USA > Illinois > Atlas of the State of Illinois, to which are added various general maps, history, statistics and illustrations > Part 15
Note: The text from this book was generated using artificial intelligence so there may be some errors. The full pages can be found on Archive.org (link on the Part 1 page).
Part 1 | Part 2 | Part 3 | Part 4 | Part 5 | Part 6 | Part 7 | Part 8 | Part 9 | Part 10 | Part 11 | Part 12 | Part 13 | Part 14 | Part 15 | Part 16 | Part 17 | Part 18 | Part 19 | Part 20 | Part 21 | Part 22 | Part 23 | Part 24 | Part 25 | Part 26 | Part 27 | Part 28 | Part 29 | Part 30 | Part 31 | Part 32 | Part 33 | Part 34 | Part 35 | Part 36 | Part 37 | Part 38 | Part 39 | Part 40 | Part 41 | Part 42 | Part 43 | Part 44 | Part 45 | Part 46 | Part 47 | Part 48 | Part 49 | Part 50 | Part 51 | Part 52 | Part 53 | Part 54 | Part 55 | Part 56 | Part 57 | Part 58 | Part 59 | Part 60 | Part 61 | Part 62 | Part 63 | Part 64 | Part 65 | Part 66 | Part 67 | Part 68 | Part 69 | Part 70 | Part 71 | Part 72 | Part 73 | Part 74
RAIN-FALL .- In comparing the East and the West in respect to the annual amount of rain, we find this difference: That whilo in the former region it is pretty equally distributed over the four seasons, in the latter it is unequally distributed ; spring and summer heing the wot season, and full and winter tho dry scasou. This will be apparent when we contrast the rain-fall at three stations occupying about the same
latitude, but extending through nearly twenty degrees of longitude,
Spring.
Summer.
Autumn.
Winter
Year.
Washington.
10.4
St. Louis ...
12.30
10.52 14.1 7.1
10.10 8.01
11.07
41.20
42.32
Fort Riley.
7.91
5.68
1.20
21.90
While there is a rapid diminution in the yearly amount of rain as we leave the Mississippi River and penetrate to the Plains, we find that in the latter region, during the growing season, nearly three-fourths of the yearly precipitation takes place. These are conditions highly favorable to the growth of grasses, hut detrimental to the growth of trees, and henee it is we have on the seaboard luxuriant forests and in the interior grassy plaius. Illinois occupies a geographical position where these great elimatic changes begin to manifest themselves, and where the distinctive features of the prairie first become fully apparent.
Meteorological observations have not been made in this State at a sufficient number of points, nor do they extend over a sufficient period of time, to enable us to trace out all the vary- ing conditions of moisture ; but this general law is recognized : The greatest yearly precipitation (fifty inches) oceurs in the extreme southern part of the State, and it gradually diminishes as we procced northward, until, in the northern part of the State, the precipitation amounts to only thirty six inches. But there is another element not to be overlooked. There is a dif- ference between the two sections of ten degrees in the annual temperature, and therefore the amount of water taken up by evaporation is considerably greater in the southern extremity of the State than in the northern. Owing to the paucity of obser- vations, we have to take those at St. Louis as indieative of the climate of the southern part of the State, in the latitude of Alton. As in proceeding westward and northwestward, the amount of precipitation becomes diminished and more unequally distributed over the four seasons, the changes in the vegetation become more marked. Even in Illinois tbis chauge is observed, the southern portion of the State heing well wooded, wbile in the central and northern portions, the country stretches out into vast grassy plains.
Illinois is situated in the zone of southwest winds, but ohserva- tions would indicate that there are abnormal conditions which change their general flow. It is believed that the northeast Trades entering the Gulf of Mexico are deflected in their course by the lofty chain of the Andes, when they become inward breezes on the coast of Texas, southerly winds in the Lower Valley of the Mississippi, and southwesterly as they reach the Upper Valley. It is to this acrial current that we owe our hot and moist summers. The north and northwest winds, which set in with the change of the season, depress the temperature below that of the Atlantic slope, and at the same time are attended with a diminished precipitation
DISTRIBUTION OF HEAT .- It would seem that, in the spring, the warm hreatlı of the Gulf flows up the Valley of the Mississippi, communicating to vegetation a quiekening power which is sooner felt than on the seaboard. On the other hand, the Aretie winds, during the winter, with no great har- rier to arrest their course, flow down toward the Gulf, and depress the lines of temperature below those of places in the salue latitude on the seaboard. Thus it may be said that the elimate of Illinois is in a more marked degree continental than that of the Atlantic slope. St. Paul, Minnesota, although more than two and one-half degrees further north than Boston, and seven hundred and seventy feet greater in altitude, has a little higher spring and summer temperature than Boston, while its fall aud winter temperature is cighteen degrees lower. Lake Michigan undoubtedly modifies the temperature at Chicago, mitigating the summer heats and the winter colds. This is scen in the comparison of the temperature, hy seasons, between Chieago and Ottawa or Rock Island. Comparing, therefore, the temperature of Ottawa with that of Boston, the latter being one degree of latitude further north, hut five hundred and seventy feet depressed helow Ottawa, we find the springs and summers at the former place are ahout five degrees warmer, while the winters are three degrees and five minutes eolder.
With regard to the temperature of the southern part of the State-and here we confess we have not a connected series of observations made at various stations to guide us-it would appear, at all seasons, to be about that of the seaboard regions in corresponding latitudes. St. Louis is a little warmer in the
173
spring and summer, with ahout the same fall and wiuter tem- perature as Washington. These comparisons will be obvious by reference to the subrjoined
TABLE OF TEMPERATURES.
STATIONS.
Spring. Sum'r. Ant'm. Whiter
Lut
Long.
Alt
Boston ...
40 3
09.1
51.0
48.0
46.7
41 52
87 95
591
Chicago ..
419
17.3
53
5212
21.8
50.5
41 20
85 47
020
Rock Island ..
St. Paul.
$5.6
70.6
10.1
44.6
44 63
93 10
St. Lnk.
50.4
76,3
73.1
533.0
93.9
53.8
38 53
77 01
Washington
GEOLOGY.
BY A. H. WORTHEN, STATE GEOLOGIST.
But little was known in regard to the geological structure and resources of this State anterior to the organization of the Geological Survey in 1851. Previous to that time, some local examinations had been made along tho Ohio and Mississippi Rivers, by Prof. Hall, of New York, and Dr. David Dale Owen, of New Harmony, Indiana ; but by far tbo greater por- tion of the State remained unexplored.
Before the publication of his final report on the Fourth Dis- trict of New York, which appeared in 1843, Prof. Hall made a tour through some of the Western States, as far west as St. Louis, for the purpose, as he states, of identifying the rocks and groups of New York with those to which different nanies had been given hy Western geologists. His report on that tour of exploration is given iu Chapter XXIII of that vol- ume, and it appears from that that he recognized tho lime- stones outcropping on the northern shore of the Obio River, in Indiaua, below Louisville, and between the mouth of the Wahash aud Cairo, in Illinois, as of Lower Carboniferous age, and applied the term "Subcarboniferous limestone" to them, as indicating their position below the eoal-bearing strata. Af- ter leaving the mouth of the Ohio, he says: " After ascending the Mississippi for some distance, the rock again appears. The great valley of the American Bottom is bounded on either side by abrupt cliffs of this (Subcarhoniferous) limestone; the river, meandering in its course from side to side, sometimes runs at the base of tbe perpendicular rock, while the opposite side presents a broad, level hottom-land, covered, for tho most part, with luxuriant forests of primeval growth. These cliffs form some of the most pieturesquo seenery, and, with the small shot towers upon the overhanging margin above, suggest the idea of stupendous castle walls of cyelopean architecture, crowned with the sentinel's towers. Between the point of its first appearance on the Mississippi and its final disappearanco near the mouth of Rock River, I examined it at numerous poiuts, and always found a very uniform lithologieal character, which alone is sufficient to distinguish it from all other rocks, and enable one to identify it with its commencement in Indiana." From what we have quoted, it will be seen that Prof. Hall considered all the limestones exposed along the Mississippi, from the mouth of the Ohio to Rock Island, as identical with the limestones on the Ohio below Louisville, which he termed "Subearboniferous." It is now well known, however, that the whole paleozoie series from the coal measures to the Trenton limestone is two or three times repeated in the exposures along the bluffs of the Mississippi, between St. Louis and the mouth of the Ohio, and that between St. Louis and Keokuk we have outcrops also of all the formations from the eoal measures to the St. Peter's Sandstone, inclusive. Extend- ing his examinations northward to Galena and Dubuque, Prof. Hall included the Devonian limestones of Rock Island and vicinity, in his Suhcarboniferous formation, but recognized the magnesiau limestone above Roek Island as the equivalent of the "Cliff limestone," of Ohio. The lead-hearing lime- stone of Galena and Dubuque, however, and the blue lime- stoue below it, were also referred by him to the same forma- tion, the Cliff limestone.
In Dr. David Dale Owen's report on the Geological Survey of Wiscousin, Iowa and Minnesota, published in 1852, ho divided the Subcarboniferous limestones into four distinct groups, which are now generally recegnized, although tho distinetive names he assigned to them have not been retained. He also recognized the limestones of Rock Island as Devonian, aud
STATE GEOLOGY.
separated tho limestones of the Northwest into Upper and Lower Silurian, thus placing them in tbo horizon to which they properly belong.
The Geological Survey of Illinois was commenced in 185I, under the direction of Dr. J. G. Norwood, of Madison, Indiana, and, in 1857, ho publisbed a pamphlet report of ahout one hundred pages, eutitled an " Abstract of a Report on Illinois Coals, and a General Notice of the Coal Fields," accompanied by a small map of the State, on which the general outlines of the eoal measures, as well as some of the older formations, were defined. HIe made no attempt, however, to separate the Lower Carboniferous limestono into groups, but recognized the oecur- rence of the Conglomerato or "mill-stone grit" between the limestones and the true coal measures. Ho also recognized the occurrence of the Devonian and Silurian systems in the State, but made no attempt to separate them into distinct groups. He also noted the occurrence of Tertiary beds in tho extreme southern portion of the State. This report contains analyses of most of our coals and limestones, as well as firo elays, iron ores and other minerals collected iu the proseeutiou of the sur- vey.
While this work was in charge of Dr. Norwood, the writer was employed, for about three years, as Assistant Geologist in the survey, aud during that time worked out with considerable care the subdivisions of the Lower Carboniferous as well as of the Devonian aud Silurian systems, as they were developed in that portion of the State in which he was employed. These results were duly placed in the hands of the chief of the sur- vey, but were never published. Subsequently, in 1854, the writer of these remarks engaged in the Iowa survey, then in charge of Prof. Hall, to whom was communicated the results of his investigations in Illinois, and they were published in the report on the Geology of Iowa, which appeared in 1858. In this report, tbo Chester division of the Lower Carboniferous limestone, under the name of Kaskaskia limestone, was added to the divisions previously made by Dr. Owen, though it is but justiee to the latter to say that he recognized this group as distinct from other divisions of the Lower Carboniferous formation, but plaeed it in the Millstone Grit, as a division of that rather than of the limestone series.
In Mareli, 1858, tho writer was commissioned as Geologist in Chief of the Illinois Geological Survey, and, in 1866, Vols. I and 2 of his report were publisbed, and two years later, in I868, the 3d volume made its appearanee. Tbe synopsis of the geology of the State, which is here given, is taken sub- stantially from these volumes. In the first volume of tbe report, the "Kinderbook group was added to the Lower Car- boniferous series, having previously been placed by Prof. Hall, in the Iowa report, in the Devouian system, under the name of Chemung group, on the supposition that it was the western equivalent of the Chemung beds of New York. It is now. however, conceded by all Western geologists, that its true posi- tion is at the base of tho Lower Carboniferous series through- out the Western States.
The geological structure of Illinois embraces, as has been shown in the volumes already published, a representation more or less complete of the whole paleozoie series of formations, from the Caleiferous group of the Lower Silurian, to the top of the coal measures, or the Permo-carhoniferous of Meek aud Hay- den. In addition to these older rocks, we find a limited arca covered with Tertiary deposits in the extreme southern portiou of the State, representing the northern boundary of tho great Tertiary basin of the more southern States; and overspreading these formations, and resting uneonformably upon them all, we find beds of moro receut age, comprising sauds, clays and gravel, of variable thiekness, ranging from ten to more than two hundred feet in the aggregate, covering up the older form- ations everywhere, except among the rivers and smaller streams, where they have been carried away by erosive agencies. These superficial deposits may be divided into Alluvium, Loess and Drift, and constitute tbe Quaternary systeru of modern gcolo- gists.
SILURIAN SYSTEM-LOWER.
CALCIFEROUS GROUP .- This group comprises the St. Peter's Sandstone, and the Lower Magnesiau limestone of Dr. Owen. The latter is only partially exposed in this State, and outcrops only at a single locality in La Salle County, extending for
* This Dame was proposed by Meok and Worthen for this group, in a paper published in the American Journal of Science, Vol. XxxII, No. 05, for September, 1801.
about two miles along the valley of the Illinois River in the vicinity of Utica. The thickness of the strata appearing above the surface here is only about eighty fect, and they consist of alternations of thin bands of Magnesian limestone with layers of Calciferous sandstone, the strata seldom reaching a foot in thickness. Many of the limestone layers possess hydraulic properties, and about the middle of tho bed there is ahout six feet in contiguous strata of good hydraulie rock, from which Mr. James Clark & Son manufacture annually about sixty thousand barrels of cement. Some of the thiekest strata are used for building stono, but they are generally too thin to he valuable for this purpose. The entire thickness of this rock below the surface has not been ascertained, but the boring at Ottawa for oil, if correctly reported, would make it about four hundred feet.
The St. Peter's Sandstone, which immediately overlics the Magnesian limestone above described, outcrops in the valley of the Illinois River, forming the main portion of the river bluffs from Utica to a point beyond Ottawa, and, according to the observations of Capt. Freeman, wbo made the detailed survey of La Sallo County, it forms the " bed rock" over most of the two northern ranges of townships in this county. It also out- crops on Rock River, between Grand Detour and Oregon City, and in Calhoun County, on the Mississippi River, it forms a conspienous bluff, named by the early French navigators " Cap au Gres." Its maximum thickness in this State may be estimated at ahont two hundred feet. Usually it is too incoberent in its texture to be of any value as a building stone, though at Cap au Gres the lower portion of tho mass hardens on exposure by the oxidation of the iron which it contains, forming a perpendicular eliff along its outerop, and might, probably, be safely used for foundation walls, ete. In the vicinity of Dixon, in Lee County, some of the upper strata appear to be slightly calcareous, and have been used for caps and sills in some of the best hnildings in the city, and appears to be a durable stono. Its principal value, however, consists in the inexhaustible supply of the finest sand for tho manu- facture of glass, which it affords. Several glass factories have already been established in La Salle County, and the business may bo increased to any desirable extent. In Missouri this formation has received the name of Saechnroidal Sandstone, from its white, granular and pulverulent eharacter, and has been largely exported to Pittsburgh for the use of tho glass factories there. No fossils sufficiently distinct for deter- mination havo been found, either in this sandstone or in the magnesian beds below it in this State.
TRENTON GROUP .- This group, which immediately overlies the St. Peter's Sundstoue, consists of three divisions. The first, or lowest, is a brown magnesian limestone or dolomite, usually in regular beds or strata, varying from four inches to two feet or more in thickness. In tho northern portion of the State, we have not wiet with this division where it exceeded an aggregate thickness of about twenty feet, but at Cap au Gres, in Calhoun County, where it forms the upper part of the bluff, overlying the St. Peter's Sandstone, it is from sixty to seventy feet in thiekness. This is, probably, the "First Magnesian Limestono " of the Missouri reports. At the quarries near Homer, in La Salle County, it abounds in fossils, among which aro a large Lituites like the L. undatus from the Trenton group in New York, several species of Orthoceras, Ma- clureu, etc.
The middle division of this group consists of light gray com- pact limestones in the southern and western parts of the State, and of light blue, thin bedded, sbaly limestones in the northern portion, except in the vicinity of Galena, where the magnesian beds above described are not developed, and the blue lime- stoues form the lowest portion of the group. Tho upper di- vision is the well known Galena limestone, the lead-bearing rock of the Northwest, and hence its nanie, from the galena or sulphuret of lead which it afforded. It may he described as a buff-colored, porous dolomite, sometimes arenaeeous and uu- evenly textured, and wlien decomposed it gives origin to a fer- ruginous, sandy clay. It is usually rather evenly bedded, but locally presents a eoneretionary or breeciated oharaeter, and, from its peculiar texture, it weathers very unevenly, and hence the bluffs, when composed of this rock, present a variety of picturesque forms, often imitating the ruined towers and bat- tlements of an ancient castle. All the lead ore obtained from the mines in the vicinity of Galena and Dubuque is derived from this limestone, and oceurs in crevices, caverns and hori- zontal seams, irregularly distributed through the rock. In the
42020'
71°03'
50
Ottawa. .....
60.0
71.1
51.7
21.0
50.
41 30
90 40
529
820
65 4
38 37
00 16
450
54.2
174
middle and upper portions of the limestone, according to the observations of Prof. J. D. Whitney, the ore occurs in vertical crevices, mainly, while tho flat sheet, or seam deposits, are con- fined to the lower part of this limestone, and sometimes ex- tend into the blue beds holow. The crevices in which the lead ore is found have, no doubt, been formed originally by the shrinkage of the strata from erystalization, or by some disturb- ing forces from beneath, and have been gradnally enlarged by the decomposition of the exposed surfaces in tho original fissure.
Tho most characteristie fossils of this roek are Lingula quadrata, and a largo fossil resembling a sunflower, somo of which are ten to twelve inehes in diameter, ealled Receptacu- lites. They belong to the Foraminifera, an order of marine organie beings, still lower than the true corals. Iu addition to these, about forty species of marine shells, corals and crus- taecans have been found in tho Galena limestone, and for the most part are of tbo same species with those in the blue lime -. stone below. Among the most remarkable fossil shells of this formation, and of which the Galena limestone has furnished several fine specimens, is a huge Orthoceras, that must have been from fifteen to twenty fect in length when living, and from three to four feet in ciroumference at the largest ex- tremity. They belong to the class Cephalopoda, of which the living Nautilus may be taken as the type, but, instead of he- ing eoiled up like the Nautilus, they were long, straight cham- bered shells, gradually tapering in size from one extremity to the other. This limestone outerops over a considerable por- tion of the region lying hetwcen Rock River and the Missis- sippi, but the productive lead mines are restricted, mainly, to the counties of Jo Daviess aud Stephensou.
In Calhoun County, the upper division of the Trenton group is well exposed in the bluffs of the Mississippi, first appearing about three miles. below Gilead Post Ofice, and extending thenee, with the lower divisions, down to Cap au Gres. It is here a coarse-grained, yellowish gray limestoue, very unevenly textured, and weathers to a cellular or honeycomb-like struc- ture on the exposed surface. It contains no lead ore in this region, so far as is known, or, at least, not enough to be of auy economical value. Small fragments are often found in tbe ravines along its outerop, but they have, most probably, been transported hy drift agencies from somo northern locality. All the divisions of the 'Trenton group afford good building ma- terial, and at some points the roek is very fine-grained and evenly textured; being susceptible of a fine polish, it makes a fine and durable marble. Just below Thebes, in Alexander County, there is an exposure of ahout seventy feet of the up- per part of this group, above the river level, consisting, for the most part, of white and light bluish gray limestones, in layers from two to three feet in thickness. It is generally free from silicious or ferruginous matter, can be eut into auy desired form, and is susceptible of a bigb polish, and is well adapted to various uses as an ornamental stone or marble. The same beds have been extensively quarried for many years in tho vicinity of Cape Girardeau, in Missouri, and tho rock is widely known in the Southwest as the " Cape Girardeau Marble." The entire thickness of this group of roeks is probably not less than seven or eight hundred feet, if we estimate the maximum thickness of the different members, but it probably nowhere measures at a single locality more than 450 or 500 feet.
CINCINNATI GROUP .- This name was first proposed in the Illinois reports to designato a group of rocks that had previ- ously been known under various names, as Hudson River Group, Lorraine Sbales, Nashville Group, Blue Limestone, eto. It immediately succeeds the Trenton group in the ascending series, and forms tho uppermost member of the Lower Silurian system. It consists usually of argillaceous and sandy shales, whieb pass locally into sandstones or argillaceous limestones. In the northwestern portion of the State this formation consists mainly of argillaceous shales and magnesian limestones. Tbe prevailing colors of the beds are light blue and drab, weather- ing to a light asben gray. At Scales Mound, a few miles northeast of Galena, the grado of the Illinois Central Railroad has eut through the lower forty feet of this group, showing a fine seetion, and exposing the fossiliferous beds near the base. The fossils consist mainly of about a half dozen species of small marine shells, belonging to the genera Nucula, Cliodophorus, Plurotomaria, Bellerophon and Orthis. A small Orthoceras (O. gregaria of HALL) is also found here, but not as ahundant as in the same beds in Iowa, where they are crowded together in somo of tbe strata as thiok as they can lie. In the vicinity
STATE GEOLOGY.
of Savanna, in Carroll County, the argillaceous shales of this group are filled with fossil shells in the most perfeet stato of preservation, and mostly adbering to thin plates of limestone that are intercalated in the shalc. The most common species found here are Ortnis occidentalis, O. Bella rugosa, Stropho- mena plan-umbona, S. unicostata, Leptaena sericea, &e., asso- ciated with very perfect spceimens of a fossil coral known as Monticulipora petropolitana. A fine Trilohite helonging to the genus Asaphus is also found at this locality. At Oswego, in Kendall County, the upper part of this group consists of unevenly bedded, dark bluish gray limestone, with shaly part- ings. This locality has afforded two species of Lituites, and three or four species of Enerinites, which have been found very perfectly preserved in the shaly layers. At Wilmington, in Will County, and near Sterling, in Whiteside County, these beds are also exposed, and are filled with the characteristic fossils of this formation. In the southern portion of tho State, this group is found well exposed in the vicinity of Thehes, in Alexander County, where it consists of about thirty feet of sandstone at the base, which is everlaid by about seventy feet or more of shale, mostly arenaeeous, and this succeeded hy about forty foet of compact, dark blue, argillaecous limestone, with shaley partings. Fragments of Trilobites, belonging to the genus Asaplus, are quite abundant here, and the limestones at Orebard Creek, two miles helow Thebes, have afforded two or more species of Glyptocrinas, a fine species of Conularia, and two species of Tentaculites. The shale beds have afforded only a single species of Lingula. The Thebes sandstono is a durable building stone, and has been extensively used at Cairo, for foundation walls and dimension stone.
Need help finding more records? Try our genealogical records directory which has more than 1 million sources to help you more easily locate the available records.