds within Glasfrd and Henry Frmatins. Silurian Lcal availability frm fractures mainly in eastern mst prtin f area; small t mderate supplies. Maquketa Small supplies lcally frm fractured dlmite and /r shale; generally nt water-yielding. Galena-Platteville Small t mderate supplies where fractured and nt verlain by Maquketa. Ancell (Glenwd-St. Peter) Mderate supplies. Prairie du Chien Small t mderate supplies; lcally large in suthern part f area. Eminence-Ptsi May yield small supplies where fractured. Francnia Generally nt water yielding; small supplies lcally. Irntn-Galesville Highly prductive aquifer in central and western parts f area; large supplies; extensively used in eastern prtin f area. Eau Claire Generally nt water yielding. Lwer sandstne included with Mt. Simn. Mt. Simn Mderate t large quantities f water; water quality gd at tp but deterirates with depth. Precambrian granite Nt water yielding. SSC: PRELIMINARY GEOLOGICAL FEASIBILITY REPORT 45

52 . Apprximate utline f Try Valley Sand and gravel >10 ft thick at a depth f 0-50 ft _ Apprximate utline f small buried valley-areas f ]] Sand and gravel >10 ft thick at a depth f ft pssible sand and gravel Figure 22. Ptential surficial and buried sand-and-gravel aquifers. r^^ Sand and gravel > 10 ft thick at a depth > 100 ft Drift aquifers include several basic types each exhibiting a different water-yielding capacity and suitability fr use by husehlds, municipalities, industries, and thers. Fr example, drift ften cntains relatively thin, discntinuus depsits f sand and gravel. Due t their lw yields, these water-bearing depsits are nly suitable fr small, dmestic supplies. Althugh they may be encuntered at any depth within the drift, the mst cmmn lcatin is just abve r resting n the bedrck. In much f the study area, particularly in De Kalb Cunty, these depsits are frequently passed because f the excellent grundwater ptential f deeper bedrck aquifers. The suth, east, and sutheastern parts f the study area have fairly widespread, thick, depsits f water-bearing sand and gravel, which are cmmnly used fr dmestic water supplies (fig. surces. 22). At present, mst wells in this area use a bedrck aquifer instead f drift In the future, the easy accessibility f these shallw aquifers may cnsiderably increase their use. Small t mderate water supplies are generally available frm these depsits. 46 ILLINOIS STATE GEOLOGICAL SURVEY EGN 111

53 The Try Bedrck Valley cntains thick depsits f sand and gravel (fig. 18b), generally belw an elevatin f 600 feet; thicknesses f mre than 100 feet have been reprted. Well data indicate, hwever, that the depsits may be much thinner r even absent in sme areas, particularly abve an elevatin f 600 feet. Pssibly because f this as well as the fact that the underlying bedrck (Galena-Platteville dlmite west f the Maquketa bundary, and St. Peter Sandstne) has excellent grundwater ptential, high-capacity wells develp mst r all f their yield frm the deeper bedrck. Hwever, sme dmestic and ther lw-yield wells may nt penetrate the entire drift thickness in the buried valleys because adequate dmestic supplies can be btained frm small depsits at much shallwer depths. The prspect fr develping grundwater supplies frm the bedrck are gd ver the entire study area. Silurian dlmite, which is generally fractured and creviced, is cmmnly used as an aquifer east f the Fx River. West f the Fx River, the thin scattered patches f Silurian rcks are generally unsuitable fr aquifer develpment. Much f the bedrck directly belw the drift west f the Fx River, extending acrss Kane Cunty int nrtheast De Kalb Cunty, is the Maquketa Shale Grup. The dlmite within the Maquketa is ccasinally utilized by dmestic r farm wells in Kane Cunty. Mderate supplies fr subdivisins may als be available in a few lcatins. Because the shale facies f the Maquketa generally has lw permeability, it des nt yield water except where it is fractured. Lcally, fractures may permit the cnstructin f lw-yield wells. The Galena-Platteville dlmite underlies the entire study area nrth f the Sandwich Fault, except in part f the Try Bedrck Valley. The Galena-Platteville is generally a reliable surce f grundwater where it lies directly belw the drift; it may yield mderately large supplies where fractures are encuntered in the upper 75 feet. A large number f dmestic, industrial, and municipal wells develp supplies frm the Galena-Platteville in De Kalb Cunty. It is cmmn t drill thrugh water-bearing sands int the bedrck, partly because the dlmite has a ptentially higher yield, and partly because it is easier t cnstruct wells in this type f bedrck. East f the bundary f the Maquketa Grup, relatively few wells btain water frm the Galena-Platteville where it lies belw the Maquketa. The St. Peter Sandstne and the lwer Ordvician/upper Cambrian dlmite and sandstne may yield mderate t large quantities f grundwater. These rcks immediately underlie the drift just suth f the Sandwich Fault and are a cmmn surce f grundwater in that area. Nrth f the fault they are generally used fr municipal r industrial supplies. POTENTIAL GEOLOGIC CONSTRAINTS Seismicity The seismic risk map fr the cnterminus United States, develped by Algermissen (1969), shws that this area can expect nly minr damage frm future seismic activity. Prbabilistic hrizntal acceleratin caused by earthquakes in nrthern Illinis (Algermissen et al., 1982) is nt expected t exceed 4 (as a percentage f gravity) in 50 years r 9 in 250 years (fig. 23). Because histric data are scarce, accurate predictins are extremely difficult. Since 1804, nly seven histrical earthquakes have been epicentered in nrthern Illinis (Heigld, 1972). Nne f these quakes has had a maximum intensity abve VI n the mdified Mercalli Intensity Scale, which ranges frm I t XII. (An intensity f VIII n this scale crrespnds t the lwer limit f serius damage t manmade structures [Heigld, 1972] ). As mentined earlier in the discussin f bedrck gelgy, n displacement alng the Sandwich Fault Zne has ccurred in histrical times nr has any mvement been recgnized in mapping Quaternary units that may be as ld as 400 thusand years in this regin. Althugh the seismic risk fr any part f the state is lw, a repeat f the events that ccurred in the New Madrid Seismic zne (fig. 23) during the winter f culd have sme effect n Illinis. T assess the ptential risk fr different areas f the Midwest, SSC PRELIMINARY GEOLOGICAL FEASIBILITY REPORT 47

54 300 mi 3 ISGS 1985 Figure 23. Preliminary map f hrizntal acceleratin (expressed as percent f gravity) in rck with 90 percent prbability f nt being exceeded in 50 years (mdified frm Algermissen et al., 1982). 48 ILLINOIS STATE GEOLOGICAL SURVEY EGN 111

55 Ott W. Nuttli (1978) cnstructed an intensity map fr ne f the largest earthquakes f the sequence (December 16, 1811). An evaluatin f the effects n nrthern Illinis rated a seismic intensity n greater than VII n the mdified Mercalli Intensity Scale. Detailed data are available fr histrical earthquakes in and near Illinis 1972). (Heigld, Nuttli and Herrmann (1978) have frmulated an empirical equatin fr particle acceleratin and velcity, and this may be relevant t a cnsideratin f seismic risk in the vicinity f the ring. The recmmended relatin fr maximum hrizntal acceleratin fr the central United States is lg, a H (cm/sec 2 ) = m b lg 10 R R <15km m b lg 10 R R >15 km with a standard errr f estimate crrespnding t a factr f abut 2.0. The relatin fr maximum velcity is given as ' 9i v max (cm/sec) = m b 1.0 lg 10 R Finally, sils in the regin f the Fermilab site d nt generally have characteristics that wuld make them susceptible t liquefactin frm an earthquake. Subsidence The land surface may subside due t natural causes such as cllapse f natural caverns in karst regins. Man-induced subsidence may result frm cllapse f subterranean penings prduced by sme mining peratins r by withdrawing water t quickly frm lse sediments. The regin des nt have karst-type bedrck that wuld be expressed n the surface as sinkhle terrain. The upper surface f buried frmatins may exhibit sme f these features, but usually the penings are filled by depsits. There are n undergrund mining peratins in the regin that culd pssibly fail and cause subsidence. Glacial activity preladed the surficial materials in such a manner that all units except fr recent streambed alluvium have been precnslidated t a dense state. N case f subsidence has ever been reprted frm dewatering f these sediments. Slumping A ring f the size being discussed wuld crss and pass beneath Smnauk Creek, Big Rck Creek, Little Rck Creek, and the Suth Branch f the Kishwaukee River. Stream banks and adjacent fldplain areas may present sme unstable cnditins, which culd affect surface cnstructin activities and facilities unless prper cnstructin techniques are emplyed. EVALUATION OF THE GEOLOGY Grundwater as a Getechnical Prblem Identifying and mapping the distributin f materials that may cause prblems when saturated r under hydrstatic pressure is particularly useful infrmatin fr tunneling, shallw fundatins, and excavatins where slpe stability may be a prblem. Since a high water table and/r perched water are bth likely t ccur in the surficial materials f the study area, cut-and-f ill peratins must be designed t take these cnditins int accunt. Surface drainage is influenced by tpgraphy, by infiltratin rates related t the characteristics f surficial materials, and by the psitin f the water table. In thse parts f SSC: PRELIMINARY GEOLOGICAL FEASIBILITY REPORT 49

56 the study area with gentle slpes underlain by glacial tills r ther fine-textured materials, the tp f the zne f saturatin rughly parallels the land surface; it is likely t be at rather shallw depths and will lcally intersect the land surface in depressins and alng streams. In areas f carser depsits such as sand and gravel, surface drainage is usually gd due t relatively rapid infiltratin and a generally lwer water table. Cnstructin prblems. High water-table and perched-aquifer cnditins (see Hydrgelgy, p. 44) can ccasinally cause prblems in belw-surface, and particularly, nearsurface cnstructin prjects. Sft fundatins and unstable cuts in excavatins are cmmn during wet perids. In sme places drainage must be engineered under the mst severe cnditins. Unstable slpes may result frm expsure f materials that flw easily (such as sand) when supprt is remved. A high water table als prduces unstable cnditins: interstitial water may reduce strength in fine-grained materials, such as silt, which cllapse if the sides f the excavatin are cut t steeply. In additin, a large excavatin that extends belw the water table must be engineered t maintain dry cnditins in the planned wrking space. The sils r rcks seep water int undergrund penings at a rate dependent upn their hydraulic cnductivity. Gelgical Features Sme features f the site will cnstructin technique used. Mst prminent is the Sandwich Fault Zne lcated at the suthern end f the site. influence design and rientatin f the ring regardless f the This fault has been inactive fr millins f years; hwever, it represents a significant gelgic feature due t the rapid variatins f materials acrss the zne as well as the crevices and breaks caused by the fault. Cnsequently, the faulted area is nt well suited t undergrund tunneling techniques. Natural waterways will als affect ring rientatin (fig. 2a). The Fx River is especially significant because it bttms n bedrck in the regin west f Fermilab. If any part f the SSC is t be situated west f the Fx River, it will have t pass under the river; therefre sme tunneling thrugh rck will be required. Other imprtant waterways are the Big Rck Creek and the Kishwaukee River, which are nt as deep as the Fx River and wuld affect either surface r shallw tunneling cnstructin. These minr waterways and sme lakes ccur thrughut the site and will have t be cnsidered in the final ring lcatin. Anther significant gelgical feature is the Try Bedrck Valley lying alng the western edge f the regin. Althugh nt visible frm the surface, the valley cuts int the bedrck and is filled with glacial drift. In tunnel cnstructin, transitins between rck and drift are avided when practical because these different materials require different tunneling techniques. The unifrm till abve the valley is suitable fr either surface r shallw tunnel cnstructin. Factrs Related t Surface Cnstructin. Surface depsits vary ver the regin (fig. 21 ). Wedrn Frmatin tills predminate, but there are large areas f mixed cmpsitin and/r sand and gravel. The characteristics f these tills are generally suitable fr surface cnstructin (table 1). Cut-and-cver methds f surface cnstructin are cmplex. Althugh the tpgraphy f the regin is relatively flat, lcal variatins in elevatin f 50 feet r mre are cmmn, and the site slpes frm nrtheast and suthwest by abut 150 feet. Varius waterways and lakes in the area wuld restrict surface cnstructin; and mst likely, sme shallw tunneling wuld be required even fr a predminantly surface ring (fig. 2a). Mst imprtantly, such cnstructin wuld be highly visible, affecting highways, pwer lines, farmland, and frests. Nne f these factrs preclude the pssibility f a cut-and-cver apprach, but wuld nevertheless have t be cnsidered in chsing such a site. Factrs Related t Shallw Tunnel Cnstructin. Shallw tunnel cnstructin wuld take place in the glacial drift aviding sand and gravel if pssible at depths suggested by figures 19 and 20, abve the Glasfrd r Winnebag Frmatins. The Tiskilwa Till is especially 50 ILLINOIS STATE GEOLOGICAL SURVEY EGN 111

57 Cntur interval 100 feet t west f the Maquketa ersinal edge Cntur interval 50 feet t east f the Maquketa ersinal edge Figure 24. Depth t the tp f the Galena Grup. attractive because f its very unifrm cmpsitin ver the entire area. The till is a lcally thick, unifrmly mixed material with very lw permeability, similar t the clay till at the Fermilab site. An imprtant cnsideratin fr cnstructin in till f this area is the abundance f data available n drift cmpsitin frm existing well brings. The crss sectins given in this reprt are based n nly a fractin f the ttal data available. The extreme variatin in lcal drift cmpsitin is an imprtant factr t be cnsidered relative t tunneling perfrmance, equipment selectin, and cst. Althugh the well drilling data cnstitute an advantage, the wells themselves represent a ptential prblem. The tunnel will have t avid the wells r the wells will have t be replaced. This may be the mst imprtant envirnmental impact f a shallw tunnel. Factrs Related t Bedrck Tunnel Cnstructin. A deep tunnel wuld be cnstructed in bedrck belw the glacial tills. Figure 15 shws bedrck depths. The Galena-Platteville Dlmite is attractive fr tunneling because f its cnsistent and predictable cmpsitin. The Maquketa Shale Grup, by cmparisn, has a mixed cmpsitin cnsisting f shale and argillaceus r clayey dlmite. SSC: PRELIMINARY GEOLOGICAL FEASIBILITY REPORT 51

58 _ R7E ;- - T42N t ;.;.rck-..-, Mst suitable fr acceleratr ring. Tunnel in Galena-Platteville Dlmite; lies belw Maquketa shale. Sme limitatins fr acceleratr ring in Galena-Platteville Dlmite; lies directly belw glacial materials. 8s & Least suitable fr tunnel in bedrck; Galena-Platteville absent r highly fractured alng Sandwich Fault Zne. Figure 25. Relative gelgic suitability f the Galena-Platteville Dlmite fr tunneling. An imprtant advantage f cnstructin in the Galena-Platteville is that at sufficient depths a flat ring culd be situated entirely in this relatively hmgeneus medium. The lcatin f a flat ring wuld be abut 400 feet abve sea level r a depth between 250 and 500 feet deep (fig. 24). (At Fermilab, the tp f the Galena is abut 350 feet deep.) Figure 25 shws the relative suitability f the Galena-Platteville Dlmite fr tunneling. During the recrd-breaking prductin f the deep tunnel prject (TARP) in Chicag, a great deal f experience was gained that wuld apply t the SSC situatin. The prperties f rcks as well as general gelgic cnditins in the area prpsed fr the SSC ring site are expected t be similar t the cnditins encuntered by the TARP prject. 52 ILLINOIS STATE GEOLOGICAL SURVEY EGN 111

59 SUMMARY AND CONCLUSIONS A 20-TeV acceleratr culd be built in assciatin with the Fermilab site in a number f different ways, yet the pssibilities are reduced by sme general cnsideratins. The lwer ppulatin density west f Fermilab favrs a ring lcatin in that directin. The use f the Tevatrn as a preacceleratr (injectr) fr the SSC wuld require cnnecting the new machine t the existing site either by an injectin line that passes under the Fx River, r by an intersectin with the SSC. The gelgical factrs that wuld influence site selectin fall int at least three distinct categries, depending n the means f cnstructin emplyed fr the ring: surface cnstructin (cut-and-cver methds), shallw cnstructin (tunnel mainly in till), r deeper cnstructin (tunnel in bedrck). This reprt presents gelgic data necessary fr an initial evaluatin f ptential SSC sites using the Fermilab Tevatrn as an injectr. This favrable gelgic envirnment suggests that there are many ptential, lcal sites that merit further evaluatin. The final chice f ring lcatin will als depend n the acceleratr design and engineering factrs as well as n envirnmental, human, and financial cnsideratins. ACKNOWLEDGMENTS All f us have been infected by the excitement and enthusiasm that the high energy physics cmmunity has fr the prpsed Supercnducting Super Cllider. The imprtance f the SSC as an essential tl fr basic research has been made clear t us by Len Lederman, Directr f Fermilab, and the members f his staff. In particular, we wuld like t thank J. Lach, S. I. Baker, L. V. Culsn, A. J. Elwyn, R. Stefanski, and E. Treadwell, wh have answered ur innumerable questins abut high energy physics, the SSC, and hw it might be lcated relative t the existing Fermilab acceleratr cmplex. Many members f the Illinis State Gelgical Survey have taken part in the study and aided in the preparatin f this reprt. Rbert C. Vaiden and Jacquelyn L. Hannah were emplyed specifically fr this prject; Vaiden was supprted in part under cntract t the Illinis Department f Energy and Natural Resurces. Hannah cntributed significantly t the cmpilatin and preparatin f the maps and crss sectins. The study has drawn heavily frm published and unpublished reprts, ideas, data, and effrts f many past and present members f Fermilab and ISGS. This study has been strngly supprted by the Chief and Chief Emeritus f the State Gelgical Survey, Mrris W. Leightn and Rbert E. Bergstrm. SSC: PRELIMINARY GEOLOGICAL FEASIBILITY REPORT 53

60 APPENDIX. the bedrck and drift Selected sample descriptin lgs f water wells and test hles fr bth Cliff Neely N. 4 City f Batavia Drilled: May 1953 Lcatin: NW SW NW (1500 ft N line, 450 ft W line) Sec. 23, T 39 N, R 8 E; Kane Cunty Elevatin: 716 ft estimated frm tpgraphic map ISGS sample set n Summary sample study by G. H. Emrich 2/57 Thickness (ft) Bttm (ft) N sample SILURIAN SYSTEM Dlmite, very silty, light gray t buff, extra fine t very fine crystalline Dlmite, silty, light gray t light grayish buff, extra fine t fine, crystalline Dlmite, slightly silty, buff t light pinkish buff, extra fine t very fine, crystalline Dlmite, silty t very silty, buff t buffish gray, very fine t fine, crystalline Dlmite, slightly silty, buffish gray t grayish buff, very fine t medium, crystalline, prus Dlmite, silty, buff t buffish gray, very fine t fine, crystalline, trace f glaucnite ORDOVICIAN SYSTEM Cincinnatian Series Maquketa Shale Grup Dlmite, slightly silty, light gray t light buffish gray, very fine t fine, little medium, crystalline; trace f shale, light greenish gray, weak t tp Dlmite, slightly cherty, slightly silty t very silty, light gray t light greenish gray, very fine t fine, crystalline; trace f shale, very dlmitic, silty, light green, weak Dlmite, slightly cherty, slightly silty, light grayish buff, very fine t fine, crystalline; trace f shale, as abve Shale, dlmitic, slightly silty, brwn t grayish brwn, weak; little dlmite, very silty, brwn t light buff, very fine t fine, crystalline, speckled (black) Dlmite, slightly cherty, very silty, brwn t grayish brwn, very fine t fine, crystalline speckled (black); shale, as abve Shale, slightly silty, dlmitic, light greenish buff t buff, weak; dlmite, very silty, greenish brwn, light buff, very fine t fine, crystalline, slightly speckled (black) ILLINOIS STATE GEOLOGICAL SURVEY EGN 111

61 Dlmite, cherty, very silty, gray t grayish buff, very fine t fine, crystalline, slightly speckled (black) Shale, silty, dlmitic, brwn t grayish brwn, weak, tugh; little dlmite, as abve Shale, as abve Champlainian Series Galena and Platteville Grups Dlmite, slightly silty, buff t gray, extra fine t fine, crystalline line N samples Ancell Grup St. Peter Sandstne Sandstne, white t light buff, very fine t carse, runded, frsted, incherent Sandstne, white t light gray, fine t carse, runded, frsted, incherent Sandstne, cherty, slightly silty, white t light buff, fine t carse, runded, frsted, incherent Prairie du Chien Grup Oneta Frmatin Dlmite, slightly cherty (litic), slightly silty, light buff t pinkish buff, very fine t fine, crystalline Dlmite, slightly litic, silty, t medium, crystalline, dlmite crystals light buff t buff, very fine Dlmite, slightly cherty (litic), silty, pinkish buff t light buff, very fine t fine, crystalline Sandstne, slightly dlmitic, white t light buff, fine t carse, few granules, runded, incherent; shale, slightly sandy, light greenish gray t light gray, weak Shale, dlmitic, slightly cherty, red t brwnish red, little purple, weak Sandstne, white t light gray, fine t carse, few granules, runded, incherent, little cmpact; dlmite, slightly sandy, light gray t light pinkish buff, extra fine t fine, crystalline Dlmite, slightly silty, light gray t grayish buff t pinkish buff, extra fine t fine, crystalline Dlmite, very silty (carse), light gray t grayish buff, extra fine t very fine, crystalline CAMBRIAN SYSTEM Ptsi Dlmite Dlmite, silty t slightly silty, grayish buff t buff, extra fine t fine, crystalline, little geditic quartz Dlmite, slightly silty and argillaceus, buff t grayish buff, very fine t fine, crystalline, geditic quartz Dlmite, slightly silty, buff t brwnish buff, extra fine t fine, crystalline , ,025 SSC: PRELIMINARY GEOLOGICAL FEASIBILITY REPORT 55

62 Dlmite, slightly silty, buff t pinkish r reddish buff, very fine t fine, crystalline 18 1,043 Dlmite, silty t very silty, buff t buffish red, very fine t fine, crystalline, slightly sandy at base 23 1,066 Francnia Frmatin Shale, glaucnitic, silty, gray t light greenish gray, weak, little brittle; little dlmite at base, glaucnitic, extremely silty, gray, very fine t fine, crystalline 16 1,082 Sandstne, glaucnitic, dlmitic, light gray t light buffish gray, fine t medium, incherent, little cmpact Shale, glaucnitic, sandy, silty, gray t greenish gray, weak; dlmite at base, glaucnitic, very sandy, gray t greenish gray, fine, crystalline Shale, slightly glaucnitic and silty, gray t light greenish gray, weak 11 1, , ,125 Dlmite, very sandy, glaucnitic, gray t greenish gray, very fine t fine, crystalline; sandstne, glaucnitic, light gray, fine t medium, little carse, incherent 17 1,142 I rntn Sandstne Sandstne, dlmitic, slightly silty, light gray t light buff, fine t carse, incherent, little cmpact Sandstne, slightly dlmitic, light gray t light buff, very carse t carse, granules, little medium t fine, incherent, little cmpact 18 1, ,170 Sandstne, very silty, slightly dlmitic, light gray t light buff, very fine t very carse, few granules, incherent, little cmpact Sandstne, slightly silty, white t light gray, very fine t medium, little carse t very carse, incherent 10 1, ,215 Sandstne, dlmitic, light gray t light buff, very fine t medium, little carse t very carse, incherent, little cmpact Sandstne, white t light gray, fine t carse, runded, incherent Galesville Sandstne Sandstne, silty t slightly silty, white t light gray, very fine t carse, runded, incherent 20 1,300 Sandstne, white t light gray, very fine t fine, little medium t carse, runded, incherent 15 1,315 N sample 5 1,320 Eau Claire Frmatin Sandstne, white t light buff, very fine t carse, runded, incherent; dlmite, very silty, grayish brwn, very fine t 12 1, ,280 fine, crystalline 10 1,330 Sandstne, very silty, light buff t white, very fine t fine, little medium, incherent; little dlmite, very sandy, brwnish gray, very fine, crystalline Shale, slightly silty and dlmitic, buffish gray t gray, weak, little brittle t tugh Shale, slightly glaucnitic and dlmitic, gray t greenish gray, weak, little brittle Shale, slightly silty, buffish gray, weak 5 1, , , , ILLINOIS STATE GEOLOGICAL SURVEY EGN 111

63 ISGS 7 Drilled: July 30, 1971 Lcatin: SE SW SE (20 ft S line, 1650 ft E line f SE) Sec. 36, T 40 N, R 3 E; De Kalb Cunty, Elevatin: 865 ft Summary sample study by J. P. Kemptn and thers Reed, P. C, 1976, Data frm cntrlled drilling prgram in Bne and De Kalb Cunties, Illinis, EGN 77, Cre n Thickness (ft) Bttm (ft) QUATERNARY SYSTEM Wedrn Frmatin Tiskilwa Till Member Till, lamy clay, mttled yellw-brwn with pink clast, calcareus Till, lamy clay, red-brwn, calcareus Glasfrd Frmatin Sand, fine grained, brwn, well srted, with silt, sme rganic material; (at base) predminantly silt, sme clay, calcareus Till, lamy, mttled light yellw brwn, xidized, calcareus Clay, silty, gray brwn, calcareus Till, lamy, brwn with pink cast, calcareus Sand, lamy, pale brwn, with gravel, calcareus Silt, light yellw-brwn with live cast, sme rganics, bedded, calcareus Sand, fine t carse grained, well srted, light brwn gray, sme fine gravel, calcareus Sand, fine, well srted, light brwn gray, calcareus Sand, fine t medium, well srted., light brwn gray, calcareus Sand, very fine, pale brwn, calcareus Sand, fine, bedded, pale brwn, grading t silt, pale brwn, clayey tward base, calcareus Sand, fine t medium, yellw brwn, xidized, lse, nn-calcareus Sand, gravel, pebbly, with silt, light live brwn, smewhat calcareus, palesl Gravel, with pebbles, silt and clay, light yellw brwn, calcareus Sandy lam, live yellw, xidized, calcareus Sand, medium, light yellw brwn, with fine gravel, calcareus Sand, medium, light yellw brwn, with fine gravel and cbbles, calcareus ? 324? 10? ? Ttal Depth SSC: PRELIMINARY GEOLOGICAL FEASIBILITY REPORT 57

64 ISGS 25 Drilled: June 6, 1972 Lcatin: NE NE NW (5000 ft S line, 3000 ft E line) Sec. 13, T 40 N, R 7 E; Kane Cunty Elevatin: 785 ft Summary sample study by J. P. Kemptn and thers Reed, P. C, 1975, Data frm cntrlled drilling prgram in Kane Cunty, Illinis, EGN 75, Cre n Thickness (ft) Bttm (ft) QUATERNARY SYSTEM Mdern Sil Tpsil, sandy, dark gray.5.5 Equality Frmatin Clay, sandy, mttled gray brwn Sand, fine, silty, brwn Silt, clayey, gray, bedded Wedrn Frmatin Maiden Till Member Clay, silty, gray, till? 5 19 Sand, very fine grained, brwn gray, with wd fragments, clay seams Sand, silty, gray, with gravel seams Tiskilwa Till Member Till, gray-brwn with pink cast, nt xidized Till, silty, gray brwn, xidized Rbein Silt Silt, brwn gray, xidized, rganic (peat) Silt, gray, xidized, calcareus ? Glasfrd Frmatin Till, silty t sandy clay, gray t brwn gray, with gravel, bulders Till, clayey t sandy silt, gray t brwn gray with bulders, sand and gravel seams ORDOVICIAN SYSTEM Maquketa Shale Grup Shale Ttal Depth 58 ILLINOIS STATE GEOLOGICAL SURVEY EGN 111

65 REFERENCES Algermissen, S. T., 1969, Seismic risk studies in the United States: Wrld Cnference n Earthquake Engineering, 4th, Prceedings f the Chilean Assciatin fr Seismlgy and Earthquake Engineering, Santiag, Chile, reprint, p Algermissen, S. T., D. M. Perkins, P. C. Thenhaus, S. L. Hansn, and B. L. Bender, 1982, Prbabilistic estimates f maximum acceleratin and velcity in rck in the cntiguus United States: USGS Open File Reprt American Sciety f Testing and Materials, 1982, Annual Bk f ASTM Standards, Part 19, Natural Building Stnes, Sil and Rck, Philadelphia, Pa., p Baker, S., A. Elwyn, J. Lach, and A. Read, 1983, Tunneling beynd the Fermilab Site: Fermilab Reprt TM Berg, R. C, J. P. Kemptn, and A. Stecyk, 1984, Gelgy fr planning in Winnebag Cunty: Illinis State Gelgical Survey Circular 531, 69 p. Bergstrm, R. E., K. Piskin, and L. R. Fllmer, 1976, Gelgy fr planning in the Springfield-Decatur regin, Illinis: Illinis State Gelgical Survey Circular 497, 76 p. Brssman, J., 1982, Surficial gelgy f Kendall Cunty: M.S. thesis, Nrthern Illinis University. Buschbach, T. C, 1964, Cambrian and Ordvician strata f nrtheastern Illinis: Illinis Gelgical Survey Reprt f Investigatins 218, 90 p. Cleman, D. D., 1976, The rigin f drift-gas depsits as determined by radicarbn dating f methane: Ninth Internatinal Radicarbn Cnference, University f Califrnia, Ls Angeles amd San Dieg, June 20-26, Frye, J. C, H. D. Glass, J. P. Kemptn, and H. B. Willman, 1969, Glacial tills f nrthwestern Illinis: Illinis State Gelgical Survey Circular 437, 47 p. Gilkesn, R. H., and A. A. Westerman, 1976, Gelgy fr planning in Kane Cunty, in Gelgy fr Planning in Nrtheastern Illinis, II: Illinis State Gelgical Survey pen file reprt prepared fr the Nrtheastern Illinis Planning Cmmissin. Grss, D. L., 1969, Glacial gelgy f Kane Cunty, Illinis: Ph.D. thesis, University f Illinis at Urbana- Champaign, 21 1 p. Grss, D. L. (cmpiler), 1970, Gelgy fr planning in De Kalb Cunty: Illinis State Gelgical Survey Envirnmental Gelgy Ntes 33, 26 p. Hackett, J. E., 1960, Grundwater gelgy f Winnebag Cunty: Illinis State Gelgical Survey Reprt f Investigatins 213, 63 p. Heigld, P. C, 1972, Ntes n the earthquake f September 15, 1972, in nrthern Illinis: Illinis State Gelgical Survey Envirnmental Gelgy Ntes 59, 15 p. Hrberg, L, 1950, Bedrck tpgraphy f Illinis: Illinis State Gelgical Survey Bulletin 73, p. Hughes, G. M., P. Kratz, and R. A. Landn, 1966, Bedrck aquifers f nrtheastern Illinis: Illinis State Gelgical Survey Circular 406, 15 p. Husn, R., 1983, Ptential 20 TeV site in lllinis-de Kalb, in Slansky, Site Atlas fr the Supercnducting Super Cllider, Ls Alams Natinal Labratry. Kemmis, T. J., 1978, Prperties and rigin f the Yrkville Till Member at the Natinal Acceleratr Site, nrtheastern Illinis: M.S. thesis, University f Illinis, Urbana-Champaign, 331 p. Kemmis, T. J., 1 981, Imprtance f the regelatin prcess t certain prperties f basal tills depsited by the Lawrentide ice sheet in Iwa and Illinis: Annals f Glacilgy, 2, p Kemptn, J. P., 1963, Subsurface stratigraphy f Pleistcene depsits f central-nrthern Illinis: Illinis State Gelgical Survey Circular 356, 43 p. Kemptn, J. P., 1966, Radicarbn dates frm Altnian and Tw Creekan depsits at Sycamre, Illinis: Illinis Academy f Science Transactins, v. 59, n. 1, p. 39. Kemptn, J. P., J. E. Bgner, and K. Cartwright, 1977, Gelgy fr planning in nrtheastern Illinis, VIII. Reginal Summary: Illinis State Gelgical Survey unpublished maps and pen file reprt, prepared fr the Nrtheastern Illinis Planning Cmmissin. Kemptn, J. P., and D. L. Grss, 1971, Rate f advance f the Wdfrdian (late Wiscnsinan) glacial margin in Illinis: Stratigraphic relatins and radicarbn evidence: Gelgical Sciety f America, v. 82, p Kemptn, J. P., and J. E. Hackett, 1968a, The Late-Altnian (Wiscnsinan) glacial sequence in nrthern Illinis, in Means f Crrelatin f Quaternary Successins: Prceedings f the VII Cngress f INQUA, University f Utah Press, v. 8, p Kemptn, J. P., and J. E. Hackett, 1968b, Stratigraphy f the Wdfrdian and Altnian drifts f nrthern Illinis, in The Quaternary f Illinis: 14, p University f Illinis Cllege f Agriculture Special Publicatin SSC: PRELIMINARY GEOLOGICAL FEASIBILITY REPORT 59

66 Kemptn, J. P., R. C. Berg, H. D. Glass, L R. Fllmer, in preparatin, Revisin f the stratigraphy and nmenclature n nrth-central Illinis tills: A preliminary reprt. Klata, D. R., and T. C. Buschbach, 1976, Plum River Fault Zne f nrthwestern Illinis: Gelgical Survey Circular 491, 20 p. Klata, D. R., T. C. Buschbach, and J. Illinis State Gelgical Survey Circular 505, 26 p. Illinis State D. Trewrgy, 1978, The Sandwich Fault Zne f nrthern Illinis: Klata, D. R., and A. M. Graese, 1983, Lithstratigraphy and depsitinal envirnments f the Maquketa Grup (Ordvician) in nrthern Illinis: Illinis State Gelgical Survey Circular 528, 49 p. Landn, R. A., and J. P. Kemptn, 1971, Stratigraphy f the glacial depsits at the Natinal Acceleratr Labratry site, Batavia, Illinis: Illinis State Gelgical Survey Circular 456, 21 p. Lineback, J. A., 1979, Quaternary depsits f Illinis: Illinis State Gelgical Survey Map. McCmas, M. R., 1969, Drift thickness f De Kalb Cunty: Illinis State Gelgical Survey unpublished pen file map. McGinnis, L. D., J. P. Kemptn, and P. C. Hejgld, 1963, Relatinship f gravity anmalies t a drift-filled bedrck valley system in nrthern Illinis: Illinis State Gelgical Survey Circular 354, 24 p. Meents, W. F., 1960, Glacial-drift gas in Illinis: Illinis State Gelgical Survey Circular 292, 58 p. Nuttli, 0. W., and R. B. Herrmann, 1978, U.S. Army Engineers Waterways Experiment Statin Miscellaneus Paper S Piskin, K., and R. E. Bergstrm, 1967, Glacial drift in Illinis: Thickness and character: Illinis Gelgical Survey Circular 416, 33 p. Piskin, K., and R. E. Bergstrm, 1975, Glacial drift in Illinis: Thickness and character: Illinis Gelgical Survey Circular 490, 35 p. Slansky, R., 1983, Site Atlas fr the Supercnducting Super Cllider, Ls Alams Natinal Labratry, Ls Alams, New Mexic. Terzaghi, K., and R. B. Peck, 1967, Sil Mechanics in Engineering Practice (secnd ed.): Jhn Wiley and Sns, New Yrk, 729 p. Wickham, S. S., 1979, The Tiskilwa Till Member, Wedrn Frmatin: A reginal study in nrtheastern Illinis: M.S. thesis, University f Illinis, Urbana-Champaign, 229 p. Wickham, S. S., and W. H. Jhnsn, 1981, The Tiskilwa Till, a reginal view f its rigin and depsitinal prcesses: Annals f Glacilgy, 2, p Willman, H. B., 1971, A summary f gelgy in the Chicag area: Illinis State Gelgical Survey Circular 460, 77 p. Willman, H. B., 1973, Rck stratigraphy f the Silurian System in nrtheastern and nrthwestern Illinis: Illinis State Gelgical Survey Circular 479, 55 p. Willman, H. B., E. Athertn, T. C. Buschbach, C. Cllinsn, J. C. Frye, M. E. Hpkins, J. A. Lineback, and J. A. Simn, 1975, Handbk f Illinis stratigraphy: Illinis State Gelgical Survey Bulletin 95, 261 p. Willman, H. B., and J. C. Frye, 1970, Pleistcene stratigraphy f Illinis: Illinis State Gelgical Survey Bulletin 94, 204 p. Willman, H. B., and D. R. Klata, 1978, The Platteville and Galena Grups in nrthern Illinis: Illinis State Gelgical Survey Circular 502, 75 p. 60 ILLINOIS STATE GEOLOGICAL SURVEY EGN 111

67 GLOSSARY ablatin till after depsitin, till has been mdified by water and mass wasting prcesses. Ablatin till may be mre sandy and less densely cmpacted than unmdified till. accretin gley fine-grained and rganic materials, which slwly accumulate in prly drained depressins with intermittent water saturatin. alluvium the general term fr all sediments depsited in land envirnments by streams. argillaceus rck cmpsed f r cntaining clay-size particles; rck cntaining an appreciable amunt f clay. artesian cnditins where an aquifer is cnfined between impermeable layers and the water in the pres f the aquifer is nt pen t atmspheric pressure, but ccurs at greater pressures. artesian well ne in which the water level rises abve the tp f a cnfined aquifer, whether r nt the water flws at the land surface. attenuatin capacity the ability f a material t adsrb and return certain anins and catins in an exchangeable state. basement the crust f the earth belw sedimentary rcks. In primarily f red granite. Illinis, these rcks cnsist catin exchange capacity the capacity f a sil t srb r hld catins and t exchange species f these ins in reversible chemical reactins; imprtant fr studies f sil and nutritin studies, as well as fr sil genesis and cntainment attenuatin. fertility chert hard, dense, cryptcrystalline, sedimentary rck, cmpsed predminantly f silica. clluvium a bdy f sediment that has been depsited by any prcess f mass wasting r by verland flw. crss sectin a diagram r drawing that shws gelgic features transected by a given plane. dlmite a variety f limestne rich in magnesium carbnate. drift a general term applied t all rck material (clay, sand, gravel, bulders) transprted by a glacier and depsited directly by r frm ice, r by water flwing frm a glacier. drusy cntaining many small, irregular cavities lined with small prjecting crystals. end mraine a ridge-like accumulatin f drift, depsited by a glacier alng its frnt margin. esker a bdy f ice-cntact stratified drift shaped int a lng narrw ridge, cmmnly sinuus. fld plain that part f any stream valley that is inundated during flds. fluvial prduced by the actin f streams r rivers. SSC: PRELIMINARY GEOLOGICAL FEASIBILITY REPORT 61

68 frmatin in lithstratigraphy, the primary rck units that pssess distinct lithlgic features, reflecting a genetic relatinship. friable easily brken, prly cemented rck. glaucnite dull green, earthy r granular minerals f the mica grup, an irn-clay indicative f a marine envirnment. kame a bdy f ice-cntact stratified drift shaped as a shrt, steep-sided knll r hummck. kame mraine a terminal mraine that cntains numerus kames. kettle a clsed depressin in drift, created by the melting ut f a mass f underlying ice. lacustrine prduced by r frmed in a lake. leachate a slutin btained by leaching; water perclated thrugh sil cntaining sluble substances, and cntaining amunts f these substances in slutin. lithlgy a descriptin f rcks based n characteristics such as clr, structures, mineralgic cmpsitin, and grain size. less wind-depsited silt, usually cntaining sme clay and sme fine sand. member subdivisin f a frmatin, generally f distinct lithlgic character r f lcal extent. mineral a naturally frmed chemical element r cmpund having a definite chemical cmpsitin, and usually, a characteristic crystal frm. nnattenuated ins ins which are nt adsrbed nt materials that they pass thrugh due t their chemical cmpsitin and cncentratin. litic cmpsed f small, rund accretinary bdies, generally f calcium carbnate. utlier area r grup f rcks surrunded by utcrps f lder age. utwash plain sheet-like depsits f sand and gravel transprted away frm the ice by meltwater streams alng the frnt f the glaciers. peat a brwnish, light weight mixture f partly decmpsed plant tissues in which the parts f plants are easily recgnized. perched water table uncnfined grundwater separated frm an underlying main bdy f grundwater by an unsaturated zne. permeability capacity f a material t transmit a fluid. Degree f permeability depends upn the size and shape f the intercnnecting vids. It is measured by the rate at which a fluid f standard viscsity can mve a given distance thrugh a given interval f time. release rate rate at which attenuated ins are released int the grundwater. sil the uncnslidated mineral matter n the surface f the earth; it has been subjected t and influenced by genetic and envirnmental factrs f parent material, climate, rganisms and tpgraphy all acting ver a perid f time. 62 ILLINOIS STATE GEOLOGICAL SURVEY EGN 111

69 slutin cllapse cllapse due t the slutin f underlying rck, typically in limestne. stratigraphy that branch f gelgy that treats the frmatin, cmpsitin, sequence and crrelatin f the rck units as part f the earth's crust. tectnic prduced by earth mvements. Tesla a unit f magnetic field strength equal t 10,000 Gaus. till a nnstratified glacial depsit cntaining a wide range f grain sizes. till plain an extensive area, with a flat t undulating surface underlain by till, which is cmmnly cvered by grund mraine and subrdinate end mraines. tpgraphic map map shwing the tpgraphic features f a land surface generally by means f cntur lines. transmissibility rate f flw (gal /day) thrugh a vertical sectin f an aquifer with a defined width and hydraulic gradient. valley train a lng narrw bdy f utwash cnfined within a valley. SSC: PRELIMINARY GEOLOGICAL FEASIBILITY REPORT 63

70 .. and Graphic Artists: Jacqueline Hannah, Pamella Fster Typgrapher: Gail Taylr Kemptn, J. P. (Jhn P.) Gelgical-getechnical studies fr siting the Supercnducting Super Cllider in Illinis : preliminary gelgical feasibility reprt / J. P. Kemptn. thers. Champaign, I L : Illinis State Gelgical Survey, p. ; 28 cm. (Envirnmental gelgy ntes ; 111) 1. Gelgy Illinis, Nrtheastern. 2. Particle acceleratrs Siting- Illinis. 3. SSC. I. Title. II. Title: Preliminary gelgical feasibility reprt. III. Series. Printed by authrity f the State f Illinis/1985/3000

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