551.4 F94p cop. 14 FRYXELL THE PHYSIOGRAPHY OF THE REGION OF CHICAGO UNIVERSITY OF . ILLINOIS LIBRARY AT URBANA-CHAMPAIGN The person charging this material is re- sponsible for its return to the library from which it was withdrawn on or before the Latest Date stamped below. nutilafion. and Theft, for disciplinary action and may result in dismissal from the University. To renew call Telephone Center, 333-8400 UNIVERSITY OF ILLINOIS LIBRARY AT URBANACHAMPAIGN Jul l 9 W DEC 03 DEC o " D[C 2 2?0)5 THE PHYSIOGRAPHY OF THE REGION OF CHICAGO THE UNIVERSITY OF CHICAGO PRESS CHICAGO, ILLINOIS THE BAKER & TAYLOR COMPANY THE MACMILLAX COMPANY OF CANADA, LIMITED THE CAMBRIDGE UNIVERSITY PRESS THE MARCZEN-KAISUSIIIKI-KAISHA THE COMMERCIAL PRESS, LIMITED THE PHYSIOGRAPHY OF THE REGION OF CHICAGO By F. M. I in XELL DEPARTMEN1 "I <■! >H.<".1 . UJGUSTANA I OLL1 Gl ROCK ISLAND, ILLINOIS PREPARED in The University of Chicago Local Community Research Committee, and the Chicago Commonwealth Club, for the Committeeon General Surveys of the CHICAGO REGIONAL PLANNING ASSOCIATION THE UNIVERSITY OF CHICAGO PRESS ( UK \<.o • ILLINOIS COPYRIGHT 1927 BY THE UNIVERSITY OF CHICAGO All Myitis Reserved Published April 1927 (■»in,,,/, ( j'i/ U n ( ,»lv,,..i;,„„; ; • INTKOIHCTION ■ ■/ 7~ II I \ tin i hicago Regional Planning MM/ Association started its work the officers ■/■/ immediately recognized the need for a V V correct base map of the region. For con- i of study they selected an area with ap- proximately a fifty-mile radius, an arm which in- cluded parts of three states, all or parts of fifteen counties, and over two hundred and fifty cities and villages. Sections of the ana had been carefully mapped, but for some parts there urn no availabli maps, and on no one map was there the complett in- formation needed. Thefirsi undertaking of the Asso- ciation's Committee on General Surveys was the preparation of such a map, underthedirectionof Pro- fessor J. Paul Goode, of the University of Chicago. To accompany the map, each department of the Regional Planning Association needs certain gen- eral information on the physical geography of tht region, so that il may lay its plans carefully and on a correct foundation. Therefore the present study was undertaken which delineates in a broad way the outstanding natural features of tin region and emphasizes especially such as have bearing upon n gional planning. The preparation of this work, as well as of the map, was made possible by the joint financial con- tribution of the Chicago Commonwealth Club and tin ( 'ommittee on Local Community Research of the I 'niversity of < 'hicago. . I grateful acknowledgmt nt is accordingly made to both of these organizations. In this report tin area covered by the base map is designated as the "region of Chicago," or the "t hicago region," although the latter term has been used by other authors in a more restricted senst to nly to tin area covered by the Riverside, Chi- cago, Des Plaines, and < alumet topographic maps published by tin United States Geological S This region of Chicago lies at the head of Lakt Michigan and embraces thi northeastern con Illinois, tin southeastern corner of II isconsin, and tin northwestern corner of Indiana. More specifi- cally, it includes the counties of Lake, McHenry, t ook. Pa Page, Kane, Kendall, Grundy, II' ill, and Kankakei m Illinois; the counties of Racine, Keno- sha, and tin eastern two-thirds of Walworth in Wisconsin; and the counties of Lake, Porter, and Laporte in I ml in mi. Discussion is extended nt times tn outlying counties, notably Starke County and the northern part of Pulaski, Jasper, and New- ton counties in Indiana; and the northeastern i>art of Livingston County in Illinois. The city of Chi- cago occupies n central position with referex this region. The inception of this study is due to Dr. J. Paul G le, of tin' University of Chicago, tht plan developed in the report is essentially his, and he has given the work his constant personal atten- tion. This invaluable supervision and the kindly in- terest which have accompanied it the writer takes tin greatest pleasure in acknowledging. To Professor -I II />'/>•/:. of the University of Chicago, who has shared with lh. Goode the super- vision of this study, the writer gratefully acknowl- edges his indebtedness for help and counsel II also expresses his deep appreciation to Dr. M M l.i ighton, director of the Illinois Geological Survey, who not only placed at the disposal of the writer much unpublished data in the possession of tht Survey, but also volunteered many suggestions which Imn been incorporated in this study. Acknowledgments are also made to l> II v Smith and Dr. I.. II. Smith, of tin agronomy de- partment of the University of Illinois, for max* to unpublished soil data of the Agricultural Experi- ment station, and for courtesies extended the au- thor on tin occasion of his visits to Urbana; to Pro- fessors D. •/. Fisher, II'. /'. .loins. Paul MacClin- tock, George D. Fuller, and II. C. Cowles, of the University of Chicago, and particularly to the officers of the Chicago Regional Planning Associa- tion, nil of whom hair generously assisted the writer ccasions. Assistance is also acknowl- edged from the United States Gt >bgical Survey, the Bureau oj Soils of the United States Departi Agriculture, tht Indiana and Wisconsin Geological surveys, and the United States Lake Survey. .1 complete statement of indebtedness to the great geological literature dealing with the region of Chicago is, of course, impossible; but in tin text citations are made to the works from which most important data have been obtaim I. and a Si Bibliography appears n* the closi of tht r>jinri. The standard publications of < 'hamberlin, I Taylor, Salisbury, Alden, Martin, and G Idthwaii have constittded an invaluable mine of information. I M Fryxell UNIVERSITY OF ILLINOIS LIBRARY AT URBANA-CHAMPAIGN tabu; <>i contents Lisa i 'i [llusth vn [. General Physiographk Fi iti res IlNd Their Origin i II. 'I'm l.\ki Plain, \ Gri \ i l\m stri \i. Am \ . II III. 'I'm Laki Border Upland, a Residential and Recreational Area hi IV. Tin (iin u.<> ()i n.i i. mi Gri \ i Pass ro i m Mississippi Vallei Is V. Tin Valparaiso Upland, i. Continental Divide VI. Tin Manteno Plain VII. Tin Morris-Kankakei Basin, *. Potential Recreational Belt . *> \ III T i b Upland, vn A.gru i lti ral \ki \ 28 l\ I.nki M w vnd [ts Shori Line 80 X. Tin Bed Rock and Its Surface, a Buried Landscapi .">? XI. Tin Si i;i \m Mat] rials, Basis i r \ . . k- i < cjltural Wealtb I-.' \ll Tin Geological Resources of THi Region 17 Si 1. 1 i I 1 D BlBL RAPH1 ">1 I \i>i \ . . . .">:'. LIST OF ILLUSTRATIONS 1. Index Map 2 2. Natural Divisions of thi Region of Chicago 3 :;. Cross-Sections through the Region of Chicago ... f 4. Diagrammatic Cross-Section through the Gri it Lakes Region 4 .'>. Block Diagram, Showing Basin Character of the Strata i\ thi Gre \r Lakes Region 4 (>. Geologic Map of the Great Lakes Region .... ."> 7. Glacial Map of the Central Part of the United Statj s <> s. Sketch Map of Lake Michigan Region, Showing Position of the Green Bay and Lake Michigan Lobes of the Latest Glaciation 7 !). Diagram Explaining Origin of Lark Michigan Basin ... 7 10. Wind Rose for Chicago 10 1 1. Ski i< ii Showing Changes in the Course of the Calumet River 14 12. Contour Map of the Lake Michigan Basin 31 13. Diagram Explaining the Shore Drift in Lake Michigan . 32 11. Geologic Map of the Region of Chicago 38 15. Map Showing Average Thickness of Surface Materials ... 40 16. Collecting Areas for the Artesian Waters of the Region of Chicago 4!) 17. Diagram Illustrating Artesian Conditions 50 I. Glacial Map of the Region of Chicago . II. Relief Map of the Region of Chicago III. Drainage Map of the Region of Chicago IV. Generalized Soil Map of thi: Region of Chicago Y. Base Map of th] Region of Chicago facing 10 facing IS facing 4<> inside hark < over Chapter I GENERAL PHYSIOGRAPHIC FEATURES AND THEIR ORIGIN Til K region of < Chicago lies in whai is know n in a physiographic classificati Fthe United States as the Central Lowland, 1 an area embracing a large pari of the vast basin which stretches from the Appalachian highlands on the easi to the Rocky Mountains mi the west. Four features <>f the Central Lowland are of out- standing prominence: First, it i- everywhere low and flat of surface. Illinois is the lowest of the states within its bounds, with a mean elevation above sea-level of only 600 feet; Indiana is 100 feel higher; and Wisconsin, notably higher than either Illinois or Lndiana, has a mean elevati f 1,050 feet. Second, throughoul the greater pari of the Central Lowland the bed rock is deeply buried beneath a mantle of unconsolidated glacial deposits see Fig. 7). Third, the province is drained by two extensive river systems, the St. Law- rence on the east and the Mississippi on lli<' west. Fourth, the northeastern pari of the province is a lake region, being occupied by thousands of small glacial hike-, and by the Greal Lakes, the largest system of fresh-water bodies in llu- world. In almost the exacl geographic center of lliis low- land is the region iif ( Ihicago. The si rategic importance of its location i- due t<> ;it least four significant facts: lln the Central Lowland is probably the richest agri- cultural belt in the world, and in the center of it lies the region of Chicago. 2 The general flatness of the Cen tral Lowland has facilitated the rapid extension of rail road and highway lines with the minimum of expense and difficulty. These railroads and highways concen irate mi Chicago because east-and-west traffic is here compelled t" turn southward around the head of Lake Michigan, thus meeting and crossing at tin- common, geographically determined focus. (3 Here i- a direct point "I" contact between the lake region with it- great water-transportation system and the agricultural region with its highly developed railroad system I TheCon- tinental Divide between the Mississippi and the St. Lawrence drainage systems crosses the region of Chicago (see drainage map, Plate III , Therefore the region has the advantages of both sj stems, and profits by whatever \ M Fenneman, "Physiographic Divisions of tfii i \ \ I I u \l. DIVISIONS OF III! REGION "I CHK \< ■< > Wli I III IK ORIGIN Alternating ridges, plain-, ami valleys enter the aica at the north and. roughly paralleling the -linn- of Lake Michigan, swing southeastward around tin- head of the lake. Tin- st nam- emphasize the alternate higher ami lower land by flowing either parallel to the shore of the lake or at right angles In it. This -ana- pattern i- brought out in the distribution of soils see generalized soil map. Plate l\ ; h is -I strikinglj shown, how- ever, mi the relief map Plate Ik ami mi the glacial map (Plate I Si\ -mli concentric belts or zones an- recognized, ami each i- discussed in a separate chapter. They are as follows: 1. The Lake Plain •.'. The l.ak,- Border Upland :;. The ValparaisoUpland I. The Mante,,,, Plain 5. The Morris Kankakee Basin (i. The Outer Upland Lake Michigan is regarded as a special province, ami its description follows the discussion of tin- la ml divisions. How tin- i ia I ma I divisions originated, and what has happened to them up to the present i- an intensely Fascinating story even In those who are not particularly interested in geology, because of the direct bearing human affairs today. ORIGIN IND ell IB Mil l( OF BED ROCK The existence in the Central Lowland of a -eric- of strata ,«f limestone, sandstone, ami -hah-, containing marine fossils, indicates that Ihi- part ■>!' the continent was in ancient geologic time- repeatedly depressed be low sea-level so that seas -t I over tie area. For de- posits to have accumulated at the bottom of these seas, as thick as those we now find the marine conditions must certainly have hail a duration of millions <>f year-. I \l 1917 ■ PHYSIOGRAPHY OF THE REGION OF CHICAGO Finally the sea bottom emerged lf time elapsed, compara- ble in length to that duringwhich theregionwas under the sea. Since the lifting of the sea bottom the centra] part of the continent lias been subject to erosion. The uplifted surface was slowly dissected into valleys and hills; under atmospheric conditions soils accumulated; and a landscape of rugged rock valleys and ridges was developed not unlike that found al the presenl time in southwestern Wisconsin. ORIGIN <>F Till. GRI VI' LAKES This age-long process of erosion was interrupted in recent geological time by changes in climate which brought on the Glacial Period, a time of vast importance in the history of the region of Chicago. Great con- tinental glaciers, nourished by persistent snowfall, spread outward for hundreds of miles from their centers in Canada, and it is now definitely established that the central part of the United States was invaded not once lint repeatedly by ice sheets from the north, and that III the Great Lakes region the rock strata do not lie Hat but dip inward from all directions toward the center of the state of Michigan (see Fig. .">>. in a saucer-like struct lire, around the rim of which one formation after another comes to the surface (sec Fig. 6). The hardness of the various formations in the Greal Lakes region is not the same; for this reason, it is be- lieved, valleys were developed by erosion in the softer rocks, such as the Devonian shales, and highlands were left on the harder rocks, such as tin' resistant Silurian i Niagara l limestone. In the Devonian outcrop, a north- south strip underlying Pake Michigan, a large valley was developed, bordered on either side by highlands of Silurian and Mississippian strata. Similar valleys in the soil rocks, and highlands on I he hard rocks, were de- veloped throughoul the (.real Lakes region. these invasions alternated with equally Ion- intervals when the region was ice free. The most extensive ice sheet, the kansan. reached as far south as northern Kansas and Missouri. Each successive readvance after the Kansan fell short of its predecessor, and more or less completely effaced the traces of earlier glaciations. Though the region of Chicago was probably glaciated repeatedly, it is the latest invasion of ice, the Wisconsin, which gave our area practically all of its present physi- ographic features (see Pig. 7). It occurred so recently, in terms of geologic lime, that, were the covering of vegetation Stripped from the area, the landscape would appear very much as it did when the laic Wisconsin ice sheet receded, perhaps twenty-five thousand years ago. It is therefore possible to interpret with considerable GENERAL I'll YSK >< ,K AI'lIM FEATURES AND TIIKIli ORIGIN .i.il div isiona ..f the region of Chicago. I '■ "» foil PHYSIOGRAPHY OF THE REGION OF CHICAGO Outer- Up/oncf My/ocrro/s o Upland LolzeBorder I^a/za Upland Michigan ■ ^ Dc p ,^ i [1 1 ) \',S>1 «o. 1 .^^^ J ■ ij \lll ! nTiflTntfi — i" nc SECTION A-, Michi ^^-S^ rr ■ ' ; s^PiS Fig. t. — Rock Formations in the Greal Lakes region. Note, first, how the rocks dip inward to form a saucer-like structure; second li<>« the lake basins have been excavated largely from the outcropping edges of the soft rocks: and, third, how I he- resistance of the Niagara formation gives rise to an escarpment that separates Green Bay from Lake Michigan and Georgian Bay from Lake Huron. Similarly, it separates Lake I'n.. .1. -Strata in the Greal Lakes region. Block diagram indicates the basin character of the strata. The lakes lie chiefly Devonian and Ordovician strata, which are less resistant than the adjacent strata. Note the position of the Niagara escarpment, i ing as the peninsula cutting off < ieorgian Bay, as Grand Manitonlin I. and as the Door peninsula cutting off (inni Ua.\ . GENERAL PHYSIOGRAPHIC FEAT1 RES WD THEIR ORIGIN The great ice sheets crepl down from the north over landscape of major valleys and divides, already de- eloped by prolonged erosi f the bed-rock surface, u.l naturally the direction of flow of the ice was de- ■rmiiird largely by these major valleys and divides, oncenl ral ion of I he ice in I he \ all > bee e distinctly lobate in character. Pushing trough and beyond these great valleys, the lobes < 1« ,_ loyed widely, in some cases merging with adjacent il»-s. The region of * 'hicago was largely co\ ered by I he eploying Lake Michigan lobe, but lw> other lobes npinged upon it- northern margin in Wisconsin: the in t urn corresponde I t" an outcrop of soft rock strata. Bach lobe tended to deepen and broaden the valley it occupied, and the valley which now contains Lake Michigan i- believed i<> have been deepened 500 :»>n feet. The material thus removed, as well as that ob- aused the glacier tained farther to the north, was carried to the margin of the ice and there deposited in the long, irregular ridges known as "terminal moraines." Thus the basins of the Great Lakes were formed by two processes i the deepening bj glacial erosion, and 2 the building up iif their margins by glacial deposition see Fig 9 The Great Lakes basins fall into two groups: I ,1-een Bay and the small intermediate Delavan (see Fig. those excavated largely from the soft Devonian strata, Each of these lobes corresponded to a lowland which and (2 those excavate I largely From thesofl Ord ivician ^] Pennsy /van/an YfflffJh D&\/o/->fc7i Mississippian \'tf]\ ^ 5//^nbn | ] Orc/< Pre -Combrior-. ov/c/crn PHYSIOGRAPHY OF THE REGION OF CHICAGO strata. The basins of tli<' groups arc separated by the Niagara escarpment, a ridge of limestone which was too resistanl for the ice to quarry away. This prominent ridge swings in a semicircle all the way from eastern Wisconsin to northern New York and strikingly em- phasizes the great saucer of rock in which the Greal Lakes lie (see Fig. 5). The Niagara escarpment sepa- rates Green Bay from Lake Michigan, Georgian May from Lake Huron, and Lake Ontario from Lake Erie. lower land that encircle Lake Michigan and cross the region of Chicago. At one stage of the retreat of the Wisconsin glacier, water issuing from the melting fronts of three adjacent lobes — the Lake Michigan, Saginaw, and Erie — escaped through the lowland now occupied by the Kankakee River. The escaping water entered the valley of the Illinois River in the vicinity of Morris. Illinois, and fol- lowed this drainage channel to the Mississippi. A termi- |: ::.•:::! Oreo covered hu latest r 1 area covered by various The "Drift/ess area" a portion X :::::; : | glgciyville, Illinois. Its retreat was interrupted by repealed halts and re- advances. Where it retreated steadily its deposits look t he form of a ground moraine, or t ill plain, characterized by level or gently rolling surface. Where it hailed or re- advanced it piled up a ridge of debris under its edge, a terminal moraine. Because of the erratic character of its retreat, the lobe built up a scries of plains and ridges, now recognizable in the concentric belts of higher and nal moraine which crosses the Illinois Valley at right angles just west of the region of Chicago al Marseilles, known as the "Marseilles moraine," probably ponded the water for a time, forming a temporary lake in the Morris Basin known to geologists as Lake Morris. In the Indiana portion of the Kankakee Valley ponding also appears to have occurred, giving rise to shallow- temporary lakes and marshes, many of which still exist or have been drained luil recently. In both of these areas, extensive beds of sand were deposited. In the por- tion of the Kankakee Valley between the Illinois-Indi- ana state line ami the mouth of the Kankakee River GENERAL PHYSIOGRAPHIC FEATURES AND TIIKIR <>RH.I\ -tri|> away much of the glacial moraine, in sonu ilnun In bed rock. Tlii> glacial outflow lia> been t be "Kankakee torrenl ." At last the ice retreated into ened Lake Michigan Basin. In I i Plaines, Illinois, and Mississippi rivers. There must 9 have been a low place in the moraine ju>i wesl <>f Chi- I cago through which the lake overflowed and ^> initiated this line of discharge. The lake was repeatedly lowered, w greatly deep- probably through the cutting down of this outlet. «n Finally, as the ice retreated northward, the lake ceased discharging southwestward through the Chicag itlet, underwent a series of complex stages thai need not be outlined here, attained itspresenl level and place of dis charge into the St. Lawrence drainage area, and so be- came Lake Michigan. ■/■ffJ^y&fr v Surface of La Ice ^ -r^irrrT Fio 9 I Preglacial river valley; B: Lake Basin. The basin is due: Brat, to the deepening and widening ol the preglacial river vallej , and, se I, to the heaping ol - aine about its margins. On iES IN I III REGION Ol I HICAGO worthy changes have occurred since the ice sheel completely lefl the region. I Prominent | bluffs and ravines have been developed along the laki fr. »iil between Winnetka and Waukegan by erosi f the shore line. (2) Extensive deposits of sand have been Fio 8 Green Baj and Lake Michigan lobes ol Wi -. Between the two large lobes is the Delavan lobe, in Hi northwest corner of the region ol ' hicago. which is shown in the made along the shore al the head of Lake Michigan. 3 beavj line. Modified fr U.S. C <■ ' This sand-filling in northern Indiana has been buill up into a rhagnificenl assemblage of dunes. I 1 Some of the the fronl of the ice and the group of abandoned terminal | arger streams have deepene I their valleys to a min >r moraines thai had been buill around the head of the exten1 .-, Thepresenl soils have been formed upon the basin, there developed a lake which geologists have surface of the deposits lefl by the glacier named "Lake Chicago." At one time this lake had a level al t sixtj feet higher than Lake Michigan. In- vegetation of thi region wso like the present lake, Lake Chicago discharged south Because the region of Chicago constitutes a meeting westward to the Gulf of Mexico by way of the Des gr I for the plants of many regions, the botanical - G I Ekblaw and L. F. Athy, "Glacial Kankakee Torrent in Northeastern II is," Bulletin I WW I June 10 I''. 1 . 117 88 ■ The Following ;ir.- valuable references dealing with the vegetation of thi ires It I Cowles " Hie Ecological relations ol tion of . the Sand Dunes of Lake Michigan /■ I \\\ll 1809 96 111 167 80S Wl 108 101 01 1 • II leorge D. Puller, The I ' hicago, in.'-. PHYSIOGRAPHY OF THE REGION <>K CHICAGO features are < ,f spe cia 1 interest . The natural v< ■getation of the area may be resoh ed chiefly into til !■(■(■ com- ponents : 1 1 > retui me 1 plant l migrants from tl ie south- eastern pari ofth< ■ I nited State- thai had 1 ,(•( in driven • mi duri ng II te gla lion: (2) "hangovers" of northern species thai have pei ■sisted 1< ..ally since gl; ICl ill times: and (.'!) a fev migi he semiarid s< Hit Invest. Pkolo by i i D I An Dih Forest, n*ear New Lenox, [ll , Typical of the Vegeta noN in i he Region of Chicago. :*-rv.* "'• '- r; - v, ■ . -^ Prickli Peab (Optunia rafinesquii . \ Native of the Ai west, ts Foi mi in mi. Swn-Di si: Ann OF Ism Melting Pot oi \ egei nn'\ is the Region Back in the period of glaciation, when arctic condi- tions prevailed over the northern part of the United Stales, the refrigeration resulted in a ureal southward exodus of plant and animal life. The colder temperature <• litions enabled the plants of the far north to migrate south to the centra] part of the United States, where they replaced the former vegetation thai had been driven into the southeastern part of the United States. After a -real lapse of time the climate moderated, the ice began its withdrawal, and there was again initiated a great migration of flora — this time, however, north- ward. Unable to endure the warmer climate, the north- ern vegetation retreated again to high latitudes: and the vegetation native to the middle latitudes made its way hack again to the region whence it had been expelled. At the present time these returned migrants dominate the region of Chicago. They include such well-known species as the white oak (Quercus alba), the red oak {Quercus rubra), the red maple (Acer rubrum), the shag- bark hickory (Carya ovata), and a hosl of others. In certain restricted localities, however, of which the sand- dunes region of northern Indiana affords I he l>e-t example, a number of specie- of plants from the far north still linger by virtue of a favorable environment. Of this class excellent examples are the jack pine [PitlUS Banksiana) and several other conifers, the liearherry (Arctostaphyhs Uva-Ursi), the dwarf birch (Betula ila). and the cranberry (Vaccinium macrocarpon). ■purrn ■ third strain which enters into the floral composi- f the area, the migrants from the semiarid soul li- the prickly pear cactus (Opuntia Rafinesquii) and GENERAL I'll YSM ><,R.\rilI< FEATURES AND IIIKIK MUHilX the western reed grass ( alamot Ufa longifolia are g I examples. The cosmopolitanism of the vegetation in the area is best displayed in the sand-dune region of northern [ndiana, which Professor II. C. Cowles, eminent ;mi- thority on thai region, has ;i|>lly termed ";i veritable floral melting pot." Professor Cowles's description is a vivid picture of the unusual conditions that ther ■ m There are fe« places on < «ur continent where so manj species • •! plants are found in s,, small compass. I pari because of the wide diversitj of conditions prevailing Vmong ~ii«li plants of the < Canadian Fores) and in mini are tin- Iwiii Bower, the glandular willow, the poverty grass, and the northern rose. Northern plants are particularly character- istic "I the 'lunc- swamps, and embrace such interesting species ;i- the larch, bunchberry, dwarf birch, sage willow, numerous orchids, cranberry . i Kese species are fo dune region. 1 The climate ipted for Inn leaf, and man} here for many in region if. .it a Many of excellently This is due TABLE I ( mm. i nous n ' Hi. igo* f J - | < , \ £ < \ 7 1 ; | 6 Average maximum temperature Fahrenheit Mean temperature 31 18 1!) H Hi si I 0" 13 36 ■>» \l 17 68 .' 61 t? \l 16 ■ ?8 65 51 19 M 15 72 74 67 en -\\ 1 1 72 BO m; -u 12 7-.> 3 36 78 72 m: 1 .' 72 3 •-'! 72 65 58 S\V. 14 .'! Il!l 61 .»! t7 -U IS B3 i 58 17 10 14 W. 16 76 i 14 36 A\. ■!■;,-.■ uin.l ,|irr. ll.Mi M.P.H Maximum wind relo. it> M P II Mean precipitation, inches 16 till 2 02 sw 16 <,.-/;.. ■ TABLl II Fog-S 11. Operations in the Region os Cm< igo* Monthly Averages in Hours for 1920 .'.">. Inclusive t J - _ | _>• 1 < 1 ■ g 2 1 = 1 - 11 E < Waukegan 1 [arbor S..iilli < hi. 26 llll 101 ... 75 31 20 21 65 63 :m 14 20 65 95 !H 6 llll 7.-. s 9 58 1117 7(1 13 7:t 1 S8 mi 1 II 59 121 52 1 17 ins 812 113 Hi is 102 171 117 !> 44 145 93 .-.7 II 1,027 I.IS7 7 1 : 70 22 86 ins 71 Michigan ' s 6 1 opposite II" vigution. Smoke . there. Within a stone's throw of almost anj spot one ma.\ find plants of the desert and plants of rich woodlands, plants of the pine woods, and plants of swamps, plants of oak » Is and plants uf the praincs. Species ..f the most diverse natural regions are piled here together in such abundance as to make the region a natural botanical preserve, not only ..f 1 1 •« - plants that are characteristic ..f northern [ndiana, but also • •! the plants ,,f remote outlying regions. Here maj find the prickly pear cactus <>f the thwestern deserl hobnobbing u ltd the bearberrj of 1 In- arctic and alj ■ regions. The com- monest pine <>f 111.- dunes, the jack pine, is far out ..f its main range, reaching here its farthest south. One is almost startled at the number ..f plants of the far north, many ..f » hich, like the jack pine, are not round to tl»- southward <>f mir dunes. S I Mather, ti> \*>rt on tin Proposed Stiwt Dum* Sti'imia! r I 1 • full discussion of the climate of Chicago see the following author titnl f Itnn' 1 Chicago, 191 in an important degree lu the fact thai Lake Michigan exercises an ameliorating influence on the adjacent land. Because of this influence, the region of Chii pecially that part along the lake, docs not suffer from extremes of intense summer deal and winter cold as do parts of the interior of the continent remote fr the lake Frequently during the summer nths the lake regi injoys cool, delightful weather while the count ry away from 1 he dike deal . The summer weal her compares favorably with il resorts. The sweltering 11 excessive de vicinitj of Chicago of the bet er summer rainfall is e Washington, 191* ve public c ample througl I the id J. II. Vrmingt. PIIYSIOORAIMIY OF THK REGION OF CHICAGO region of Chicago, amounting on an average I" over 30 inches per year. From I he standpoint of agricultural re- quirements tliis rainfall is fairly well distributed, al 1(1 inches ordinarily falling during the growing season for crops May. June, and .July. Drought sometimes oc- curs, thereby preventing maximum crop production; but complete crop failure-, such as frequently befall some parts of the country, arc here unknown. Chicago is widely known as the "Windy City," but the winds thus advertised are not more vigorous at Chicago than at other points along the lakes. During spring and summer the winds from the lake are most prevalent, and these l>ritiii in to the land a constant sup- ply of cool, pure air. The dominant winds are from the southwest, the "Prevailing Westerlies," and from the northeast (see wind rose. Kg. 10). The longest periods of sunshine come in the autumn, and Indian summer may he seen at its best in this area. Probably the most distinctive characteristic of the climate of the region of Chicago is its changeableness. This is due to the location of the area in a licit that is traversed by an endless succession of atmospheric dis- turbances — cyclonic storms, or '"lows" they are com- monly called— that sweep across the continent. It is the passage of these storms at intervals of a few days that gives to the weather its changing aspects of heat and cold, rain and snow , sunshine and cloud. These "spells" of weather, whatever their character, are rarely of long duration. It is not generally realized that a climate character- ized by frequent and sudden changes of weather of this sort is healthful and stimulating to a high degree, and is to be regarded as a most desirable asset to a com- munity. Undoubtedly the vigor and activity which stamp the people of this area are in an important meas- ure attributable to climatic conditions. Chapter II THE LAKE PLAIN, \ GREAT INDUSTRIAL \m \ THK Lake Plain (see Pig. 2 includes the low bell of land once covered by the waters of the extinct Lake Chicago. On it are located the sites of Chicago, Gary, Michigan City, Waukegan, Kenosha, Racine, and many oilier cities. Originally a continuous province encircling the lower end of Lake Michigan, this plain has Keen cut away for a 20-mile stretch between Winnetka and Waukegan bythecease less erosion of the waves. Thus separated into two parts, tin- Lake Plain ii"\\ consists of 1 a narrow strip ex tending from Waukegan northward to a poinl 5 miles beyond Racine, and 2 a broad, crescent-shaped tract extending from Winnetka southward around the head of the lake into Michigan. The northern area is 33 miles long and has a maximum width, j 1 1 - 1 north of Racine, of al 3 miles. The southern and much larger area is often referred to as the Chicago Plain because upon this section the city of Chicago is located. Il has a width "i' from Mi to l-*> miles through most of il- course in Illinois, hut narrows rapidly across Indiana, being only about a mile wide where it crosses the Indiana Michigan state line. Although l<> the eye 1 1 • < - Lake Plain appears very flat, it- surface rises imperceptibly from the lake to its contact with the rolling uplands, 1 1 1 < - total ri-<- amount- ing to about (in feet. This remarkable flatness, best shown in tin- vicinity of Chicago, i> the most sinking feature of the Lake Plain. Probably the building of no other large city has Keen attended by such freedom from grading problems as has that of Chicago. This situation, however, has not been an unmitigated blessing, for ii has introduced serious drainage ami sanitation prob- lems. Much of the Lake Plain was formerly swamp ami had to lie drained artificially for habitation. An early ipher wrote. "The country around the extreme south bay of Lake Michigan has the appearance of the sea marshes of Louisiana " the general Hat ness of t he Lake Plain is varied by a feu interruptions, described in the follow ing paragraphs. Sand dunes. In northern Indiana one of the great- est dnne areas known has been developed by action of wind upon sand deposits either left on the plain by Lake Chicago or brought in to the present beach by Lake Michigan. Some of these sand dunes near Michi- gan City are 200 feet high, other dimes less imposing Beverly Hills to Blu of Waukegan. Blm Island Ridg* feat lire on the Lake lillle U; Ridge, From lain in t he vicinity of Chii an isolated ridge 7 miles west ,,f the lake, in the latitude of South Chicago. It is elliptical in form, about 6 miles long, north ami smith, and alioiil I mile wide. Il rises, island like, about -"'ii 80 feet above I he otherwise nearly \Km Fa< tomes Havi tin n Ii. n.i ..-, mi. I'm Land in no CaL! mi I Vn I l ol Imii \\ \ \\n I featureless plain: and al one time it was an island, its summit rising 10 35 feet ab ive the surface of Lake Chicagoat its highest stage. Well borings show that the bed io,k is no higher under Blue Island Ridge than under other parts of the plain. Its existence is apparent- ly due to a thicker deposit oftheglacial drift her. I citj of Blue Island is located at its southern end, Morgan Park is on its crest, and the residential section known as Beverly Mills is near its northern end Stony Island, }ns\ west of South Chicago, is an out- crop of Niagara limestone that rises about 20 feet above the surrounding marshy Lake Plain. Il trends east and west, is | J miles lone;, and '. mile wide. Stony Island is one of the most inl eresl 1 1, | tures ill the region of < Chicago. It is a dome of limestone, the strata of which are steeply inclined, dipping outwaitkvjn all directions. On its sides the grooves and si ratches made bj the overriding glacier may still be seen. Because of 12 PHYSIOGRAPHY OF THE REGION OF CHICAGO these and other similarly interesting features, the Geographic Society of Chicago has urged the preserva- tion lit' Stony Island as a park. Beach ridges and bars constitute important features of the Lake Plain. There arc three main groups of long, low ridges thai traverse the plain, rising in some cases as much as •,'() or .'!() feel above its surface and traceable for many miles. These are the ancient beaches of extinct Lake Chicago. They are approximately 60, 10, and L -'0 feet above the surface of Lake Michigan and record the are parallel to the present shore. On the Chicago Plain they converge toward t lie Chicago outlet, and thus testify to the outward flow of waters at this point during the existence of Lake Chicago. DRAINAGE OF THE LAKE PLAIN The Lake Plain north of Waukegan is drained by short rivers all of which head a few miles hack in the Lake Border Upland. Kenosha and Racine are located at the mouths of two such streams, the Pike and Root three main stages of Lake Chicago. They have been named from towns where their character is well shown: the Glenwood, Calumet, and Tolleston stages, respec- tively. Where the ridges pass through city sites they have in part been obscured by grading or utilized for their gravel; bu1 some of them are still prominent enough to !»• recognized. The ureal Rose Hill Bar that passes southward through Evanston is followed by Ridge Avenue. It has furnished a site for some of the linesi residences in this pari of the city. 1 Outside of the cities, the bars may usually l>c identified by the oak groves thai mark their courses. The glacial map shows the positions of the mosl prominent beach ridges and bars. North of Waukegan and in northern Indiana they \i manj places in the Lake Plain l slight ridges which offered the onlj i Wisconsin Geological and Natural Hi rivers, respectively, the locations being chosen deliber- ately because of the possibilities of harbor development which these rivers offered. Similarly, the location of Mil- waukee was determined by the mouth of the confluent Meuomonce and Milwaukee rivers. Kenosha has never satisfactorily realized this initial prospect, though large sums of money and coul iuual effort have licen expended in an attempt to keep the mouth of Pike River open for navigation. Lake transportation plays practically no part in the present industry of the city. Racine, how- ever, developed a good harbor by deepening the mouth of Koot River. Though for many years this harbor was the leading factor in the industrial life of the community its importance is now greatly diminished. - avenues, it having been necessary in early days tor vehicles to follow Bull. THE LAKE PLAIN, A GREAT IMMSTIUAl. AREA the Lake Plain are the Chicago, Calumet, and Des waterwaj From Lake Michigan to Illinois River, was con- Plaines rivers structed primarily ;^ a drainage canal i" improve the sanitary ..., - . , , ,. ., ,, . condition <>l' the city. B\ ;i reversal <>f the (low in South I he onlv mil nral dramas.' Inn-- mi t he liort hern part , , . ., ,„ . „. , , , , , . , Branch and the mam trunk <>l < hie;!-,, I{|\, r I lie whole stream ol tlic ( hlCagO Plain arc attoriled l,v I lie sluggish , , , , • , , ,• ., . . , ,, . and a large amount of water drawn directh from Lake Michi- Chicago River with it- north and M.utli branches." Orig- „.,„ i,,.,. ,. i,.,i„,t-,, , t,, n„- in,, .11-, lh.' north branch had 1 miles Mississippi river sys- Tin I! i v i K mi i Plow ■■» i in Main Branch 01 i mi Chi. 100 Riven is toward i m Pori cum, m>; Joining witi from Tin \omii Branch, from thi Left, It Li P i tow ah E Right down Tin - lin \s, h \..i i 1 111 Pollution oi rni Plow from the North Branch. wesl of Highland Park, and Bowed southeastward r. By repeated dredgings Chicago River and its branches miles, while the south branch had its source northeast have been enlarged to Form a river harbor. of mi in mil and flowed northeastward through the pres- Before the improvements had begun in l8S3on the present .•ill citj of Chicago, uniting with the north branch a Chicago harbor, there was a bar across tl itlet of Chicago mile from the lake Thee bined streams flowed east Ri ™ ul "' 1 ' shi . fted ""' """'' '"■" ' """ iu i" v ;'."' , . , , , , ,, , , i ,. i- . ■ . position to a point opposite the foot of M 5 I ward lo tin- lake I I11..11-I1 lln- present dounloun district. ' , , , ii , • , ,-, ■ ■»■ present harbor inlet was formed by cutting through this bar I In- original drainage ol t 1 1. - < ili-ago urr and its . ■ ,,.,,, ,, and lo constructing piers i ither side ol the i ul I he north I. rami,,- has been greatly modified by the building of pier has been extended from time to time as the sand accumu the Chicago Drainage (anal. I ; ,i,..| ,„, the north sid< William C. Alden, CI I I 3.1 Ibid., p. 1 1 THE LAKE PLAIN, A GREAT ENDUSTRIAL AREA The Calumet River is a curious and interesting stream which drains the part of the Lake Plain south of Chicago and in northern Indiana. Ii- remarkable his- tory in illustrated in Figure 11. At one time tlii- river entered Lake Michigan near Riverdale. Throughoul the 15-mile stretch between ii- source in Laporte County and Riverdale it flowed parallel to the lake shore and only a tVu mile- from it. Two well-developed parallel beach ridges held il to this very unusual course. I5ut tin- constant wave action kept building up sand bars from the north across the mouth of the river, steadily shifting the mouth southeastward. At times of high water the river would break across the bar obstructing it- ith, but a new liar would again form at the mouth of the river, and the whole process would be repeated. Thus there developed .< -eric- of alternating sand bars and lagoons, the lagoons representing channels former- ly occupied by the river. Eventually the mouth of the Calumet River had shifted eastward a distance of II miles to a point north of Miller. Indiana. Such was the situation when white settlement began. The upper and lower part- of the river then flowed parallel to each other hut in opposite directions, separated by a narrow harrier only 2 or :; mile- wide consisting of alternating -and ridges and lagoons. Frequently the mouth of the river, north of Miller, was nearly closed by -and drift- Mali changed the course of this river, like that of the Chicago River, to suit hi- purposes. The mouth north of Miller was blocked, and an artificial channel wa- dug from the Calumet River near Hegewisch to Lake Michigan at South Chicago. Thi- reversed the How of the lower part of the ( aluinet River, compelling it to How westward like the upper part. The artificial channel at South Chicago was kept dredged, and small -termer- were able to ply between Chicago and Ham- mond. Recently the course of the Calumet River was again altered. The Sag Channel wa- dug from the Calumet River near Riverdale to the Chicago Drainage Canal at Sag. As a consequence, the Calumet River theoret- ically no longer discharges into Lake Michigan hut turn- due westward at Riverdale, crosses the old Con tinental Divide through the Sag Channel, and so passes int.. the drainage of the Mississippi River by way of the Chicago Drainage Canal. The actual condition, however, i- that pari of the lime III,' surface water i- discharged i Lake Michigan. This is because of oc casional II 1- or because of temporarily lowered lake level. The completion of the Burns ditch just east of the Porter-Lake County line allow- the excess (low of the upper reaches of the ( 'aluinet River to discharge direct- ly int.. Lake Michigan east of Gary, at time of flood, hut normally it doe- not affect the current of the stream. Like the branches of the Chicago River, those of the Calumet have low gradients; consequently they are sluggish of current and subject to overflow. Thi- con- dition, together with the absence of any valleys, gives them the appearance of canals, which indeed they prac tically arc a- a re-uli of the maiiv changes they have under-one. Lake Call -t. Wolf Lake, and Lake George the latter now practically aon existent occupy wry -hal- low basins between -and ridges deposited by the shore dnfi of Lake Michigan. The basins of these lakes prob- ably re-ul ted from I he da mini u- of a former hay at this point. Lake Calumet, the largest of the lakes, ha- an area of ahoul .'! square miles. A channel links Calumet and Wolf lakes with Calumet River. It ha- been pro- posed that Lake Calumet be deepened ami converted int., a harbor. Chapter III THE LAKE BORDER UPLAND, A RESIDENTIAL AND RECREATIONAL AREA WEST of the Lake Plain lie the Lake Border Upland, the Valparaiso Upland, and the Oiilcr Upland, each consisting of a series of terminal moraines successively deposited mainly by the Lake Michigan lobe of the Wisconsin glacier. These three provinces are distinct from one another in t lie central part of the region of Chicago, but when traced northward they merge into a continuous upland (see Fig. 2). The Lake Border Upland is an elongated province five to fifteen miles wide whose main body extends from the cities of Des Plaines and Winnetka northward beyond the limit of the region of Chicago and has a hint;. Hat extension to the south reaching as far as Oak Park. From Winnetka to Waukegan the province is bounded on the east by conspicuous lake Muffs, LOO feet high in places, that rise abruptly from the present shore of Lake Michigan. Hence I he name Lake Border Upland. North of Waukegan these bluffs are alisent and a narrow strip of the Lake Plain separates the up- land from Lake Michigan. Three-fourths of the western margin of the province lies along the valley of the Des Plaines River and that of its tributary, Mill Creek. The surface of the Lake Border Upland varies from (10 to over 200 feet above Lake Michigan. Its topog- raphy is characterized by a scries of parallel north-south ridges, terminal moraines, separated by narrow strips of ground moraine (see glacial map). The alternation of these ridges ami Hats produces a gently rolling surface that contributes greatly lo the scenic charm of this region. Though usually very distinct, the ridges at places coalesce or divide so thai the total number is not everywhere I he same. Usually three may he recognized in Illinois and four in Wisconsin. The ridges vary great- ly in width and height, those farthest from the lake being the wider and higher. The crests of t he ridges rise and fall In low swells, and the western slopes are usually narrower and consequently sleeper than the eastern. The ridge next the lake is fron • to four lake level and 35 to (1(1 feel above the valley wesl of it. The southern end of this ridge, at Winnetka. has been .ut off by the lake. Il has apparently had its entire east -lope and a portion iif the crest removed by the lake, there being a descent im- mediately In,.,, the I, luff on the lake lo the slough, which lies west of Hie ridge. Following the ridge north lo Highland Park I In- crest ami east slope appear. 1 A series of sleep ravines, most of which are less than a mile long, extend hack into Hie moraine between Winnetka and Waukegan. Until recently bluff and ravines were in a state of active erosion, hut this condi- tion has been largely stopped by landowners who have developed fine home grounds along the shore. A moraine in northern Indiana which belongs In this upland extends from a point near Dune Park eastward and northeastward into Michigan. The city of Chester- ton lies just south of its western end, and Michigan City lies between it and the lake. Although its average width is scarcely a mile and it is inconspicuous through much of il s course, it divides the drainage district of I he Calu- met River from that of Trail Creek and causes the two streams to flow parallel to the shore of Lake Michigan for some miles (see drainage map). The streams of the Lake Border Upland lie in the troughs between the ridges, and thus parallel one another except at points where they turn at right angles and flow through gaps they have cut in the moraines. This province is drained chiefly by the headwaters of Hie Root, Pike, and Des Plaine, rivers, and by Hie north branch of the Chicago River. The glacier left drainage conditions very much dis- turbed, and not nearly all of the many depressions oc- curring on Hie Lake' Border Upland have yel been drained, either naturally or artificially. Consequently (here are a lew lakes and ponds and great areas of marsh occupying elongated tracts between the moraines. One of the most typical and extensive of these is a marsh known as the Skokie. which lies about \\ miles west of the lake shore between Winnetka and Highland Park. -,/ Sliilc.i <;,nl„i,in,l . THE LAKE BORDER UPLAND 1 BJ s '" "" upland IV Winnetka to Waukegan. Residential towns are al- Mucli of the upland is a rich farm-and-dairy coun- si continuous to the Wisconsin line, and thousands i ry. In recenl years it has become a Favorite residential of Chicago con ters, served by the electric and -I cm in ad recreational section Vreas have been set aside by railroads, now nave their homes in such residential he Foresl Preserve Commissioners of Cook and ad- towns as Winnetka, Glencoe, Highland Park, High- icenl counties for the preservation of the growth of wood, Fori Sheridan, Lake Forest, Lake Bluff, North ative trees which is exceptionally rich over the upland, Chicago, and Waukegan, most of which municipalities ml which was being rapidly destroye I until the Foresl are 6 100 feel higher than the Lake Plain al Chicago. reserve districts began their acquisiti f land. The Picturesque bluffs, trenched by ravines, and the high isl few years have witnessed a remarkable developmenl rolling upland with its wealth of trees make this section Chapter IV THE CHICAGO OUTLET, THE GREAT PASS TO THE MISSISSIPPI VALLEY TIIK Chicago outlet (see Fig. 2) leaves the Lake Plain by two branches, separated by the tri- angular-shaped elevation known as Mount For- est Island. These branches unite at Sag into a single valley which cuts southwestward, bisecting into north and south parts the Valparaiso Upland, the Manteno Plain, the Morris Basin, and the Outer Up- land. The cities of Joliet and Morris are located in the outlet. The branch of the outlet that lies south of Mount Foresl Island is known as the Sat;, and is smaller than the other branch. At one stage during which the Sag carried water from bake Chicago, it was itself divided at its eastern end by bane's Island, an elevation on which the village of Worth is now located. The main channel of the outlet lies to the north of Mount Forest Island. From Summit to Joliet it is a steep-sided, flat-bottomed valley, from \ to \\ miles wide, and 20 70feet deep, [n places the limestone bluffs are vertical or overhanging. Along most of this stretch the glacial drift is stripped away and the outlet is cut down to the lied rock or even into it. Helow Joliet the outlet loses its valley character as il widens into the flat Morris basin. In this lower stretch, which is as much as .5 miles in width, the removal of glacial material was less complete, and little erosion of bed rock took place. In I he Morris Basin the northern margin of the outlet is marked by the prominent bluff now followed by another "Ridge road" (now Stale Highway No. ?), hut its southern margin is ill defined and must l>e arbitrarily draw ii. Where the Chicago outlet leaves the bake Plain near Summit it is only IS feet above the level of bake Michigan. Between the divide at Summit and the town of bemonl the slope is so slight that this stretch is known as the "12-mile level." From Lemonl south- westward, however, the descent is more abrupt, there being a 90-fool drop in the 25 miles between Lemonl and the head of the Illinois River, thus bringing the bottom of the outlet aboul 7:> feel below the level of bake Michigan. Most of this fall occurs in tin- "rapids sect ion" of less I han ten miles between Romeo and Joliet . Illinois Geological Survey, Hull. 11. p. \. ' Ibid., p. 56. The Outlet River found the preglacial valley which it adopted partly tilled with outwasb gravels deposited during the retreat of the ice. This gravel filling it largely cut away, hut remnants persist as terraces extending along the border of the valley from Romeo southward. In the upper part of the valley some of the crests of these terraces are as much as 100 feet above the river, hut in the lower part their elevation is about half as great, between Joliet and the head of the Illinois occur several island-like mounds, remnants of this former filling. The Chicago outlet is now occupied by the lower part of the Des Plaines River and the upper part of the Illinois River. It is also traversed by two canals: the Illinois-Michigan Canal and the Chicago Drainage Canal. Tributary to the latter is the Calumet-Sag Channel, so called because it connects the Calumet River with the main drainage canal through the Sag branch of the outlet. DES PLAINES RIVER "The Des Plaines issues from a flat swamp or slough near the boundary of Racine and Kenosha Counties. Wisconsin, where drainage is so imperfect that in wet weather part of the marsh discharges northward to Root River." 1 From its head it trends southward be- tween two moraines of the bake border Upland and drains a long, narrow basin 90 miles long and rarely more than 1.5 miles wide. Its most important tributaries are Salt Creek and On Page River, both of which flow parallel to each other and to the Des Plaines itself for a long distance. North .if Maywood (he Des Plaines River emerges upon the bake Plain. "Extending its mouth out on the flat plain south of Riverside .... the Des Plaines seems to have had a free choice between a course to the Mississippi or to the St. Lawrence." 2 "So flat is the plain at this point," remarks (iold- Ihwait, "that the escape of the Des Plaines from t he lake plain westward through the deep notch in the moraine seems highly accidental." 1 In fact, a well defined slough, formerly known as .Mud Lake, leads eastward to the south branch »>t' the greal river whose volume was perhaps comparable to that of the St. Clair River today was left the little IV- Plaines, a stranger in the district, which straggled into the greal valley as if by accident." 5 Al Romeo the river reaches the upper end of a -eric- of rapids which lower il 80 feel in I In- in miles be- tween this point and "Lake Joliet." Through the wesl side of Joliet the river is artificially confined, bul im- mediately below the city, al Brandon's Bridge, il ex- pands to till Lake Joliet, a depression probably formed by the Outlel River at the poinl where it crossed from the resistant Niagara limestone t<> the softer and more easilj eroded Richmond formation. Lake Joliel is ■"> miles long, about in feel deep, and lies 75 feel below Lake Michigan. At Channal the Des Plaines is joined by the Du Page, and immediately below their junction there occurs another expansion, "Lake Du Page." Haifa mile farther downstream il joins the Kankakee The poinl of confluence of these rivers is taken a- the head of the Illinois River. ILLINOIS l!l\ i R The Hlinois i- the master-stream of the region of Chicago, receiving the water- of all of the important rivers with the exception of the few that dram east- ward ml" Lake Michigan. It is commonly divided into two sections, the upper Hlinois and the lower Dlinois, the poinl of division being the greal bend near Henne- pin, where the river abruptly turn- southward. The two sections are radically different. Tin- upper Dlinois, 63 miles in length, has a steep gradient, flows largely over bed rock, and excepl in the Hal Morris Basin occupies a valley thai has steep rock bluffs averaging 1 \ miles apart. Thisisa postglacial course along which the river i- -till busily excavating a channel. The lower llliniii-. about 200 miles long, has a very low gradient, i- ii< il excavating in bed rock, and wander- aimlessly ,.. 81. / ■ ■ . p. 56. over a flood plain 2 •"> miles wide a preglacial course much older than the course of the upper Illinois. Only a 20-mile stretch al the head of the Illinois lies in the region of Chicago, but according to L. K. ( looley, of the Drainage and Water Supply < 'ommission cit' Chicago (the organization which preceded the Sani tary District of Chicago . it- major tributaries have part or all of their drainage basins in the region of Chi- cago, and these contribute over a third of the total Loi k- i\ mi. < 'in. \,..i Dbaixage Canal, New i Pari oi mi In inois W The drainage basins of these tributarii lowing area-: - have fol Des Plaines River including the l>u Page River, 326 sq. mi. I 393 Kankakee River 5,146 Aux Sable Creek 218 Mazon Creek 540 Fox River I ?00 Total 9,996 Owing l" a reversal "t' flow through the canal- of the Sanitary District of Chicago, all of the drainage from the Chicago River watershed of 226 square miles i- tributary t<> the Illinois River, A portion of the run- off up t" 2,400 en. ft. per second in storms bul ordi- narily 700 cu. ft. per second from the Calumel water- shed of 690 square miles also reaches the Illinois. Despite the general narrowness of the upper Illinois Valley si "I its course across the region ■>) Chicago i- broad and Hal \t it- head, tin Ilileiiee of the Kankakee and I )e- I'laine- rivers, ale n-e- a -leep bluff 120 feel high on the north side known as Dresden I - a 40 PHYSIOGRAPHY OF THE REGION OF CHICAGO Heights: this is moraine, a sectioi lie (I: CANALS The Illinois-MichigaD Canal, built and 1848, extends from the south brancb River southwestward through the outle the Minooka etween 1886 F the ( Jhicago a distance of The Chicago Drainage Canal was made to meet the needs of the growing city of Chicago, as a means of sewage disposal. This dual-purpose sanitary and ship canal reversing the flow of the sewage-laden Chicago River into the Illinois watershed, begun in 1892 and completed in 1900. was excavated through the Chicago outlet between the old canal and the Des Plaines River. - nearly LOOjmiles, entering the Illinois River al La Salle. Originally it'was 6 feel deep, 60 feel wideal the surface, and .'iiij'cd wide al the bottom in earth, and ts feel wide in rock. Al the divide its summil level was 8 feel above the low water level of Lake Michigan, and al its termination it was 150 feel lower. Four locks, two al Lockporl and two at Joliet, were necessitated by the and where in rock, 160 feet. 1 steep gradient along this section. In time this .anal fell The declivity is I foot in 10.0(1(1 feel In the Section a into disuse largely as a result of railroad competition, Willow Springs, and 1 fool in -JO. 000 feet below, g and now along nine], of its length it is little more Mian : al fall from the head of Robey Street to the a ditch. trolling works al Lockport of about .">', feet. i Illinois Geological Survey, Bull. 11, p 8. Its length From the west Fork of the Chicago river at Robey Street to the controlling works at Lockport was twenty eight miles. Of this a little more than half (the fifteen miles between Willow Springs and Lockport) was cut through rock, \lm\e Willow Springs the channel was sunk wholly in unconsolidated beds, mainly glacial drift. The depth of the canal is -'t Feet, it- bott width, when' in earth. 202 feet, THE ( IIK A(.<) OUTLET The Calumet-Sag Channel, a feeder for the fore- going, was "Iult along the line of the old feeder for the Illinois-Michigan Canal. It was begun in 1911, com- pleted in 1922, inn! i a i i'ik I - IV the Calumet River near Riverdale through the Sag Valley to the main drainage GEOGRAPHK SIGNIFICANCE OF TH1 CHICAGO OUTLET Through this channel, carved thousands of years ago by a river now extinct, there passes a full and ceaseless stream of human activity. Providing as it does a nat- ural r- ■ 1 1 1 1 < ■ connecting the Greal Lakes region with the Mississippi Valley, this valley is one of the greatest natural passes in our country. Our more admirably adapted for man's purposes could hardly have been designed by man himself. It- industrial significance lie- in the fact that the < "mil inental Divide along tin- valley is onlj 15 feel above the surface of Lake Michigan, whereas the nexl lowest point on the divide is al Fori Wayne, In, liana, and is fully 190 feet above the lake. "No wonder that the idea of an artificial channel near / f.. p. i Chicago, to join the lakes with the Mississippi, was con- ceived by Louis Joliet, ■ of the first [white] men to cross the divide." 1 Long a favorite mute with the Indians and early explorers, the outlet came to a fuller utilization with the settlement of the interior and the growth of Chicago. The Illinois-Michigan Canal, the Chicago Drainage Canal, the Chicago and Alton Rail- road, the Atchison, Topeka & Santa IV Railroad, and an arterial highway all chose a route southwestward from Chicago through the nutlet. The railroads and highway I li n- avoid the grades otherwise necessitated in passing over the Valparaiso Upland. Where the nut- let widens below Juliet . other highways and railroads pas- through or across it. Along the outlet cities have -row ii up that are largely dependent on these hue- of transportation. Despite this great development it is obvious that the fullest utilization of the < !hicag itlel is -till far from being realized. Plans are under waj for a navigable waterway which will enable barges to pass from Lake Michigan to the Mississippi River. Chapter V THE VALPARAISO UPLAND, A CONTINENTAL DIVIDE THE Valparaiso Upland is a broad, elevated bell of land which, to borrow the descriptive figure employed by Dr. T. ('. Chamberlin almost a half-century ago, "may belikened toan immense U. embracing the great lake between its arms" (see Fig. L 2). It is designated by the name Valparaiso after the city of Valparaiso, Indiana, located on a prominent part of ii, and because geologists have long applied this name to the moraine which forms its greater bulk. The Wisconsin section of the upland includes part of the moraines deposited by the small Delavan lobe and a very small part of those deposited by the Green Bay lobe (see Fig. 8), but the greater part, that trending through Illinois and Indiana, was deposited by the Lake Michigan lobe, and is the most prominent of the moraines attributed to this lobe. On its lakeward side this province is bordered by the Lake Border Upland, except in the middle where it is in direct contact with the Lake Plain. On its outer margin it is hounded (1) by the Morris-Kankakee Basin from near the Illinois-Indiana line east; (2) by the Manteno Plain from the state line northwestward to the vicinity of Elgin; and (3) by the Outer Upland from Elgin north- westward into Wisconsin. South of Elgin its outer mar- gin is fairly distinct because of its contact with two lowlands; but north of Elgin the boundary between the two uplands must be somewhat arbitrarily drawn, as in the case of the Valparaiso Upland Lake Border Upland contact. West of Chicago the Valparaiso Upland is crossed by the Chicago outlet and literally cut in two. Mount Forest Island, which is isolated by the branches of the outlet, is pari of the upland; and at this point the east- ern margin of the upland is farthest from Lake Michi- gan, being 13 miles away in a line directly through Chicago. The upland is widest in the northern portion. being 25 miles in width through the middle of Walworth County. Southward in Illinois it narrows to the Chi- cago outlet: and throughout the 80-mile course from the outlet southeastward to Valparaiso it has a uniform width of from 12 to 1.*) miles. At Valparaiso it narrows abruptly to less than half this width, and north of Laporte, Indiana, it is only 4 miles across. The relief of this province is great, amounting to ' Handbook of Indiana Geology, |>. 1 1 i. fully 4.50 feet. In general, the outer margin is higher than the inner, although this relation is reversed east of Valparaiso. The northern portion is much the highest. most of it being over 800 feet above tide, two points in northwestern Cook County and large areas in McIIenry County being over 900 feet. In Walworth County, Wis- consin, is found the highest point in the region of Chi- cago, a hill ."> miles north of Williams Bay that reaches an elevation of 1,140 feet above sea-level, about 560 Feel above Lake Michigan. The middle portion of the up- land is fairly uniform in height, its crest varying from 700 to 750 feet above tide and reaching S00 feet only in eastern Will County, at the village of Monee on the Illinois Central Railroad. The narrow portion east of Valparaiso is notably higher, its crest reaching an alti- tude of 885 feet above tide in Laporte County. 1 Like the other two uplands this province is a sysl em of narrow, more or less parallel ridges separated In- lower tracts. On the glacial map (sec Plate Ii the differ- entiation of the upland into its moraines and inter- morainal tracts has been indicated as fully as geologists have carried this analysis to date. In areas where such detailed study has not yet been made, the moraines have been mapped as "undifferentiated Valparaiso." Eventually, with the progress of detailed mapping, it will be possible to locate and name all of the small moraines. As compared with the adjacent Lake Border Up- land, the Valparaiso Upland exhibits, on the whole, a surface of far more diversity. This is because the mo- raines which it bears show a wide variety of outline, ar- rangement, and contour, being usually less symmetrical and regular than those on the Lake Border Upland. The northern portion is exceptionally rugged and irregular, and exhibits better than any other part of the region of Chicago that peculiarity of morainal deposits, "knob and kettle topography," a surface characterized by rounded hills and intermediate undrained depres- sions. These depressions are of great interest and have originated in several different ways: through (1) the damming of stream valleys; (2) the irregular piling up of glacial drift l>y the ice, giving rise to hills and de- pressions; and (.'!) the melting of isolated blocks of ice that had been surrounded or buried by glacial deposits. THE VALPARAISO I I'LAM) Many of these depressions are now occupied by lakes and marshes and others were For rly so occupied, hav- ing been filled or drained. This is pre-eminently the lake region of Illinois and southern Wisconsin, the total number of lakes in Walworth, Racine, Kenosha, Mc- Henry, and Lake counties running into the dozens. In southeastern Wisconsin from 12 t<> 15 per cenl of the land area is revered with lakes, marshes, or land for- merly covered « iili lakes and marshes.' Among the bet- ter-know n lakes are the Oconomowoc lakes, Lake Dela- van, Lake ('(iino. Lake Geneva, Wind Lake, Lake Eliza- beth, and Silver Lake iii Wisconsin; and Lake Marie, Grays Lake. Fox Lake, Pistakee Lake, Lou- Lake, and Lake Zurich in Olinois. Of these Lake Geneva is the largest, having a length of 8 miles, a maximum width of 2 miles, and a depth of I 12 feel Mosl of the other lakes are [ess than IS feel in depth. All of them having become or an- becoming busy summer resorts, and many permanent, year-round residences are being limit on their shores. A> the glacial map indicate-, the morainal ridges north of the Wisconsin line are peculiarly arranged in two sets: I I those in the eastern part of the upland. trending north and south; (2 a group of curving mo- raines that branch off southwestward from the first sel and almost at right angles to them. Their courses form a marked eontra-t with the prevailing trend. These moraines are those of the -mall Delavan lobe that ton, icd between the Lake Michigan lobe and the Green Hay lobe (see Fig. 8 probably in response to a pre- existing lowland at this point. Thrown across pre- glacial valleys, they constituted dams which produced Lakes Geneva, Delavan. and Como, the Bnesl in south- eastem Wisconsin. In northern Illinois the moraines form a composite mass, or "moramal complex." extremely difficult to analyze; nevertheless. ;, pronounced north-south tend- ency may Le recognized in the arrangement of the ridges. In the middle portion of the Valparaiso Upland the topography is far more subdued than in the northern, being gently rolling in character. Locally, as at West Chicago, the "knob and kettle" topography does occur. Inil for the most pari the knolls ami depressions are not prominent. The morainal ridges arc generally low and not infrequently HI defined. Swamps and ponds arc common bul lakes are rare (>,, Mounl Foresl Island the surface is vei the knolis ami hollows having a range of over 50 feci. Ponds an- abundant. Much of this area is now in the Cook County Foresl Preserve of Palos Park, and the features are th lis preserved in their natural state. From the Indiana-Illinois line eastward to Valparaiso three ll ' ;".i/ and Xalural II Bull. 58, p. Hi. crests an- recognizable, I he mosl southerly of these being weaker than the other two and disappearing entirely at Valparaiso. Five miles southeast of Crown Point is ( 'edar Lake, over a square mile in area, I he only lake of any consequence in this part of the upland. Near Valparaiso the elevation increases ami there is a corresj ling increase in ruggedness. A striking fea- ture of this interesting portion is the fact that the cresl of the upland is near the northern edge; the northern -lope ,s abrupt, there being a rise of [50 f.-ct in the 2 miles from the Lake Plain, while the southern slope is broad ami gentle (see Fig. 3 , Another peculiarity is Chicago A Cktstai Lake, III., a Typical Lake Basin in thi R 1 hi. ii. i. Si mini mil ii in i'i km \ Vgrii i i.n km. Land. that from Valparaiso eastward the moraine is composed largely of sand and -ravel instead of the typical "bowl- der clay" characteristic of moraines There are promi- nent knolls in this part of the upland, and in the liasins between them are inclosed shallow lakes. This is the western pari of the lake region ol [ndiana Hudson Lake in northeastern Laporte C« ty and Pine Lake north- vvesl of the city of Laporte arc the larger of the lakes in this region. DRAIN vol in nil v vi.rvii vis,, i i'i vmi Thai section of the Valparaiso Upland north of the 1 -it let is drained southward by the Des Plaines and the Fox rivers South of the outlet the upland forms the Continental Divide, drainage to the north entering Lake Michigan. Tin' diversion of tin- Calumet River through the Sau Channel hit onlj an insignificant amount draining into th,. lake, that earned l.v Galen and Trail creeks in the vicinity of Michigan City; bul the new Burns ditch helps restore the natural drainage of the area -ir Fig I I \\ iter from the north by the Fox and th.' Des Plaines and much of that fr he south and cast l,y Hie ( alillncl and Kankakee is eventll- ■ 111,,,,, I ^24 •HYSKKiRAI'HV OF THE REGION OF CHICAGO ally received by (lie Illim southward to I lie Mississi d westward and GEOGHAPHU I I i/TURES OF TH] VALPARAISO T I'l.WI) Like the Lake Border Upland, the Valparaiso Up- land i- .in exceedingly rich farm-and-dairy region. The northern lake section U a part of I he famous dairy sec- tion that has placed Wisconsin foremost among the dairy states of the country. The Indiana part is hardly less important as regards dairying, Lake County being known as "the Denmark of Indiana." The production of stock and grain is important in all parts of the province, especially in the middle, or Illinois, portion. Being primarily an agricultural region, this province has a great predominance of -.mail country towns, the larger ones being established along the major streams or along the margin of the Lake Plain. In most eases the communities in this upland are located on the crests or sides of moraines (see glacial map, Plate I). Approaching the city of Chicago one finds that vil- lages become increasingly numerous. These are served by a close net of railroad lines that converge on Chicago and offer excellent passenger and freight transporta- tion. Many of the towns. Wheaton and Downers (J rove for example, even though located some distance out on the upland, contain a large percentage of people who have their occupation in Chicago. Other communities are built on the edge of the rolling upland bordering the Lake Plain, thus combining the advantages of accessi- bility to the large city with those of suburban location. Glenview, Park Ridge. Franklin Park. La Grange, Palos Park, Ilomewood. and Chicago Heights are in this group. This chain of marginal towns on the more habitable upland is rapidly becoming continuous. On the uplands railroad line-- arc not quite so direct as in most parts of the region, their courses being de- termined by the uneven topography. Highways, also, find it impossible to follow section line- so faithfully as they do on the more level parts of the region. Streets may. and usually do. depart from the gridiron pattern to follow the topography SO as to give home sites the benefit of elevations. Thus drainage is usually easily ob- tained for storm and sanitary sewerage. On I he uplands, also, are found the best sites for forest preserves and parks, country clubs, golf courses, and riding clubs. Large areas, particularly near the more congested part of the region, have already been acquired by private capital and by public funds for these purposes. By the middle of 1926 the Cook County Forest Preserve Com- missioners had acquired .'51.000 acres of forest-preserve lands, approaching the first objective of 35,000 acres. In Du Page County over 1, L 200 acres had been taken over for forest preserves, and Kane County is just em- barking on its program of acquisition of forest prescrx es. These areas are being selected very wisely so as to in- clude all the natural features of the region and hence all types of flora and fauna: they include upland forests and prairies. Hood plains, ravines, swamps, rivers, ponds, lakes, and springs, with a corresponding variety of vegetation. Mention should also be made or the great many summer resorts in the lake region. So numerous are these resorts, and SO highly coveted are choice locations in them, that in certain instances desirable home sites on the lakes command prices higher than those in the better residential sections of Chicago. Many of the summer resorts have become perma- nent villages, and are made up of beautiful, substantial homes. The rounded and usually wooded knolls of the lake country and the clear blue lakes they inclose con- stitute what is undoubtedly one of the most pictur- esque parts of the interior plain. Possibilities for further utilization of this beautiful province for recreational purposes are practically un- limited. Chapter VI THE MANTENO PLAIN TIIK Mai.tr,,,, Plain takes its name' from the town of Manteno, Qlinois, located al a poinl where this province is widesl and where it is typically developed. It is a crescent-shaped tract ■ ■ Fig 2 lying wholly wesl of the <>1<1 Continental Divide: il > inner margin faces northeast and faithfully parallels the shore of Lake Michigan. It - widesl and most southerly part i- north of Kankakee, whence it pinches oul both t<> the north, where it end- in a sharp poinl south of Elgin, and to the easl where it crosses the Illinois-Indiana state line and end- in a blunt point near Lowell. The length of the plain, along it- midline, i- 80 miles; it- average width is 12 miles; and it- maxi- mum width i- 17 miles, jusl north of Kankakee. i), i the inside the crescenl i- bounded by the outer front of the Valparaiso Upland. On the outside it is bounded from Elgin southward t<> the Chicago outlet by the Minooka moraine, a part of the Outer Upland; from the outlet to its eastern tip it is set off from the Morris- Kankakee Basin by the Mull- of the Kankakee Mixer. The Chicago outlet crosses the plain at Joliet and divides it into north and south portions, the latter being the larger of the two. In its course across the Manteno Plain the < IhicagO outlet i- at lir-l deep and narrow, lint below Joliet it becomes broad and -hallow and widens into the low Morris Kankakee l?a-ill. The surface of the plain descends from 7.">o feet above sea-level south of Elgin end. Easl of Wilmington, wh< crosses, the border of the plain 650 feet al ll ,e eastern • the Wabash Railway . low e-t . will. an eleva- In the nort hern port ion t he -lope i- sides, giving rise to a basin about 866 irea and drained by the -outhward- River. In the southern portion the ti f Mill feet inward from hot I square mile- in Bowing Du Pag< slope i- generally southwestward from the Valparaiso Upland toward t he Kankakee River. ( Consequently, t he streams which are tributary to the Kankakee River have approximately parallel courses and bring out strikingly the -lope of tin- portion of the Manteno Plain. The plain character of this province i- varied by the presence of two moraine- that repre-ent brief pauses of the iee front a- it retreated aero-- thi- area. They are the Rockdale 5 and Hie Manhattan moraine- see glacial map . both characterized by gentle -well- and -hallow. undrained depressions. Three large abandoned valleys, now sloughs, cross the Rockdale moraine in a general east-west direction north of Joliet. During the period of glacial retreat they were occupied by g l--i/ed river-. In the extreme southern part, near Kankakee, the Rockdale moraine and the Surface Of the plan, are crossed by -hallow channel- which were formed by the torrential glacial waters escaping through the Kankakee Valley while the great ice lobe -till occupied the Lake Michigan Basin and Plain. Name pro| ■■! bj l>r. M. M. Leigh to / ■ Geological Survey, Hull. Chapter VII THE MORRIS-KANKAKEE BASIN, A POTENTIAL RECREATIONAL BELT M "OST extensive of the lowlands in the region of Chicago is the Morris-Kankakee Basin, a broad belt across the entire southern part of the region (see Fig. 2). A compound province as is suggested by its name, it consists of (1 ) the Morris Basin, a flat, saucer-shaped depression at the west end: and (2) the Kankakee Basin, the broad valley of the Kankakee River that enters the Morris Basin from the east. Because there is no physiographic break between the two basins, and because they have many features in common, they are here regarded as one province. On all sides this basin is bounded by higher land: on the northwest, west, and south by the Outer Upland; and on the north by the Manteno Plain and the Valparaiso Upland. Near its western end it, too, is crossed by the Chicago outlet. It is from fifteen to twenty-five miles wide through most of its course, but near Kankakee it is constricted to a width of 4 miles. In general the basin slopes from east to west, the wot ward flow of the Kankakee River expressing this slope. The higher elevations, about 7,50 feet above tide, arc in eastern Indiana; and the lowest part, an eleva- tion of .3.50 feet, is the center of the Morris Basin. The descent from the sides of the basin toward the river is in place- imperceptible. Till: MORRIS BASIN Were it not for the gap in the western edge (outside the region of Chicago) through which the Illinois River flows, this basin would contain a large lake, as it un- doubtedly did at the time of glacial retreat. Much of its surface is lower than the surface of Lake Michigan, as b show n on the relief map (Plate II). Because the Mor- ris Basin is a saucer-shaped depression, the drainage has a radial pattern, (hat is. the streams flow inward toward the center of the basin. THE KANKAKEE SAM) PLAIN In Indiana the entire breadth of the Morris-Kan- kakee Basin is a plain covered with sand or very sandy soil, and is therefore frequently called the "sand plain." This great expanse of sand represents the deposits made 1 United States- Geological Survey, Monog. 88, p. 506. J Ha during the glacial period chiefly as outwash from nearby ice lobes. Throughout most of its course this province is a monotonous lowland without any interruptions other than the numerous sand dunes and occasional shallow- bars that rise from its surface. In parts of Indiana sand ridges, probably built up by the wind, are fairly con- spicuous. In the Morris-Basin a prominent gravel ridge forms the northern margin of the Chicago outlet: and south of the outlet clearly marked shore lines record the levels of the lake that once occupied the basin. The master-stream of the Morris-Kankakee Basin is the Kankakee River. Though it receives many tribu- taries, all, except the Iroquois River, are relatively small. In the Morris Basin the largest streams are the multibranched Aux Sable and Mazon creeks. Originally most of the sand plain and parts of the bordering areas were in a swampy condition. Old set- tlers recall that areas were under water so deep that it was necessary to swim horses across. In 18!)!) Leveret t wrote of this lowland: The Kankakee marsh embraces probably 1,000 square miles or about one-fifth of the watershed. In addition to this. about 3,000 square miles have very poor drainage The head of the Kankakee marsh near South Bend, Indiana, stands about 140 feet above Lake Michigan, or 720 feet above title. From this point to Momence, Illinois, a distance of 8'2 miles by direct line, there is a continuous marsh. The amount of water above the junction with Yellow River is insufficient to from a well-defined channel, but below that point there is quite a definite open channel. The small tributaries are usually lost in the marsh before reaching the main stream. The Kankakee Valley Drainage Company has estimated that 625 square mill's may lie direct ly reclaimed ami 1 ,000 square miles benefited by systematic ditching. 1 In the 100 miles through which the Kankakee River flows in Indiana it originally meandered so that its length was .'500 miles and its average fall 4 inches per mile. 2 During the last twenty years conditions in the marsh bell have been changed greatly. The Kankakee and many of its tributaries nave been straight cued and deepened so as to increase both their gradient and ndbooh of Indiana Geology, p. ~2. THE MORRIS KANKAKEE BASIN capacity. Much drowned land -till remains, however, all the way From Kankakee County eastward t<> Starke and Laporte counties, especially close I" the Kankakee Hi\ <-r. Even where ditching has been resorted t<>. main- tenance of i:<""| drainage presents a difficult problem because at times of high water the streams and ditches bring in water beyond the capacity of the Kankakeee Channel. These floods have had importanl bearing on town locations. Morris, for example, is located on a terrace well beyond the reach of the overflows thai fre- quently iH-ciir in the Morris Basin, and there are pract ically no communities of any size on the Kankakee easl of Momence. Where the sandy soil of the lowland is drained it is usually suitable I'm- farming, corn and hay being com- monly grown "ii it. From marsh area- not yel drained, "wild hay" i- often cut. A -tri|> of practically un- changed lowland in places several miles wide extends fr Kankakee County eastward along the Kankakee. Much of il i- -lill in Forest, the native growth of trees including maple, ash, elm, birch, and oak. In open glades cat-tails and rushes grow luxuriantly farmers own wood l<>t- in this area and during the winter go into tin- woods on ili<- ice to cul and haul out an annual supply of firewood. 1 On dry sections hunting and fishing camps have been located Attempts have been made to reclaim parts of this undrained belt, bul the returns have nol justified the high expense. For this reason the area should prove ideal for t'i>r<--i preserve and should !»• maintained in il- wild state, so thai the plant, bird, and animal life -lill abundant there may be cared for. The area i- adapted by nature for ilii- type of recreational use and is of little value for any other purpose. / i - I >ep1 . of Agriculture . p. \ J. Chapter VIII THE OUTER UPLAND, AN AGRICULTURAL AREA THIS province is the third and outermost of the three concentric uplands thai occur in the area. Like the others it encircles the lower end of Lake Michigan and trends parallel with the shore of the lake (see Fig. 2). Only extensions from its inner margin come within the region of Chicago, the main part of the upland lying outside of it. Here is the front along which the edge of the ice stood stationary for a long time in the course of its northward retreat. Though not so pronounced as the Valparaiso, this upland is very prominent through much of its course. It will be considered under three sections; ( 1 ) a northern portion, extending in a broad belt from the Wisconsin line south- ward to the north end of the Morris-Kankakee Basin; (2) a middle portion, extending from the .southwest corner of the region of Chicago eastward nearly to the Indiana line; and (3) an eastern portion, in Indiana, occupying the southeast corner of the region of Chicago. The northern portion, like the Valparaiso Upland, has an unusually great relief for the region of Chicago, its altitudes ranging from little more than 600 feet above t ide at the southern end to altitudes of 1,000 and 1,050 feet in the northern portion west of Elgin and at the Wisconsin-Illinois state line. The northern half, north of the town of Elburn, is distinctly higher than the southern, most of it being more than 800 feet above sea- level and large tracts being over !)<><) feet. The surface of this highland shows well-marked terminal moraines. Two of these, the Minooka and Marengo moraines (see Plate I), trend north and south and arc very long. The Minooka moraine extends south lo the Chicago outlet, 16 miles beyond the main part of the upland, thus forming the eastern rim of the Morris Basin. The Illinois River has cut into the south- ern tip of this moraine and developed a sharp bluff 120 feel high, called Dresden Heights. Here the Minooka moraine is fairly conspicuous, but in general it is not prominent, being characterized by Leveret I as '"a single smooth ridge on whose crests and slopes there arc few swells exceeding lit feet in height."' The other moraine, the Marengo.' lies to the west of the Minooka and extends from a point 5 miles west of Batavia northward beyond the Wisconsin line. This 1 United States Geological Survey, Mmm,/. 18, p. 819. is a high, broad, and rugged moraine whose crest reaches almost 1.100 feet above tide in northwestern Kane County. From its southern end to the town of Hamp- shire, a distance of IS miles, it is prairie like, presenting a scries of billows 40 or .50 feet high and 1,000 to 1/200 feet across. From Hampshire northward its contours are sharper, and it has characteristic "knob and kettle" topography. At its eastern border it rises ?.". 12(1 feet above the surrounding country; and at the western, 100-150 feet. On the northern portion of the Outer Upland the topography is complicated by several east-west mo- raines, the most important of which is the Marseilles moraine. This well-defined ridge leaves the Minooka moraine about 6 miles south of Aurora, and, following the south bluff of the Fox River, swings southwestward past Yorkville to a point near Millington, where it turns southward and, just outside of our region, crosses the Illinois River. Thus it forms the northern and western rims of the Morris Basin, as the Minooka does the eastern rim. It has a sharp crest throughout this course, and at one point south of Yorkville is 220 feet above the Fox River and 100 feet above the level of the surrounding country. The ridge, which is 2 or 3 miles wide, along this east-west stretch, has the knolls and depressions characteristic of terminal moraines, and is crossed by a number of curious gaps, no doubt cut by glacial streams. The Aurora Plain, so named because the city of Aurora is located on the middle of its eastern margin, is bounded by the Marseilles moraine on the south, the Minooka moraine on the east, and the Bloomington and Marengo moraines on the north, and extends westward beyond the limits of the region of Chicago. It is a flat area about 18 miles wide and extends into the region a distance of 15 miles, as indicated by dotted lines in Fig. 2. Its surface lies from 50 to 100 feet below the crests of the inclosing moraines. In the northwestern portion it is 850 feet above sea-level, in the northeastern portion 750 feet, and it slopes to 650 feet in the southern part. The Marseilles moraine reappears in the south- western corner of the region, and trending due east it . passes out of the area just east of the village of St. - Ibid., pp. 291 92. 28 THE OUTER UPLAND ','!» Anne, Illinois. There is an interruption in the moraine near it- eastern end, where the [roquois River crosses it. The crest of the moraine lies south of the region of Chicago, Mini therefore the elevations in our region are low, ranging from Too feel al the wesl end to <>."><» ;il the east. The moraine slopes northward, thus drier mining the flow <»f the tributaries of Ma/cm ('reek and Kankakee River. The relief is not great, bul swells 20 feel high occur on the moraine. Near St. Anne i- the eminence called Mount Langham that rises 75 loo feet alio\ e the plain to the north of it.' The eastern part of the Outer Upland, the Indiana portion. i- an upland only in a relative sense ^ con- trasted with the lowlands that surround it. It consists of a leu narrow hummocky moraine-, probably con- tinuations of the Marseilles moraine, that rise to over 700 feet above tide, and are separated by areas of sand and sandy ground moraine. The F<>\ River,' the only important stream in the Outer Upland, has it- source in southern Wisconsin, fol- low- the eastern and southern margins of the Aurora Plain, and after passing out of the region of Chicago 1 Ibid., p. -.'sip. - //„,/.. pp. 509 10. enters the Illinois River S3 miles below the mouth of the I >e- Plaines. For a di-tanee of nearly :.-> miles iron, its source the Pox River drain- only a narrow -trip among the tnorainic ridges ol the composite belt previously described. In this portion of its course it- rail a unts to but a few inches to the mile, but it .•xpand- at frequent interval- into lake- and marshes, between which are short -pace- having a narrow and well-defined channel ibove Elgin, Illinois, the river begins a rapid de-rent to the low plain thai lies on the outer border of the Marseilles moraine, and follows this plain to it- ith. The stream bas no valley until it begins the descent to this plain. where for a few miles it has cut to a depth of nearly 100 feet, hut in the pa— aye through t he plain it- bed i- -unk to a depth of only m or .".(I IVrt The valley is also narrow through- out it- entire length, and presents a conspicuous contrast to the broad valley of the upper Illinois. Its channel even in the lower 7.". miles has a breadth of only about one-eighth mile and a depth scarcely half as great as that of the neighboring portion of the Illinois. \ peculiarity of the Fox River i- thai all it- important tributaries li< the wesl side, there being bul a narrow strip of watershed on the east side. Chapter IX LAKE MICHIGAN AND ITS SHORE LINE I\KK Michigan, a complete barrier to cist -west A striking feature of the southern two-thirds of Lake land traffic is a principal cause for the devek)])- Michigan is the absence of natural islands. Submerged . ment of the great metropolitan area at thepoint reefs are found, however, though fortunately for lake -J where all traffic lanes water, rail, and highway navigation they are few. One of these, the Racine reef.'- — intersect and conic to a focus. The lake" is about .'500 miles long and has a maxi- ^ ^ ^ TABLE III mum width, at Racine, of SO miles. At Chicago the inMUes width in a due cast-west line is a trifle over .")() miles. ! . ... 12 -'•> The area of the lake is .22,400 square miles. 5 30-45 In cross-sections based upon soundings, the lake has ,.! the profile typical of an ice-eroded basin rather than of on i-n a river-cut valley, in that it is broad, flat bottomed, and .,- L , n - has somewhat abrupt sides. The longitudinal profile 3,1 ._>i- bears out the same view, for it shows the existence of 34 253 broad, inclosed basins separated by swells. The char- acter of the bottom in the part of the lake lying north occurs within the region of Chicago. Its inner edge lies of Racine is very different from that lying south of that over a mile offshore from the city of Racine: on its shal- city. In the northern portion the bottom is irregular, lower part it is 65— 11 feet beneath the surface of the due to the presence of what are apparently a series of lake, and it is surrounded by depths of 2.5-30 feet. In westward-facing escarpments protruding into the basin; extent it is a half-mile broad by a mile and a quarter in the southern portion the bottom is smooth and long. There is a lighthouse near its eastern border. The rounded. It is suggested thai the condition in the south- constitution and origin of this reef have not been de- em end of the lake is due to a veneer of glacial drift termined. covering the bottom and hiding irregularities which are probably present on the surface of the bed rock. ' " WGES ™ LEVEL OF LAKE Michigan 3 Along a line from Milwaukee to Grand Haven, the Seiches. — This is a tidelike rise and fall of the water lake nowhere exceeds 348 feet in depth (see Fig. 12). level set up in response to varying atmospheric pressures This relatively shallow stretch marks a submerged and rarely amounting to as much as a foot. divide which separates Lake Michigan into two major Tides. — Lunar tides having a range of about 3 inches basins. The northern of these is considerably the deeper occur on Lake Michigan. of the two, reaching a maximum depth southeast of Seasonal variations. — The range in level between low Sturgeon Bay of about 870 feet, or about 290 feet below water in January and high water in July or August sea-level. The southern basin reaches its maximum amounts to IS inches or less. This variation is due to depth in the middle of the lake, opposite the city of fluct nations in precipitation, spring melt ing. and evapo- Etacine, where the bottom is .">S'2 feet below the surface, ration. or approximately at sea-level. From this point south- Longer-term fluctuations. There are groups of years ward to the head of the lake the bottom rises gradually. during which the lake level is rising and others during The deepest part of the lake between Chicago and which it is falling. The variations between high and Benton Harbor lies at a midway point where the water low level do not exceed 1' feet. The years during is 252 feet deep. The rale at which the lake deepens oil' which high and low levels have been reached are shown the Chicago shore line is indicated by Table III. in Table IV. 1 Data drawn chiefly from the hike-survey charts furnished In llie I'niled Stales Lake Survey Office, Detroit, Mich. II 1 rmiMn (ii-nliujirnl and Natural History Survey, Bull. $6, p. 289. Data from the following sources: (a) ibid., p. 294; (6) P. C. Day, "Precipitation in the Drainage Irea of the Great Lakes." Monthly Weather Review (March, L926), pp. 85 106; (c) Herman L. Fairchild, "Changing Levels of the Great Lakes." Scientific Monthly 1 March. L926), pp. 193 200. 30 LAKE MICHIGAN AND ITS SIIORK UNI 11, ,-, nt changes in level. Since about 1 :»--**> there has been a steady lowering of the Greal Lakes that has caused some alarm and thai threatens seriously to inter- fere with the use of the lakes for navigation, sanitary purposes, and the generation of power in hydroelectric plants. Lake Michigan had a level of 582 feet above TABLE IV their work. Though they are always more or less active, ii i- at t i r 1 1< •-. when strong winds are blowing from the lake, particularly during storms, that they accomplish horn 184 I to 1855. to dale. sea-level in 1918; but in January, 1926, it had fallen to :•',' 37 feet the lowest level ever recorded for the lake. By August, 1926, the level had risen to 578.59, showing the usual seasonal fluctuation. This lowering of the water level has been attributed to the diversion of water at < Chicago from Lake Michigan into I he < Chicago Drain- age Canal, l>nt an exhaustive investigation by the Engineering Board of Review of the Sanitary District of Chicago has led to the distribution of the causes a> shown in Table V. Thus diversion at Chicago i- seen TABLE V Excessive evaporation and subnormal precipitation 13 Increased flow by the enlarged St. ( !lair River 8 Diversion al Chicago :, Storage and retention in Lake Superior ■'• Backwater effected by diversion and lowering in Lake Erie 2 Total below normal level 31 to be neither the sole nor the greatest factor involved. Abnormal weather conditions of recent years appear to play the leading part. The in' >~i favored remedy for this condition is the construct! f movable dams at the outlets of the lakes, by means of which the outflow and hence the level of each lake may be regulated. Such control has been sue- cessfully exercised at the outlet of Lake Superior for eight years and also l>y the Canadian government at the outlet of Lake Ontario, where it has resulted in the raising of the water level about . PHYSIOGRAPHY OF THE REGION OF CHICAGO Gary, as it has al so many other points. Throughout much of its length the dune bell is not over a milt- in width, but locally it is fully 25 miles wide. In the Indiana portion the finest stretch is that extending from Miller lu Michigan City; here the largest dimes are about 200 feel high. In .Michigan, however, the dimes reach their fullest development, especially at the deltas of rivers flowing into Lake Michigan where supplies of sand have been furnished not only by the lake but by iP**^' deposits cover a considerable area. Northeast and east of Washington Park a series of ten to I welve of t hese low ridges could be recognized before grading took place. They ran roughly parallel to one another and were from 1 In 6 miles in length, their southern ends being as a rule turned slightly to the west, giving them the form nf -hallow hooks. Thelongest andmost prominent ridge passed through the campus of the University of Chi- cago; it continued southward through the western part of Oakwoods Cemetery, terminating a mile north of Burnside. 1 South of Lakes Calumet and Wolf an. 1 north of the nearest beach ridge is a remarkable series of low parallel sand ridges which range from 8 to 1(1 feet in height and arc separated in many cases by narrow, marshy belts. From the present One Hundred and Thirty-eighth Street in Hammond to the Grand Calumet Riverninety of these ridges were once counted before grading had destroyed them. Similar ridges, approximately parallel to the lake shore, may be traced all the way to Gary and Miller in eastern Lake County. Lake Calumet. Wolf Lake, and former Lake George occupy a shallow depression or sand plain between the mass of ridges in Chicago and those in northwestern Indiana. This depression may once have been an open bay that was partially closed off as a result of filling. - The deposition of sand along the lake shore is still actively going on, and has given rise to the great sand areas that have become famous for their marvelous de- velopment of dunes. THE DINKS It is Dot so well known as it should be that the dunes of Lake Michigan are much the grandest in the entire world. Nut necessarily the highest, tin High some of them reach up Hill feel and more above the lake, but more than any other any- where, our dunes show magnificent and contrasting types of plant life, everything from the bare dunes to magnificent pri- meval Forests. No other dunes than ours show such bewilder- ing display- of dune movement and struggle for existence, such labyrinths of motion, Form, and life They are without a parallel. IIknuv Cu win. eh CoWLES. The Lake Michigan dune region' lies in a bell along the shore from Gary, Indiana, eastward and northward practically the full length of the east shore. Originally the dunes extended as far west as < 'hicago. but excava- tion for sand has destroyed them between Chicago and 1 Ctiujnipllir Sm-irlii nf t'liinltjn, Hull. I. p. Mi. Tin niy-second A mi mil Report I Dept. of Geologj and Natural Resources, [nd.), p. 37. ; S. T. Mather, Report on the Proposed Sand Hums National Park, Indiana, p. 4(i. 1 There are manj publications describing the dunes in detail. A selected lisl of these works follows: (a) C. \V. Shannon, "The Sand Areas of Indiana," Proceedings of the Indiana Academy of Science for 1911, pp. L97 210; (6) Edward Barrett, "The Dunes of Northwestern Indiana," Forty-first Annual Report (Dept. of Geology and Natural Resources, [nd., L916), pp. II 27; (c) S. T. Mather, Report on the Proposed Sand Hums National Park, Indiana (Washington: Dept. of the Interior, National Park Service, L917), p. 113; (d) <>. M. Schantz, "Indiana's l'n- Ipportunity," National Geographic Magazine, Vol. XXXV. No. 5 (May, 1919), pp. 130 H; (e) E. S. At the Sooth End op Lake Michigan the Beach Is Being Widened by Deposition- of Sand from the Eroding SlIllHE XOHTH OF CHICAGO. the rivers. At Sawyer, Ludington, and (Hen Haven oc- cur the most imposing dunes, some being over 400 feet high. A few small dune areas occur along the west shore of the lake also, between Waukegan and Kenosha, but here they are relatively inconspicuous. The dunes have been formed as a result of winds blowing from the lake across areas of sand that have been freshly deposited along the shore. We have con- sidered how this sand is obtained through the erosion of the west shore north of Evanston, and how it is carried around to I he head of the lake by "shore drift." Thus is explained I he existence of great dune areas along the Indiana and Michigan portions of the shore line and the paucity of dunes along the Illinois and Wisconsin portions. The dunes are best developed where the winds from the lake have passed over broad tin mea— a National l> d Dunes of Indiana LAKE MICHIGAN AND ITS SHORE I. INK expanses of lake, and as a consequence have developed high velocity. Such winds, especially, are t lio^c from the southwesl and northwest (see wind rose, Fig. 9 . There is hardly a time when at some point Minim the sand inland, buil the land. It will prove typical dune. W line dunes in the get of the sti lake Sand l>' m - It, in i\<. mi Pine Pobest, v Typical Landsi ipi i\ THE N < .it i hi us Imh !\i 1)i m ... beach pick up particles of sand and carry them inland. Where some obstacle is encountered, the velocity of the u nmI i- checked and the -and i- dropped. So dunes may originate about clumps of grass, shrubs, etc. The em- bryonic dune itself becomes an obstacle, and rapid growth take- place. Mca nu li ile. I lie dune mOVeS inland a- a result of the rolling of -and up il- gentle, n indward -lope ami over the crest to it- steep, leeward dope. Along Lake Michigan it has been found that dun,- may move as rapidly as 10 or 15 feel per year. In it- inland journey, the dune may encounter shrubs, tree-, even whole forests, and engulf them. Only those forms of vegetation can then survive that have the power of putting forth new roots and growing upward as the sand pile- an I their base; in I he cm f the largest dunes, nothing survives. Later, dead tree trunks are exhu I when the dune has passed completely by. Eventually the "wandering" dune slows up as a result of the cutting off of it- -and supply by new dune- that have formed between it and the shore. Vegetation then gains foot- hold on it. thus contributing to stabilization. With time the dune will probably become "fixed," though not infrequently dunes that are apparently fixed become juvenated .pasbefoi i-aiu ,nlv to -I, / ' the dunes. The plant life of the dun,-, and in fact the dune- themselves, have become celebrated as a n-iili of the classic studies of Professor Henry C. Cowles. A resume of the botanical features is given on sandy shores winds from the lake are nut carrying the pages ; 9. The bird and animal life are :il-, . extremely inter- esting. Concerning the former, Mr. < > M. Schantz, of the Audubon Society, says: The lisi of lard- regularly visiting the area comprising the .'line- and the adjacent regions is a \,T\ lari;,- ■ well over :;ki varieties; and the list is often swelled by wandering visitors who are attracted by the wonderful I' I supply, an, I the Favorable climatic conditions. 1 Professor Elliot R. Downing states that the region i- exceedingly interesting t>> the animal lover be- cause it i- an extensive stretch ,,1' wild countrj with plenty of cover in which the small animals find shelter; it is consequently also the haunt of some of the larger predaceous animals now ii, ii!> extinct elsewhere hereabouts. In the last five years I have Found the j;ray timber unit' there once, foxes several Inn,-, raccoons, porcupines, rattlesnakes, and nearh everj year the bald eagle has been seen nesting somewhere in the region lust as the flora of the dunes is a curious mixture S8U»*r1 Large Vm IN li \ I l.lln II. I l>l M- il \\ I Itl I \ It I MO' El EVATION IN nc R irlhcrn species, like the cactus and arbutus, that -r..» side bj side, -•■ there arc found animals there as neighbors that represent the desert conditions of the South- wesl and the | line barrens of the North. Such represental ives ,,f usuallj widely separate Faunas arc the six lined lizard that runs i ver with such celeritj and the ruffed grouse that a- a ml ly nests in the pine Forests several hundred miles ,.f it,,- [nt( PIIYSKHiRAPIIY OF THE REGION OF CHICAGO farther north. Yet both these animals arc quite c< the dunes You also find a group of animals naturally foreign to this latitude Imt brought here by plants thej in- habit. The varying hare, porcupine, and chipmunk arc here: such hinls a^ the wood pewee and red eyed vireo nest in the mixed evergreen and birch thickets; the Pickering tree frog peeps his love song; and numerous woodboring beetles and hark tunnelers that infest only the conifers an' found abund- antly Because of the congenial cover afforded by the evergreen thickets and the abundant t I. many birds arc found during the spring and fall migrations, staying days and weeks in the dunes, that would not loiter at all in the Chicago region were it not for the attractions of this particular sec- tion. Such are the raven, cross-hills, kinglets, black-throated green and pine warblers. So too the many lakes and swamps of the region, lying in the depressions between the sand ridges, are ideal shelters tor the waterfowl on their way to or from the extensive marshes that lie near to the south. Wild geese. ducks of all sorts, loons, coots, gallinules, rails and a variety 1 Ibid., pp. 93-94. of snipes are all annual visitors and some of them regular residents.' • ONSERA ATION OF lilt 1)1 M - At numerous points large areas of sand dunes have been excavated by steam shovels and hauled away to be used tor construction purposes. While a reasonable amount of such excavation may perhaps be justified, the destruction (if some of the very finest dune area — as at Dune Park — is nothing short of tragic. It is a source of gratification that a large area, already Hearing 2,000 aeres, has been acquired by the Indiana Department of Conservation asa state park. Michigan, also, has taken steps to protect some of the most valuable areas by creating state parks, and the total destruction of the beautiful dunes is thus not likely to occur. It is sincerely to be hoped that further protective measures will be taken either by the state or federal governments. Chapter X THE BED ROCK AND ITS SURFACE, A BURIED LANDSCAPE SEVERAL Formations are represented in the bed ruck of the region of Chicago. These arc com- posed of limestone, sandstone, shale, and coal, limestone being by Far the most common rock type, coal the leasl so. Fossils found in the rocks indi- cate thai the various formations were in greal pari laid down ;ii the bottom of seas which time after time over- spread the central pari of the continent. The fossils also enable geologists to determine al whal time in the course of geologic history these rocks wen- Formed; and by their use it has been Found thai in the region of Chicago formations representing the fol- lowing geologic periods occur: Ordovician, Silurian. Devonian, and Pennsylvanian. All of these periods dale far hack into geologic time. Thus the rocks of the region of < Ihicago an- exl remely ancient, their age being meas- ured in terms of millions of years. Originally nearly horizontal, the strata of Hie region have been slightly deformed so thai their general dip is toward the cast. Ordinarily tins dip is so slighl as to be imperceptible. Because of this structure, shown in Fig- ures 1 and 5, the younger formations, those of the Devonian period, are al the surface III the eastern part of the region of Chicago and older rocks successively come to the surface as one goes west ward. In the south- western corner of the area, however, these older rocks arc overlapped by the younger formations of the Coal Measures. The latter are Continuous southward ami arc part of an area known as the "Eastern Interior Coal Basin" thai comprises mosl of the state of Illinois. HI -i RIP] |i i\ hi |i i|<\| \ in i\s The following are generalized descriptions of the formations occurring in the region of Chicago, They are given in the order of then- age from oldest to young- est, and arc located in Figure I I The St. Peter formation occupies a small area in the southern part of Kendall County. Il consists of a sand stoi f unusual purity thai is usually snow white where freshly exposed. As a rule the sand grains thai compose it arc well rounded and l.ut slightly cemented: conse- quently the rock is soft and easily eroded. Il is chiefly in this soft standstone thai Starved Rock and the many neighboring scenic features have been erode I. Because of its high purity and softness this formation is an im- portant source of sand for molding and glass-making, and due to its high qualities "Ottawa sail I"' has I, ecu adopted by the American Society For Testing Mali-rials as a standard for the line aggregate in concrete. The Galena-Platteville formation is a limestone and magnesian limestone (dolomite) formation that occupies two areas: one in the northwestern corner of the region, in Wisconsin, and one along the middle portion of the western margin of the region, from central Kane County south to northern Grundy County. It is a hard. j;ray. Or buff limestone I hat appears massive in fresh exposures lull thin bedded and "slaliliy" where weathered. The Richmond formation extends in a narrow licit through the western pari of the region from the northern boundary as far south as the Illinois River between Joliel and Morris. An isolated patch occurs along the Kankakee River near Wilmington. It consists of a gray- ish bluish, or greenish shale in which occur layers of limestone that vary from fine to coarse textures. Where freshly exposed the limestone is gray, hut it weathers to a I. row 11 color. Because of the shale it contains, the formation is relatively non-resistanl to erosion. The Alexandrian series comprises two thin limestone formations, the Edgew I and the Kankakee, at the bottom oftheSilurian system. Theydonol differgreatly from the much thicker and more extensive overlying Formation, the Niagaran, and are therefore nol differ- entiated from the latter on the geologic map. The Niagaran formation is the mosl well-known formation in the region, because of the prominence <>f its outcrops, as at .loliet. and because of the limesl • industries to which ii has given rise. It is a hard dolo- mite, blue or gray on fresh surfaces and yellow where Ion- exposed, It occurs In well-developed layers show- ing a wide range in thickness fr less than an inch to •J or :> feet. Its distribution, as shown on the geologic map. COVerS more I hall t Wot hi ids of I he Chicago area. PHYSIOGRAPHY OF THE REGION OF CHICAGO GEOLOGIC MAP OF THE * REGION OF CHICAGO Fig. I i. Geologic map of the region of Chicago. (Data furnished by the U.S. Geological Survey and the 111. Geological Survey.) THE HIM) R()( K AM) ITS SURFACE In the eastern pari of the region <>f Chicago in Iiuliana (lie rin'k< encountered in deep «dK have been found to be Devonian in age. 'liny include a shale for- mation NCu AJbany), a limestone (Corniferous), and a sandstone Pendleh >n II \\-l IV V\I w The formations of the Pennsylvanian, together con- stituting the Coal Measures, lie in the southwestern corner of the region, their distribution corresponding roughly to the Morris Basin. The three fori nation- thai arc recognized the Pottsville, Carbondale, and Mc- Leansboro named from bottom to top in a vertical sec- tion exhibit greater diversity than do the other for- mations that have been described, consisting of alter- nating beds of sandstone, limestone, -hale, and coal. The coal occurs iii layers up to :: feel thick, thai i-. in workable layer-. This i- the nearest occurrence of coal to Chicago. -I HI M I hi i hi in ii BOCK Though the surface of the bed rock i- largely bidden beneath the great accumulations of glacial deposits left by repeated glacial advances, conclusions relative to its character may be drawn from data obtained in drilling wells, digging foundations, etc. These data indicate dearly that the surface of the bed rock is not flat but i- diversified by the presence of ridges, hills, and val- leys in much l he same fashion a- i- our presenl land- scape. Indeed, we are here actually concerned with a buried land-cape, that which existed prior to glaciation. It- major features an- unchanged, though it i- known that the overriding glaciers in - e cases rounded oil' the hill- and -cured out Hie valley- thai trended m Hie direction of the in- flow. While data are not yet numerous enOUgb Iii make possible the construction of a map of the entire region of Chicago showing the feature- of the buried preglacial surface, several such map- have been made for pari- of the area that have been Studied in detail. Dr. William ('. Alden, of the United Slate- Geological Survey, has prepared a map for southeastern Wisconsin; 1 and Pro- fessor D.J, Fisher one for the Joliet region. 1 These maps an- of meat interest, and indicate that the preglacial topography was very similar to thai of the present sur- face, though a- a rule more rilled: and thai the elev .,- tions and lowlands of the present surface do not usually correspond to elevation- and lowlands in Hie Led rock beneath. For example. Hie Chicago Plain i- nearly il.-it . yet the underlying Niagara limestone ha- an extremely uneven surface. On the plain I he drift mu-t be thin over Publu ■ Publia rical Sum ii. Profi Illinois Geological Surrey, Hull. .'.;. the bed-rock hill-, and thick over the lied-rock low- land-. Such lack of correspondence between the bed- rock topography and the surface topography i- the rule throughout the region of Chicago, though exception- occur, a- in the case of the Lake Geneva Basin, which corresponds to a preglacial valley of considerable size. The character of the lied-rock surface involve- im- port an I practical considerations. It is often desirable, for example to lie alile to predict the depth to which wells and foundation- mu-t lie -link before they will reach the lied rock: hut the nature of the bed-rock -ur- face i- such that often predictions can !»• made only within wide limits. Al one point the bed rock may be quickly reached because a buried hill or divide i- en- countered; whereas at a point only, a few hundred feel away it may lie necessary to proceed ."ill or Kill feet deeper because of a buried valley. Attempts to map in detail the buried bed-rock topography underlying the downtown section of Chicago have been made, hut to date with no great SUCCeSS, due to the lack of -llllii lent recorded information. Could such a map lie prepared with accuracy it would he of great value. The -lope of the surface, the solidity of the rock, and the character of the material resting on the lied rock are of importance in connection with the laying of foundation- for high buildings. Caisson-workers find it necessary to continue their hole- for some distance after -t riking rock in order that they may feel fully assured that they have reached -olid bed rock and not some loose and insecure ledge. Fortunately, the glaciers in most cases stripped off most of the decayed portion- of the lied rock and left a dean. linn surface. Ill M Till HI 11-KiH k -I HI \. I The depths at which lied lock now lie- an- indicated in part by the -oil map (Plate IV which -how- the areas where soils re-t direct lv on lied rock (usually less than :s t i and in pari by Figure 15 which -how- in gen- eralized form the relali. f the bed lock to the present surface. Leveret t make- the follow ill- -latemenl alioiit the area : 'I'll.- thickness of the drift is so great in tin- northeastern Fourth of Illinois as to convej a false idea of the altitude of the rock surface in that region. Were the drift coating entirely re- moved, the average elevation would probahlv be as Ion as the surface ol Lake Michigan, ami possiblj it would uo1 exceed .on feel above tide. This low altitude extends eastward - e distance into Indiana. The low altitude of this district, as well a- that "f tin- Lake Michigan basin, probabh influenced the ice How and inv it.d it- great southward extension in I of Illinois. 4 /' ii rum , 1914), p, 590 ' / 'nitea ' p. 8. to PHYSIOGRAPHY OF THE REGION OF CHICAGO On the Lake Plain in the vicinity of Chicago, the bed rock lies from to 130 feel below the surface with an estimated average of .">() feet.' A map prepared by Samuel <>. Artingstall, ;i former city engineer of Chi- cago, showed a valley with a floor 100 l L 2."i feel below the level of the lake crossing the north-central part of Chicago and entering the lake south of Lincoln Park- CD »lo 50 feet I E23 Ovens Feeilhick I'ii,. 15. Depth iif r.«k mantle. Map (after Leverett) showing average thickness of the glacial debris in the central part of tin- region .if Chicago. In the outlying parts not shown, these surface materials are over 75 ft. in thickness drift for points Levered givesthe follow ingthi ■k. esses of on the Lake Plain in m rthen Ii diana: 8 Hobart \in-i heastern •orter < lot nty Michigan Citj A few outcrops occi r on 1 ,c Lake PI or ridges of t be l>c. ■ United stairs Geological Survey, Mo log. IS, p Ibid., pp. 125 86. 1 Ibid., p. 885. ones; others occur at Bridgeport, Hawthorne, River- side, and Lyons, al Twenty-ninth Street and at several places within the city of Chicago. In the Chicago nutlet. 3 except where terraces occur, the bed rock is at or relatively near the surface through- out, as a result of the stripping that took place during the great How of water through the outlet. The cliffs between Joliet and the head of the outlet afford by far the most extensive exposures of Led rock in the region of Chicago. Between Summit and Lemont the solid rock is only occasionally seen at the surface, although the floor of the outlet is littered with coarse river debris consisting largely of limestone blocks. From Lemont to Joliet the exposures of bed rock are almost continuous. From Joliet to the head of the Illinois River about half the floor is covered with drift or river debris so that the depth to bed rock is not known; the remainder is cither bed rock or rock covered with a thin deposit of coarse river debris. The part of the outlet that crosses the Morris Basin has a floor of shale either exposed or cov- ered with a thin deposit of sand. On the Lake Border Upland the bed rock is deeply buried under glacial drift. The following depths to bed rock are reported by Leverett: 4 Feet Lake Forest 160 Highland Park Kiu-7.5 Winnetka 150 Near Northbrook .147 At Racine the thickness of deposits on bed rock varies from 100 to 125 feet; at Union Grove a thickness of 195 feet was found, the maximum for Racine ( ounty. ' No out crops of consequence occur in the Illinois por- tion of the province. In Wisconsin outcrops that deserve mention occur at Ives and along the lower part of Root River, in Racine County. 6 On the Valparaiso Upland the bed rock lies far below the surface. In Kenosha County the drift is gen- erally from .")() to 100 feet thick and in many instances 100 220 feci thick. 7 At Burlington, in Racine County, the drift is 50 or 60 feet thick. The usual range for this county is reported as being from 25 to 100 feet. In Wal- worth County thicknesses up to 329 feet are known. From the Illinois and Indiana portions of this up- land Leverett 8 reports the following depths at which bed rock was encountered : Al Ivanhoe, III., on crest ' llllls Near Lake Zurich, on crest ie ex- Crest east of Warn inula good Crest south of Barrington ■■ Wisconsin Geological and Natural History ■ >Ibid., Bull. ;j.|.. 135. Ibid., Bull. 35, p. 895. / niied States Geological Survey, Monog. 38 THE Bill) ROCK AND ITS SURFACE '"' feel along the Minooka moraine to 20 or 30 feel nexl vi:;!Jt::;\:z::" Z.Z ^^-^y^ ** n .-. NearSchaumberg, along , rest bas an avera « e de P th '" l "'' 1 rock "'' :: " in { «*< •""• "> Arlington Heights, al ou1 150 feet below crest 128 P laces f* 3 ;|1 Manteno rock ridges rise to the surface of Crest south of Bloomingdale 162 ,l "' l ll;lln '"" l outcrop. [taaca 72 1" the Morris-Kankakee Basin bed rock is al or Bensenvillc 91 near the surface throughout the Illinois portion. I{<- Ehnhursl us garding the Morris Basin, Leveretl states as follows: Cre81 "' N »l ' " i,le ' easl ' '"' The drift along the border of the Marseilles raine has DownersGrove 113 generally a thickness of 100 feet or more, bul upon descending < rest northwest ol Lemon! ISO ,,„. ,.,,„. ,„„..„,, ,,„. bead (>r ,,„. j| |n|( „ s ||lr thickness ,,. Crest ... moraineeasl ol Lockporl 115 ,,.,,,_, and ,,„,.,. ;l ,,. extensive iiri ,„ m ,,„,,,,, Gnmdy Monee, on crest 180 southwestern Will, and northern Kankakee counties, where l!, ''''''"' r ""' rock is encountered at very slight depth, so that the shallow ■ hica *° He 'S hts :i " ravines and shallow wells and even the cellar bottoms reach it.< Crown Point, [nd 176 Hebron 108 As shown on the soil map, there are large tracts wesl Valparaiso 125 of Kankakee and south of Momence where the sand Laporte 295 rests dinvtly on bed rock and a number of outcrops Two miles north of Wheeler 200 occur. N,: "' ( " l " ir « l,s In the Older Upland the bed rock through the 88 northern portion (except over the Aurora Plain is deep- The foregoing data indicate thai thegreatesl depths ly buried; Leverett 6 reports thicknesses of glacial drift to bed rock are encountered in the northern and eastern ranging from less than 100 360 feet. In the southern portions of the Valparaiso Upland, and the lesser part of the Aurora Plain the bed rock lies within 20 10 depths in the middle portion. feel of the surface" and some outcrops occur along the Oiiicr,,,,. are rare. In the town of Spring Prairie, in Fox River. The depth of the bed rock over the middle Walworth County, there are a few. In Racine County portion of the Outer Upland ranges from over 100 feet there are outcrops wesl of Burlington. 1 In the Illinois al the western end to about 60 feel in the vicinity of portion, outcrops occur al Elmhurst, in Du Page St. Anne. In the Indiana portion of the Outer Upland County,* and near La Grange, in Cook County. the drift is probably everywhere over 100 feel thick On the Manieno Plain, according to Leverett,' the except south of Medarville in Pulaski County, where depth iif bed rock in the northern part ranges from 100 the drifl begins to Hun toward the south. H Geological and Natural History Survey, Bull. 3$, p. 74, I C . . need Survey, Bull. («, p. 113. 1 United States Geological Survey, Monog. 18, p. 325. ' Ibid., pp. 315-lfl ' Ibid., pp. 292, S11 12. I p. 283. Chapter XI THE SURFACE MATERIALS, BASIS OF OUR AGRICULTURAL WEALTH S[NCE the thickness of the materials overlying bed rock ranges from to :!.">0 feet in different parts of the region and for t lie most part ex- ceeds 15 feet, it is evident that the surface ma- terials and not the bed rock constitute the major factor in determining the geographic development of the region. Glacial drift, often called "bowlder clay" or "till," constitutes the great bulk of the surface material over the region of ( Ihicago particularly on the uplands and plains. It was either heaped up under the edge of the glacier in the form of terminal moraines or left under the body of the glacier to form the more level deposits known as ground moraines or "till plains." Ordinarily the drift is composed of a matrix of blue or buff clay in which are imbedded stones of various sizes and kinds. Glacial drift has aptly been characterized as "homogeneous in its heterogeneity." and its lack of assortment affords a reaily means of identification. While the stones gen- erally range in size from small pebbles to moderately sized bowlders, they are occasionally found as large as 12 IS feel in diameter. In the region of Chicago most of the stones arc of limestone: there is, however, a fairly high percentage of granitic rocks and other types foreign to the immediate vicinity but known to occur in the country over which the glacier moved, that is. north and northeast of the (ireat Lakes region. It is to be noted that the larger bowlders arc ordinarily of these foreign-rock types for the reason that they are more resistant than the lime- stone. The stones tend to be angular in shape and flat faced, very unlike the pebbles modeled by water on shores and beaches. Scratches may sometimes be found on the rock faces, indicative of glacial origin. The clay in which the stones occur consists of pulverized rock in which limestone is again the most important constitu- ent of the various kinds represented. The upper 2- or 3-fool /one ill a deposit of glacial drift is often buff in- stead of blue, as a result of oxidation at (he surface: and in this portion the limestone is more or less leached out. The loess is a fine, wind blow n material, usually light bull' in color, that i any parts of the region a few inches to several feet. It is believed that the loess was derived from finely ground rock originally spread out in the stream valleys and bottom lands flooded by water from the melting glacier. This light, flourlike stuff was subsequently whipped up from the outwash flats by the wind and carried out over the uplands. The loess differs strikingly from the glacial drift upon which it usually rests in being free from pebbles and bowlders. No doubt it was formerly more widespread than is now the case, having been stripped away from many locali- ties by erosion. Though poorly developed in the region of Chicago as compared with the great thicknesses in which it occurs in the nearby Mississippi Valley, the loess is nevertheless of very great importance, for it is largely from it that our present soils have been de- veloped. Gravel occurs in large deposits in the northwestern part of the region of Chicago (see glacial and soil maps i, chiefly along present or former drainage lines. The de- posits take the form of gravel hills or of broad plains according to manner of deposition. The outwash plains are the most common and extensive form of deposit, though frequently, as near Joliet. they have been dissected by streams so that they are now no longer continuous plains but terraces instead. The gravels were deposited by water flowing out from the melting glacier, and have the characteristics of water-laid ma- terials in that ( 1 ! they arc stratified. (2) they are rough- ly assorted according to size, and (8) the materials of which they are composed are more or less rounded. The extremes of size that characterize glacial till arc here Sand occurs along with gravel as an outwash de- posit : frequently the gravels arc sandy or are int erst rat i- licd with beds of sand, and some entire outwash de- posits consist of material no coarser than sand. In the Morris-Kankakee Basin sand makes up the bulk of the surface deposits, gravel being present in insignificant quantit ies. /,,//,-, deposits. While it may seem surprising that lacustrine clays should be practically absent over the Lake Plain since it was so long under the surface of Lake Chicago, nevertheless t his is the case. Possibly the 5URFACE MATERIALS, BASIS OF 1)111 AORKTI. II RAI. WEALTH finer materials suspended in the lake water were carried away by the vigorous current thai flowed toward and through iIk 1 < Ihicago outlet : or, if any deposits did form the lowering of the water level during successive hike stages may have enabled the waves I" cut into an■. p. S6. ' Uml.. pp. 6 7. Physical Composition. T times referred to as "texture, characterizing a soil. Tl I roporl ions of t he follow ing phj sical constituents: clay, silt, fi,i'- -and. -and. gravel, -tone-, and organic material. Structure. The term "structure" has reference to the ag- gregation of particle- within the -oil ma— and carries such qualifying terms as open, granular, compact. Organic-Matter Content. The organic matter oi soil is de rived mainl} Iron, plant tissue and ii exists in a more or less advanced stage of decomposition. « trganic matter constitutes formal ion. Color. Color i- determined to a large extent bj the pro- portion of organic matter, but at the same time it is modified by the mineral constituents, especially bj iron compound-. Reaction. The term "reaction" refer- to the chemical state of the soil with respect to acid or alkaline condition. If also involves the idea of degree as strong!} acid or strongly alkaline. CarbonaU Content. Thecarl ate content has refer to the calcium carl ale (limest ■< present, which in some cases maj be associated with magnesium or other carbonates The dept I, at » hich carbonates are found may become a ver} important lac tor in determining the soil tj pe. Topography. Topograph} has reference to the la} of the land, as level, rolling, hilly, etc. Native Vegetation. The vegetation or plant growth before being disturbed bj man. as prairie grasses and forest trees, ,- a Feature frequently recognized ,,, deten ing soil types. Geological Origin. Geological origin involves the idea of character of rock material- composing the soil as well as the method ol forma I the soil On the basis of the foregoing factor-, the S, had mapped the following soil typ C ,tv. The list ,- selected a Chicago, a I pland Prairie Soils Brown Sill Loan, Black Claj Loan, ltrou ,, Sand} Loam Brown Silt Loa i Tight CI i/ Experimental Station, Bull. 19, :urring in Grundy I for the n PHYSIOGRAPHY OF THE REGION OF CHICAGO Brown-Gray Silt Loam on Tight Clay Brown-Gray Sandy Loam on Tight Clay Brown-Gray Clay Loam on Tight Clay Brown-Sandy Loam on Gravel 6) Upland Timber Soils Yellow-Gray Silt Loam Yellow Silt Loam Yellow-Gray Sandy Loam Dune Sand c) Terrace Soils Brown Silt Loam Black Clay Loam Brown Sandy Loam Yellow-Gray Silt Loam Yellow-Gray Sandy Loam Brown-Gray Silt Loam on Tight Clay Brown-Gray Sandy Loam on Tight Clay Dune Sand Black Sandy Loam Brown Sandy Loam on Rock Brown Silt Loam on Rock Brown Sandy Loam over Gravel Yellow-Gray Sandy Loam on Gravel Brown Sandy Loam on Gravel d) Swamp and Bottom-Land Soils Deep Brown Silt Loam Mixed Loam Black Clay Loam Brown Sandy Loam Black Mixed Loam Peaty Loam on Clay Medium Peat on Clay Deep Peat Muck on Clay Muck on Marl e) Residual Soils Brown-Sandy Loam on Rock Yellow-dray Sandy Loam on Hock Rock Outcrop The composition of these soil types is indicated by the following table of standards used by the Survey: Peats — Consisting of •'!■"> percent or more of organic matter, sometimes mixed with more or less sand or silt. Peaty foaww— Soils with 15 to •'!."> percent of organic matter mixed with much sand. Sonic silt and a little clay may lie present. Murhs Soils with l.» to 35 percent of partly decomposed organic matter mixed with much clay and silt. Clays Soil-, with more than 25 percent of clay, usually mixed u Mli much silt. Clay loams Soils with from 15 to 25 percent of clay, usually mixed with much silt and some sand. Silt loams Soils with more than 50 percent of silt and less than 15 percent of clay, mixed with some -and. Loams Soils with from .'!(! to .")() percent of sand mixed with much silt and a little clay. Saudi/ loams Soils with from .">() to "."> percent of -and. ' Ibid., Soil Rep. 16, p. 15. Ibid., Soil Rep. 26, p. 1 Fine sandy loams- Soil- with from 50 to 75 percent of fine sand mixed with much silt and a little clay. Sands Soils with more than 7.5 percent of sand. Gravelly hams — Soils with '-'."> to .">(> percent of gravel with much sand and some silt. Gravels Soils with more than .30 percent of gravel and much sand. Stony loams — Soils containing a considerable number of stones over one inch in diameter. Rock outcrop — Usually ledges of rock having no direct agri- cultural value. 1 AYhile a detailed consideration of all the soil types occurring in the region of Chicago lies beyond the scope of this report, the characteristics and distribution of the main groups may be briefly outlined. UPLAND PRAIRIE SOILS Owing to the accumulation of organic matter, derived very largely from the roots of the prairie grasses that once covered the land, the soils of this group are dark in color, vary- ing from dark brown to black. The network of comparatively thick roots of these grasses was protected from complete de- composition by imperfect aeration resulting from the covering of fine, moist, soil material. The flat prairie contains a higher amount of organic matter than the more rolling land because the grasses grew more luxuriantly there and the higher moisture content retarded the decay of their roots. The ma- terial resulting from this partial decomposition is a black sub- stance of varying chemical composition. Some of it has prob- ably been in the soil for many thousands of years and has reached a stage similar to coal. It is almost wholly resistant to decay. This old organic matter, as well as that more recent- ly formed, gives a dark color to the soil. 2 This group has much the widest distribution of any in the region of Chicago. It reaches its most extensive development on the uplands, particularly south of the Chicago outlet. In the rougher portions of the uplands, in Indiana, northern Illinois, and Wisconsin, this group of soils is confined to the higher parts of the moraines. UPLAND TIMBER soils The Upland timber soils occur as irregular zones along streams and on or near somewhat steep morainal ridges. They are characterized by a yellowish grey color, due to their low organic-matter content. The deficiency of organic matter has been caused by the long-continued growth of forest trees. After the forest invaded the prairies two effects were produced: first, the shade from the trees prevented the growth of prairie grasses, the roots of which are mainly responsible for the large organic-matter content in prairie soils: second, the trees them- selves added wry little organic matter to the soil, for the leaves and branches either decayed completely or were burned by forest fires. Furthermore, the organic matter that had been produced by the prairie grasses became gradually dissipated during the occupation of the land by the trees. As a result, the organic-matter content of the upland timber soils has RFACE MATERIALS, BASIS OF <>!]{ AGRICULTURAL WEALTH been reduced until it is decidedly lower than thai of the ad- jacent prairie land. Several generations of trees were neces -ar.\ to produce the present condition of 1 1 1 » - soil. 1 In addition to the belts of I lu-^<- soils thai usually \<- fined. In Lake and Porter counties, Indiana, for ex- ample, the loams grade into sandy soil so gradually thai ao exact line between t he t wo groups can be drawn. In many places, as on the Valparaiso Upland in Indiana. the loam is derived directly from glacial drifl and hence i- -omcwhai bowldery or gravelly. The deposits in the Kankakee Basin, particularly easl of Kankakee < lountj . are sandy soils; bul because of the fact thai they are poorly drained ami the area which they OCCUpj is sub Jed to frequenl Hood-, they have - of the character- istics of alluvial or peaty -oil-, being frequently silty and high in organic content. The same i- true of the sandy deposits on the Lake Plain. These soils have been put iii the sandy -roup inasmuch as their high sand content i- their mosl distinctive feature and the one likelj t" be of mosl significance in connect ion with road- building, excavation, etc. The line between the -alidy soils and the dune sand is necessarily arbitrary. Nol all of the dunes have Keen mapped, particularly in the southern portion of the Indiana portion. ' Ibid Mi PHYSIOGRAPHY OF THE REGION OF CHICAGO A few outstanding features shown on the generalized soil map may be pointed oul in connection with each soil type. ' Fine soils constitute the mosl widespread type oc- curring over the greater part of the Lake Border Up- land, the Valparaiso Upland, the Outer Upland, the Manteno Plain, and over large areas of the Lake Plain and Morris-Kankakee Basin. Their distribution corre- sponds closely to the distribution of the glacial drift. Sandy sails are found chiefly over areas where water has been the agent of deposition, though often the sand deposits have subsequently been affected by wind ac- tion. They cover much of the Lake Plain and the Morris-Kankakee Basin, a part of the Valparaiso Up- land in Laporte County. Indiana, where a peculiar sandy phase of the glacial drift occurs, and various outwash areas in the northern part of the region, especially in McHenry and Walworth counties. Dune sitinl in the greatest quantities occurs on the Lake Plain, in northern Indiana, and on the Kankakee sand plain. A few stretches of dune are mapped along the strip of Lake Plain between YVaukegan and Kenosha. Bottom-land sails form narrow strips along the streams, particularly those subject to overflow, and irregular-shaped patches occupying lowlands. They are important in the rougher morainal areas, where depres- sions are numerous and drainage is poor. Peat is confined to poorly drained depressions in the glacial moraines and to swampy lowlands along the streams and on the Lake Plain. Often the peal deposits assume the form of roughly circular patches, more or less completely surrounded by bottom-land soils. Chapter \ll THE GEOLOGICAL RESOURCES OF THE REGION itcro ,i I, IEMESTONE. 1 The r nished limestone for commercial use in the re- . gion of Chicago are located (1) in the Chicago -J outlet along the bluffs of the Des Plaines Qlinois Valley; ■ --' in the bluffs of the Fox River Valley in Kane County, south of Elgin; and (3) in the Morris-Kankakee Basin west of the Indiana-Illinois state line. Areas of lesser importance are l Thornton, in Cook County; (3 Elmhurst, in Du Page County; (3) I\«--. in Racine County. The most importanl area in the region of Chi- cago i- the section of the Chicago outlet between Surnmil and Juliet. The quarries of the region have furnished rock ma- terial for road metal, concrete, railroad ballast, flux in the iron industries, cement, building -lone, flagstone, "riprap," and "agricultural limestone" Clime for fer- tilizer Regarding tlie quarries of Cook County, the report of the Qlinois Geological Survey has tlie following t<> say : every outcrop of limest • of any consequence in the county. \l..-t of these quarries operate on a large scale and are equipped to crush rock to any size. The market For the crushed stone i- t" a great extent local, that i-. in Chicago and its environs, but considerable shipping is 'I • to the south, to make use of the empty coal cars returning to the mines over tin- Illinois Central Railroad. 1 The quarries of < ook C ity are located at Thorn- ton, Lemont, Sum nut. McCook, Lyons, Chicago, rlodg- kins, l.a Grange, and Bellwood. In most of these the output is used for c Tele, mail materials, railroad ballast, and agricultural limestone. In a few lime is pro- duced. Chicago is one of the three leading limestone- producing cities of Illinois, the other two being Quincy ami Alton The quarries of Cook County having the largest production of crushed limestone are those al Mellu I. Hodgkins, Thornton, and McCook, with daily outputs ranging IV 2,400 to 1,000 tons The total annual output ranges from ■">. ,000 to 6,000, The rock ite.l in digging the ( Ihicago 1 The reader is referred to tin- Following excellent diaciu i i ■,,„.,. 1983 Pp 194 / !.,p IIU age Canal was piled up in the form of "spoil hanks" along the side, forming a long ridge varying fr Hi to ."iti feel high. This ridge offers a large supply of readily obtained rock some of which is used for filling cribs and breakwaters along Chicago's lake front. 1 Joliet was e the center of a very important stone industry and formerly furnished much building stone, as is witnessed by the numerous imposing structures in Joliet and neighboring cities built of Niagara limestone, .«#&.;v....s Spoil Banks mom. mi < bii igo Drainage Canal Inii iii re.eiit years the output has greatly diminished At present neither building stone nor flagstone i- being produced in the .loliet region. The present output of rock is used for concrete, agricultural limestone, road material, and ballast, and is routined to two quarries and the State Penitentiary. Regarding the future of the rock output in the Joliet region, Professor l> •' Fisher I lot. the amount of li I dimension si avail able is limited, and with the present tendency towards the use ol brick and artificial -lone, it seems fairly certain that the dimension stone industry of this ;,rv;. is not a growing in.lus- try. On the other hand the great abundance ol dol itesuit- I II / PHYSIOGRAPHY OF THE REGION OF CHICAGO able for mad metal, concrete aggregate, or for agricultural purposes, combined with its ready accessibility and the good transportation conditions, points to an increase for these pur- P s. 1 The quarry at Elmhurst, in I)u Page County, has a daily output of 1,000 tons, which is utilized for agricul- tural limestone, road material, concrete, and ballast. The Illinois State Geological Survey reports as fol- lows concerning Kankakee County: The overlying glacial drift is thinner on the average than in adjoining counties and nick is available at many places with only a thin cover of overburden. In the latter part of the 19th century large quantities of rock wen- quarried in the county for use as building stone, but the use of concrete for construc- tion purposes and the popularity of the Bedford stone are responsible for the abandonment of the building-stone indus- try in this county. Most of the abandoned quarries arc found in the vicinity of Momence and Kankakee. - The only quarries of any importance in the Wiscon- sin part of the region of Chicago are located (1) at Whitewater in Walworth County. (2) northwest of Ra- cine, (3) west of Burlington, and (4) at Ives in Racine County. The quarries of the last-mentioned town are by far the most important. A report issued by the Wisconsin Geological Survey (1914) states that here the supply of limestone is, "for practical purposes, un- limited." The quarry is equipped with a crusher with a capacity of about "2,(100 cubic yards per day, in 1912, making it one of the leading crushed-stone producers in the state. 3 The stone quarried at Whitewater is from the Galena-Trenton formation: though soft and earthy it is suitable for road material. Sand and gravel are abundant in the region of Chi- cago and in recent years have become of great economic importance in connection with building activities in Chicago and other cities and in connection with the building of the state and county systems of hard roads. In Waukegan fine gravels have been used in the manu- facture of roofing material. The greatest source of sand is the dune area of northern Indiana, from which whole trainloads are daily hauled away. Sand for local use is obtained from many other points on the Lake Plain, where the sand is fre- quently very pure; and from the few localities on the Kankakee sand plain where the sand is of good quality. Sand is also obtained in a number of places, as at Plain- field, through the screening of gravel, which may be as high as 75 per cent sand. The sources of gravel are chiefly two: ( 1 ) the beach ridges of the Lake Plain, and (2) the out wash areas a long the Illinois River and in the region to the north of that river. The beach ridges have been drawn on lo a con- Ibid., Hull. f,l. p. Ibid., Bull. 58, v Ibid., Bull. 16, p. 128. !•'. W. I Irak The Peal Re siderable extent chiefly for local Use. From the out wash areas the output of gravel has long been maintained on an important commercial scale: and vast reserves are available for the future. Most of the workings up lo the present time have been along the streams and rivers, where water for washing the gravel is easily obtained. The <: avel deposits occur chiefly along the Illinois. Des Plaines, I)u Page, and Fox rivers, and in out wash areas scattered through Kane. McIIenry. Walworth, Ken- osha, and Racine counties, often removed from any present-day streams. The glacial map and the general- ized soil map show most of the larger gravel areas: but there are innumerable small gravel pockets that are of considerable local importance. Such deposits occur in depressions on the moraine throughout the region, but are most abundant in the counties mentioned above. .Toliet ami Plainfield are important shipping centers for gravel. Clay. — By far the most of the clay products used in the region of Chicago are of local manufacture. The material used is chiefly the common glacial drift or "bowlder clay," which is obtained from selected areas where the content of pebbles and bowlders is low. With such a vast market for the finished products and such an inexhaustible supply of raw material, the region of Chi- cago has become a great center for the manufacture of clay products. Cook County ranks as the foremost brick-producing county in the United States, furnishing annually over half of the total output of the state of Illinois, which for many years has stood third among the states of the country in point of clay products, being exceeded only by Pennsylvania and Ohio. In northern Indiana there are available excellent lake clays in addi- tion to the bowlder clay: both kinds have long been utilized at Hobart. Porter, Chesterton, and other cities. Morris has for many years produced brick and tile made from lake clays occurring in the Morris Basin. In addi- tion to these clays, certain shales occur in the Pennsyl- vanian formations near Morris that are suitable for brick manufacture. In eastern Racine and Kenosha coun- ties there are lake clays that at one time formed the basis for a very important brick, tile, and pottery in- dustry, though today the output is relatively small.' Peat occurs in large quantities in various parts of the region, as is shown on the generalized soil map (Plate IV), but principally in McIIenry and Pake counties, Illinois, and in the three Wisconsin counties. The Wis- consin Geological Survey has made an exhaustive study of the peal resources of the state' and has reached the conclusion that little use will be found for peat until other fuel materials become scarce and expensive. The chief obstacle to the use of peat for fuel or gas is the high 1 Wisconsin Geological ami Natural History Survey, Hull. ..'J. p. 7£. i of Wisconsin, ibid., Hull. ',:, (Madison, L915). Pp. -27+. THE GEOLOGICAL RESOURCES <>!■' THE KIK.IOX can be recovered, and a large pail of this i- ash. The dried product is from eight to sixteen times as bulky as coal and has about one-half its beating value. The- peat areas, at present largely unused marshes, are therefore more likely to l><- drained and reclaimed for agricultural purposes than used for their potential fuel value. Coal. The Wilmington coal field extends into the southwest corner of the region of Chicago. While this Held was formerly a principal source of bituminous coal for Chicago, the larger pari of the production is mm shipped to points north and west. This is due to the high cost of operation in this field, as a result of which it is cheaper to ship coal into Chicago from Williamson County, 30 iles distant, than it is to -hip it in from Grundy County, only ■'>■'> miles distant. 1 This coal occurs in what is known as •'scam No. 2," which is here a wry widespread bed of uniform thick- ni'ss and character and lias been mined in scores of openings. It varies in thickness from 20 to 72 indies. Init shows much greater uniformity than these figures indicate, a variat ion of less than ."> inches throughout an entire mine being common. It is overlaid by a gray shaly sandstone 10 feet thick, and is underlaid by fire clay. Other coal seams, much thinner and I. ut little w orked, occur in t he field. Bowlders of glacial origin are frequent ly made use of for ornamental purposes: fireplaces, porches, stone walls, pedestals, and occasionally even for whole build- ings. Because of the variety of colors and patterns avail- able in these bowlders, most of which arc granites, very artistic and pleasing effects arc produced. WATER HI SOI RC] - : Springs having a permanent How are few. but there are numerous intermittent springs. l?oth types are usu- ally small and of local importance only. In Walworth County, Wisconsin, springs are abundant a Ion- tin t crop of the li i< I ml shale, there being many springs in the \ iciinty of Whitewater. The city water supply of Delavan is obtained from springs, and a well-known mineral spring, the Sheridan Mineral Sprint:, is located near Lake Geneva. 4 Drift wells constitute the most <• mon type of well and serve most of tin- farms and small towns. The depth to which such wells must be dug in order to obtain a constant water supply varies with the thickness and character of the material penetrated. Usually these wells are continued until they reach a stratum of sand or gravel; this will usually provide sufficient Bow. Often i Ittinoit Geological Survey, Bull. !■■. p iO I •' Ibid.. Bu Mui h ol tli«- < lii t :i f..r tins. s. , lion is taken fr,.m the following n eastern Ulinoit, ibid., Hull. .;; (Urbana, 1918 . Pp. Si8. ' Wisconsin Geological and Natural History Surrey, Bull. ■".. p. 590. it is found necessary to penetrate to the surface of the underlying limestone, or even into it. in which case the porous rock will usually afford an adequate supply of water. In general, wells of this shallow type are most successful on or adjacent to terminal moraines, ami in areas where sand ami gravel arc abundant. They arc commonhj from 8 to 5 feet in dii iter though some of the small towns have wells that arc up I . • -.'II feet m Si. PeJer- Sarsdslo Fig. 16. Outcrops of Potsdam and St. Peter sandstones in Wis- consin. These are the collecting areas for the artesian waters of the region of Chicago. (Reproduced by courtesj of the III Geological Survey. diameter. The majority do not exceed 20 30 feel in depth, but wells inn feet or more deep are not uncom- mon, especially in villages and on stock farms where a constant water supply is imperal ive. In t he areas of deep drift, as m Mcllcnry and Lake counties, wells are dug 200 feet in the drift. Shallow wells have two serious disadvanl they are subject to contamination and have frequently been found to be the cans.' of typhoid fever and other serious epidemics; and (2 they arc not absolutely re- liable, sometimes going drj or nearly so during periods of drought. For that reason deep wells of small bore thai are drilled into water bearing strata arc much to be preferred. K. ; .. pp. iss 89. ., Il,„t treatise Carl It. Anderson, 1 I fl Uu Sorth- PHYSIOGRAPHY OF THE REGION OF CHICAGO Drilled wells less than 500 feel in depth obtain their water chiefly from the uppermost rock strata, in most eases the Niagara limestone. They range from "200 to .".no feet in depth, average 850 feet, are usually drilled when only a comparatively small amount of water is required, and like the drift wells furnish water that is relatively soft, that is, free from lime. Because the lime- stone in this region is usually more or less fissured and sometimes porous, wells of this type ordinarily afford a dependable supply of water. Wells deeper than ,500 feet obtain their water chiefly from the St. Peter and the Potsdam sandstones. These formations are at the surface in Wisconsin, as indicated in Figure 16, and from that region they dip gently east- ward and southward so that in the region of Chicago thev lie hundreds of feet beneath the surface. Rain 150 feet of the surface. Thus the artesian water level here has dropped 230 feet. This is the result of the drill- ing of hundreds of deep wells which have partially exhausted the resources of the water-bearing strata. In outlying parts of the region of Chicago where fewer deep wells have been drilled, the level has dropped to a less extent or not at all. The depth to which artesian wells must be drilled varies with localities. In general, the necessary depth increases to the east on account of the eastward dip of the strata. ('. B. Anderson, of the Illinois Geological Survey, reports that in northeastern Illinois wells range in depth from .">()() to "2, 700 feet. The average depth amounts to between 1.000 and 1.800 feet for this portion of the state, being influenced by the large number of wells in Chicago and vicinity which are about 1,600 Collschnq Ore Fig. 17. — Artesian conditions. The upper water-bearing stratum corresponds to the St. Peter sandstone; the lower, ii' deep wells obtain water from both, the greatest quantity comes from the Potsdam. to the Potsdam. While which falls in Wisconsin on the outcrops of these porous formations is in part absorbed and. moving very slowly, descends through them toward the east and southeast to gradually increasing depths (sec Fig. 17). Subjected to the weight of the stream of water behind and con- fined between strata thai are relatively impervious, the water comes under greater and greater hydrostatic pres- sure or "head" as it is commonly called. When a stratum thus saturated with water under high pressure is tapped by a deep well, artesian conditions result; the water rises in the well to a height determined by the amount of head. Though this head may not be strong enough to make the well How. it al least will be sufficient lo make pumping easy. The amount of head has not remained constant in all parts of the region, but is in some places gradually decreasing. In 1H01 a well was drilled in Chicago to a depth of 711 feel, a relatively shallow depth, and enough head was encountered lo make the water rise lo a height SO feet above the surface. This particular well is now abandoned, but the oilier wells in its vicinity today penetrate to much greater depths, yet have such low head that the water rises only to within feet in depth. In the Stockyards at Chicago a number of wells have been drilled to depths greater than 2,200 feet and possibly over "2,500 feet; the deepest well, how- ever, is at Aurora and has a depth of "2.7.")!) feet. As the water level lowers, it becomes increasingly necessary to drill wells to the lowest strata. In Chicago, in recent years, the St. Peter sandstone has proved inadequate to furnish a sufficiently large flow of water, and wells have been continued to the Potsdam sandstone. The St. Peter is encountered at an average depth of SOI feet at Chicago: the Potsdam, at 1,400 feet. The water in the St. Peter and Potsdam formations is under pressure and hence is better able lo dissolve mineral substances than is the water occurring in the Niagara limestone and the drift. Consequently the water from the artesian wells is usually highly mineral- ized and hard. When the lowest part of the Potsdam is tapped, the water obtained is frequently loo sally for use. Wells in the Morris Basin that penetrate the Pennsylvania strata (Coal Measures) are sulphurous; this is also sometimes the case with water from the St. Peter. Such waters may have an offensive taste but are desirable for their medicinal properties. skli;ch:i) i;ip,ur state publications and. so far as they are -till in print, may be secured from the sources indicated for a nominal fee covering the cosl of printing. A few are available for free distribution. The majority of the publications listed are written in a style as free from technicalities as possible, and so arc of sen ice to all classes nf readers. Through reference to these works the reader may in many cases obtain detailed information concern ing particular localities or topics which especially interest him. ILLINOIS Cady, (i. II. Coal Resources of District I {Longwatt), Illinois G] N| BM Mining Investigations, ibid., Bull. /". Urbana, 1915. Pp. 1 19. Leverett, Frank. Pleistocene Features and Deposits of Hie Chi- Anderson , Car] 15. The Artesian Waters of Northeastern cago Area, Chicago Academy of Sciences, Butt. .'. Chicago, Illinois, ibid., Bull. Si. Urbana, 1919. Pp.326. Iv ' : |,,,sli - Krey, 1'.. and Lamar, J. E. Limesl R f Illinois. . 'I In Illinois Glacial Lobe, United States Geological Sur- ;/,;,/ / :il /j , t - (,.|, .,,,., mas p D 30a vey, Mmn.,,. AS. Washington, lsii!t. Pp. 817. Alden, William C. Chicago Folio, ibid., Folio 81. Washington, soil poblk itions 1902. Pp. If. SoilReport and Map (issued for Illinois bj the Bureau of Soils, At» I, Wallace W„ and Goldthwait, Ji sWalter. Physical U.S. Dept. of Agriculture, Washington): Witt < Geography of thi Evanston-Waukegan Region, Illinois Soil reports and maps (issued by the Soil Survey, I aiversitj Geological Survey, Bull. 7. Urbana, 1908. Pp. 102. oflllinois Agricultural Experimenl Station, Urbana, til.): Goldthwait, James Walter. Physical Features of the Des Report Plaines Valley, ibid.. Bull. II. Urbana, 1909. Pp. 103. '■'■ LakeCounty 1815 Trowbridge, Arthur C. Geology and Geography of the Wheaton ls - Kankakee Countj 1916 Quadrangle, ibid., Bull. 19. Urbana, 1912. Pp. 79. Hi - "" Page County 1917 SauJT, Carl (). Geography of th Upper Illinois Valley, ibid., IT KaneCount > l! "' a 11 ,■ rik .„.,■ i» •no -'' McHenrj Countj 1921 Hull. .',. 1 rbana, !!•]<.. Pp.208. . , , e_r 1 01, 1 til ivir /■ (•/ , ; t -2... I.ivmi^>I on < ..initx III-.': Salisbury, II. !>.. and Alden, William ( . Thi Geography of .,,, Grundy County ,„., ( hicago and Its Environs (rev. ed.), Geographic Society oj Will County (ma| K to date Chicago, Bull. I. Chicago, 1920. Pp. <;:s. ,, , | .. .. .,., . , . ,,, .... .,, ,. Uso see Summary of Illinois Soil Investigations, University of .. . .. .... . , ... .,, ' ,, Illinois Agricultural Experiment Station, Bull. 193. Lulver, Harold h. Geology and Mineral Resources of the Morns .-, , .,.. . Quadrangle, Illinois Geological Survey, Bull. ','■. I rbana, [NDIANA 192 I pp 95 804. Fisher, D. J. Geology and Mineral Resources of the Joliet Quadrangle, ibid.. Bull. 51. Urbana, 1925. Pp. 160. Blatchley, W. S. "The Geology of Lake and Po> - ( le. J.Paul. Thi ' rraphic Background of Chicago. Chi- / "'"' ""'' , """" / /;,/ ""' / (DeDt "' Geo,0 » ■""' ,, ,q |. - Il() Natural Resources, Ind.), pp. 25 105. Indianapolis, 189* Leverett, Frank. "The Water Resources of Illinois, " Seven /unlit Annual Report (U.S. Geological Survej I, pp. ",i<\ 842 Washington, ls:»i. Alden, William C. Thi Stone Industry in tin Vicinity of Chi- lllinois. United Stales Geological Sunn/. Bull. .'/■•'. pp. .;.-.: 60. Washington, 1902. Burchard, E. F, ConcreU Materials Produced in tin Chicago District, Illinois Geological Survey, Bull. 8, \>\>. 346 72. I rbana, 1907, Bement, A. Tht Illinois Coal Field, ibid.. Bull. 16, pp. 182 208. I rbana, 1810. See foregoing refer* ocea also. Blatchle) .U.S. 'The < Ilaj s and • Ilaj Indusl riesof I udiana." Twenty-ninth Annual Report Depl ol Geology and Natural Re rces, Ind.), pp. 13 657. Indianap "The Road Materials of Indiana." Thirtieth Annual Report (Dept. of Geolog} and Natural Resources, Ind. . pp. 161 275. Indianapolis, IS Taylor. A. E. "On the Peal Deposits ol Northern Indiana," Thirty-first Annual Report Dept. of Geology and Natural Res C( - Ind pp 73 208 Indianapolis, 1900. Leverett, Frank, and Taylor, 1 B f Indiana iiml ilu History of tht Great I ' Survey, Monog. 58. Washington 1915 Pp PHYSIOGRAPHY OF THE REGION OF CHICAGO Logan, Cumings, Malott, Visher, Tucker, and Reeves. Hand- book of Indiana Geology, Division of Geology, Indiana Department of Conservation, Pub. 21. Indianapolis, 1922. Pp. 1120. SOIIi l'l m.ic WIONS Quin,E.J. "SoilSurvej of La Porte, St. Joseph and Bartholo- mew Counties," Thirty-sixth Annual Report (Dept. of Ge- ology and Natural Resources, Ind.), pp. 281-334. Indian- apolis. 1911. County soil reports and maps (issued for Indiana by the Bureau of Soils. I'.S. Dept. of Agriculture, Washington): Newton County 1906 Starke County 1917 Porter County 1918 Lake County 19-21 WISCONSIN Chamberlin, T. C. "Geology of Eastern Wisconsin," Geology of Wisconsin, XI. 93-405. Madison: Wisconsin Geolog- ical Survey. 1877. Fenneman, N. M. Lakes of Southeastern Wisconsin. Wisconsin Geological and Natural History Survey, Bull. 8. Madison. 1902. Pp. 178. Alden. William C. The Delavan Lobe of the Lake Michigan Glacier, United States Geological Survey, Prof. Pap. 34. Washington, 1904. Pp. 106. Ries, Heinrich. The Clays of Wisconsin and Their Uses, Wis- consin Geological and Xatural History Survey, Bull. 15. Madison, 1906. Pp. 247. Case, E. C. Wisconsin, Its Geology and Physical Geography. Milwaukee, 1007. Pp. 190. Goldthwait, .lames Walter. The Abandoned Shore-Lines of Pastern Wisconsin. Wisconsin Geological and Xatural History Survey, Bull. 17. Madison. 1007. Pp. 134. Martin, Lawrence. The Physical Geography of Wisconsin, ibid.. Bull. 36. Madison. 1007. Pp. 134. Alden. William C. The Quaternary Geology of Southeastern Wisconsin. United States Geological Survey, Prof. Pa/i. 106, Washington. 1018. Pp. 356. Whitbeck, R. II. The Geography and Economic Development of Southeaster// Wisconsin, Wisconsin Geological and Xatural History Surrey. Hull. 58. Madison. 1921. Pp. tot. ECONOMIC Hotchkiss, W. (>.. and Steidtmann. E. Limestone Road Ma- terials of Wisconsin. Wisconsin Geological and Xatural History Surrey. Hull. ■!',. Madison. 1914. Pp. I.'i7. Huels, F. W. The Peat Resources of Wisconsin, ibid., Hull. 45, Madison, 101.5. Pp. -»74. Weidman. S.. and Schultz, A. R. The Underground and Sur- face Water Supplies of Wisconsin, ibid., Hull. 35. Madi- son, 101.3. Pp. Mil. SOIL PUBLICATIONS County soil reports and maps (issued for Wisconsin by the Bureau of Soils, U.S. Dept. of Agriculture. Washington I : Kenosha and Racine counties 1922 Walworth County 1924 County soil reports and maps (issued by the Wisconsin Geological and Natural History Survey. Madison): Hull. 56B, "Soil Series No. 29" Racine and Kenosha counties Bull. 56C, "Soil Series No. 80" Walworth County INDEX Acknowledgments, v Agricultural Experiment Station, University of Illinois, v, 48 Alden, William C. v, 13, 39 Alexandrian series, 37 Uton, 17 American Society for Testing Materials, 37 Anderson, Carl B., 4'J. 50 Animal life of dune region, 35 36 Arlington Heights, ll Armington, 1. II . 9 Art, •,.an wells, 19 50 Atchison, Topeka, \ Santa IV Railroad, 21 Athy. L. r.. 7 Aurora. It Aurora Plain, 28, 29, 11 An\ Sable Creek, 19, m Bailey, E. S-, 34 Barrett, Edward, 34 Barrington, W Batavia, 28 Beach ridgea and bars, 18, IS, l> Bed rock, I, 37 11, n is. 50 Beecher. I] Bell* I, 17 Bensenville, II Benton Harbor, SO Beverlj Hills, n Bibliography: general, ■">" 51; • >,, dunes, 34; on vegetation, 7 Mini life of dune region, 35 .!(> Bloomingdale, ti Bloomington moraine, 28 Blue Island, II Blue Island Ridge, II Bowlder clay, 12, 18 Bowlders, use of, 19 Brandon's Bridge, \'-> lint/. J II.. v Bridgeport, 10 Bureau of Soils, I ,S. Dept. of Agriculture, v. Burlington, W, H, is Bums's ditch, ll 15, 83 Bumside, 3 I Calumet River, I:! I".. It;. 19 < lalumel >t. ,>.■,■. Lake ' In. _ Canals, i I i 5 80 81 Carbondale form.,' < edai I a Cement, 17 Central Lowland, I Chamberlin, T. C, v, 82 ( li.inn.ili..,,. 19 < hesterton, 16, 18 Ui.iM Railroad, .'l i hicago artesian wells in, 50; bed r.nk nn- der. Hi; climate of, !» 10; drainage in, 1 1 15; limestone produce of, 17: quarries in, Chicago, Commonwealth Club, v Chicago Drainage Canal, IS, 15, is 21,31, 17 < 'hicago harbor, !•, 13 Chicago Heights, 24, II Chicago outlet, 7. 12, is 21, 22, 25, 26, IS, 14, 15, 17; depth of bed rock in, 10 Chicago Plain, 11, 12, 39, IS Chicago region, definition of, \ ( 'hicago Kcyiiuuil Planum..' Vssoi-ialion. work Of, v Chicago River, 12, IS, 15, 16, is. 19, -i« Clay, 12, 13, is Climate, 9 10 Coal. 37, S9, 19 ( 'oal Basin, Eastern Interior. :S7 Coal Measures, :t7. 38, 39, 50 < lobble beaches, 32 < oburg, 11 Committee on General Survey. Chicago Regional Planning Association, \ Concrete, 17 is Continental Divide, I. 15, 21, 22 it. '.'."> Cook County, v, 22, 11, 17. 18; foresl pre- serves of, 17. 23, .'l Cooley, L. E., 1!> Comiferous formation, 39 Cowles, II. C, v, 7. 9, 34, 35 ( ox, II. C, 9 Crown Point, 23, 11 Dairying, 17. -U Day, P. i 30 Delavan, 19 Delavan lobe of glacier, 5, 7. 22, 23 Deposition along shore of Lake Michigan, 7. II. 12, Depth of bed-rock surface, 39 11 Des Plaines, 16 Des Plaines River, 7. 13, 16, is 19, 83 15, is Des Plaines Valley, rock outcrops along, W, 17 Devonian Btrata, 8, 5 17 18, 39 Diversion of water al < 'hicago, 81 I >ow ners ( irove, 24, n Downing, Elliol R., 35 Dune Park, 16, 36 Dunes of Kankakee Basin, 26 I i Dunes ,,f Northern Indiana, 7, 9, II :i 16, is D ■ sail, I. 14, 15, 16, is DuP I ui tj -. 84, 41, 15, 17. is I r, is, 19, 85, is Drainage and Water Suppl) Commission of ' go, 19 Dresden Heights, 19, 88 Dnftles, area, shown on diagrams, i'\ 7 Bdgewood formation, 37 Bkblaw, i.l Elburn, 28 Elgin, •-'■-'. 25, 28, i!). 41, 47 Klinliurst. II. 17. is Engineering Board of Review of the Sanitan District of Chicago, 31 Erie lol f glacier, <; Erosion along shore of Lake Michigan 7 16 :il S3, :si Evanston, i 1 Fairchild, Herman I... 30 I'ellli, inan. \. M., 1. i Fertilizer, 17 Fisher, I). J., v. 39, 17 Flagstone, 17 Fluctuations in level of Lake Michigan :;u Flux, 17 Forest preserves: of Cook County, 17,23,24; of Dil Page County. -.'I; of Kane County. il Fort Shi M. I. m i; 13 Fort Wayne, 2] Fox Lake, 83 Fox River, 19, 23, 28 29, II, 15, is Fox River Valley, rock outcrops along, 17 Franklin Park, il Puller. George I).. \ . 7 Galena formation. 37, is Galen Creek. 23 Gary, 11. 15, 33, 34 Geographic Society of Chicago, 12 Geologic form. iti, ins Geologic History, I 7 1 ieological resoun es, 17 50 Georgian Baj . ii (ilaeial drift, 12, Is ( llaciation, 2 9 Glencoe, 17, 32 Glen Haven, .limes near. :!l Glenview, 84 Glenw I stage, Lake < !hii ago, l .' Goldwait, .1. W., v. is. |9 G le. .1 Paul, v Grand Haven, 30 (.rani Park. 12 Gravel, is. 12, ts Grays Lake. 23 (.re.it Lakes rei; (,'eoloeie featllr. Greal Likes III,, Waterway, 21 ( ireeli Baj . li (irun.l.v County, Ham, id, 15, S3, 10 M II e, 40 Hebron, II II - !,. I.", 54 PHYSIOGRAPHY OF THE REGION OF CHICAGO Hennepin, 19 Heuls, F. W„ is Highland Park. IS, 16, IT. 40 Highw I. 11 Hobart, hi. is Hodgkins, 17 Homewood, 21 Hudson Lake, 23 Illinois Centra] Railroad, 22, 17 Illinois Geological Survey, v, IT. is [llinois-Michigan Canal, is 21 Illinois Biver, ii. T. 13, is. L9 21, 24, 26, 28, 29, Hi. II. is Illinois State Board of Health, Report of, 1!) [ndiana Department ,,f < "< >n-n-r\-;tt ii>n. .'Hi [ndiana Department uf ( i«-< >1< >^\ and Natural Resources, v [ndiana Harbor, !i Indians, use nf Chicago nutlet by, 1!». '21 Iroquois River. 26, 2!) Itaska, 41 Ivan! , +n Ives. 40, 47, 18 Joliet, 18, 19. 21, 25, 37, 39, 40, 12, tT Joliet, Louis. 21 Juliet stone industry of, 47-48 Jones, W. I)., v Kane County, v. 24, 28, 37, 41, 45, 47, ts Kankakee, 25, 41, 48 Kankakee Basin, 26 27, 45 Kankakee County, v. 27, (5 Kankakee formation, 37 Kankakee marsh. 26 27 Kankakee River, (i. 19, 23, 25, 26 27, 29, 15 Kankakee Sand plain. ti-T, 26-27, 16, 4S Kankakee torrent. 7, 2.3 Kankakee Valley Drainage Company, '20 Kansan epoch of glaciation, 2 Lake Mil bigan, 30 31 Lake Michigan, changes in level of. 311 31 Lake Michigan Basin: formation of. 5 T: de- si ription of, SO 31 Lake Michigan lol f glacier. 5, 6, 7, 16, 22, 23 Lake Michigan terrace soils. 4.3 Lake Morris (i. 26 Lake Ontario, 6, 31 Lake Plain, 1. 1 1 15, 16, is. 22, 24, 32, 12, 1:'.. 15, Hi. 4S; depth of bed rock on, 10 Lake region: of Illinois, 22 23; of In, liana, •23; of southeastern Wisconsin, 22 23 Lake Superior, 31 Lake Zurich, 23, 10 Lamar. .1. E., tT Lane's Island, is Laporte, 22, 23, 41 Li te County, 15, 22. 23, 2T La Salle. 20 LcighloTi. M. M.. v. 25 Lemont. 18, 40. 41, IT Levels of Great Lakes. 30-31 Leverett, Frank, v, 26, 28, 32. 39, 40, 41 Limestone. 47-48 Lincoln Park. 33, 40 Loekport, 20, 41 Loess. 42. 43 Long Lake. •iS Lowell, 25 Ludington, dunes near, 34 Lyons, HI. 47 Mae( lintock, Paul, v MeCook. IT McHenry County, v, 22, 23, 43. 4(i. 48, 4!) McLeansboro formal ion, 39 Manhattan, moraine. '2.3 Mantcno. 25, 41 Manteno Plain, I. 18, 22, 25, 26, 46; depth of 26 27, 28,39, Hi. H, ivausan coot u oi giaciauoil, i. Kendall County, V, 37 bed rock on, 41 Kenosha, 11. 12, 32, 34, 4(1 Marengo moraine, 28 Kenosha County, is, 23, 40. 44, 43 Marquette, 19 Kiev. F„ IT Marseilles, 6 Marseilles moraine. i Sag I nannel, 14, 15, is. 21, i:i Saginan lol f glacier, <> St. An.,.-, -'s. 29, H >l. John, Former village of. :i:i St Peter formation, ::7. Hi. 50 Salisbury, R. 1>.. v Sali Creek, is Sand, ii. 26 27, 12, 14, 15, Hi. ts Sand plain of Kankakee Basin, 6 7. 26 -'7. 4(1. ts Sanitary District >>t ( hicago, 19, 31 Sawyer, dunes near, :'•! Schantx, i». M., 34, Si Schaumberg, n Seiches of Lake Michigan, 30 SI, am... ii. C. \V., :ll Shelbj ville, 8 Sheridan Mineral Spring, Hi >l...r.'.|nft. :iJ Shore In..- ..f Lake Michigan II 16 Silurian strata, .' Silver Lai Sk.iki.- marsh, 16 Ml. III.. I.. II.. V Mill!). U. S . \ Soils 7 |; v. South Bend, 26 South Chicago, !> II. 14, 15 Spoil banks, 17 Spring Prairie, 11 Springs, 4U Starke Count] v, 27 Starved Rock, 37 Stockyards, ».-ll at, 50 Stony Man. I, 1 1 1 2, m Sturgeon May. :lu Summit. I:!. IS. III. HI. 17 Surface material-. I.' Hi Surface of bed rock, ;i!> 1 1 Taylor, P. B., v Terraces in ( Ihicag itlet, is Thornton, 10, 17 Tides in Lake Michigan, 30 Till, glacial, 12 Tolleston stage, Lake Chicago, 12 Topography of bed rook. :!!> Trail Creek, Hi. 23 Union (.r,.\c. Hi I iiit.-.l Stat.-- Department of Vgr Bureau of Soils, \. 13 United Stat.- Geological Survey, v United States Lake Survey, v, :!ii University of I hii a) o University of Chicago, Committee i ( 'ommunity Research, v Valparaiso, 22, 23, M \ alparaiso moraine, 22 Valparaiso Upland, 1,6, Hi. [8,21,25 .'.i t:. Hi: depth of bed rock on, I Vegetation, 7 <• Wabash Railroad, 25 Walworth County, 82, 1 1 10, ts. hi Washington Park, S3 \\ atei resources, Hi .">u Wauconda, Hi Waukegan, 7, 9, 1 1. I-.'. Hi. is Weather, 9 Hi Wells. HI .-.ii Wesl < 'hicago, -'.s Westerfield, < '. P., 33 Wheaton, -'I Wheeler, II Whitewater, is. hi Will County, 22, II Williams Bay, 22 Williamson County, Hi Willow Spring. 20 Wilmetti Wilmington, 25, .17. hi Wind Lake, 23 w, I II Winnetka, 7. II. IS, 16, 17. 3 I 10 Wisconsin epoch of u'laoialion. .'. Ii Wisconsin Geological and Natural lli>t..r Survej . \ . is Wisconsin Soil Sun i I Wolf Lake, 15, 33 W Kill,-. II Worth, is Yellow River, 26 Yorkville, 88 rp»iNT[[>"| l ' IOX; " ''"'- '■'"" ■■'■■ '■■' !■'■ ITI'BFS Ol Tl.t RSOION 01 ('mica , p M |m..,!i Hi. -'4 mi t| u - rr-pi-.rl-, of ilic I > (,...|..^,^,l Survey and of t UNIVERSITY OF ILLINOIS-URBANA 3 0112 074714921