LIBRARY OF THE UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN cop HUMS HISTORM SIIBVEJ ECONOMICAL GEOLOGY OF LL] HOIS'. REPRINTED FROM THE ORIGINAL REPORTS OF THE GEOLOGICAL SURVEY, WITH ADDITIONS AND EMENDATIONS, BY A. H. WORT HEN. STATE GEOLOGIST. VOLUME 2. PUBLISHED BY AUTHORITY OF THE LEGISLATURE OF ILLINOIS, 1882. H. W. EOKKEE, STATE PRINTER AND BINDER, SPRINGFIELD, ILL : \ TABLE OF CONTENTS. CHAPTER I. GEOLOGY OF PEEEY COUNTY. PagOS. By A.. H. Worthen. . 1-23 CHAPTER II. GEOLOGY OF JEB8EY COUNTY. By A. H. Worthen 24-44 CHAPTER III. GEOLOGY OF GREENE COUNTY. By A. H. Worthen 45-58 CHAPTER IV. GEOLOGY OF SCOTT COUNTY. By A. H. Worthen 59-71 i CHAPTER V. GEOLOGY OF WASHINGTON COUNTY. By Henry Engelmann 72- 162 CHAPTER VI. GEOLOGY OF CLINTON COUNTY. By. Henry Engelmann 103-125 CHAPTER VII. GEOLOGY OF MARION COUNTY. By Henry Engelmann 126-156 IV TABLE OF CONTENTS. CHAPTEE VIII. GEOLOGY OP JEFFEKSON COUNTY. Pages. By Henry Engelmann 157-179 CHAPTER IX. GEOLOGY OF COOK COUNTY. By H. M. Bannister 180-201 CHAPTER X. GEOLOGY OF LA SALLE COUNTY. By H. C. Freeman... .. 202-236 CHAPTER XI. GEOLOGY OF CALHOUN COUNTY. By A. H. Worthen : 237-262 CHAPTER XII. GEOLOGY OF PIKE COUNTY. By A. H. Worthen. . . . . 263-283 CHAPTER XIII. GEOLOGY OF ADAMS COUNTY. By A. H. Worthen... .. 284-305 CHAPTER XIV. GEOLOGY OF BEOWN COUNTY. By A. H. Worthen , 306-319 CHAPTER XV. GEOLOGY OF 8CHUYLEB COUNTY. By A. H. Worthen .. 320-336 CHAPTER XVI. GEOLOGY OF FULTON COUNTY. By A. H. Worthen 337-360 TABLE OF CONTENTS. CHAPTER XVII. GEOLOGY OF DE KALB, KANE AND DU PAGE COUNTIES. Pages. By H. M. Bannister... .. 361-377 CHAPTER XVIII. GEOLOGY OF MC HENEY AND LAKE COUNTIES. By H. M. Bannister ... .. 378-388 CHAPTER XIX. GEOLOGY OF KENDALL COUNTY. By H. M. Bannister ... . . 389-403 CHAPTER XX. GEOLOGY OF MOKGAN COUNTY. By H. M. Bannister ... . . 404-419 CHAPTER XXI. GEOLOGY OF CASS AND MENABD COUNTIES. By H. M. Bannister . . 420-434 CHAPTER XXII. GEOLOGY OF TAZEWELL, MC LEAN, LOGAN AND MASON COUNTIES. By H. M. Bannister ..435-449 CHAPTER XXIII. GEOLOGY OF GKUNDY COUNTY. By Frank H. Bradley .. 450-467 CHAPTER XXIV. GEOLOGY OF WILL COUNTY. B y Frank H. Bradley . . 468-488 CHAPTER XXV. GEOLOGY OF KANKAKEE AND IEOQUOIS COUNTIES. By Frank H. Bradley .. 489-504 VI TABLE OF CONTENTS. CHAPTER XXVI. GEOLOGY OF VEBMILION COUNTY. Pages. By Frank H. Bradley 506-532 C H A P T E R XXVII. GEOLOGY OF CHAMPAIGN, FOBD AND EDGAB COUNTIEP. By Frank H. Bradley 533-542 CHAPTER XXVIII. GEOLOGY OF HENDEBSON COUNTY. By H. A. Green i 543-556 CHAPTER XXIX. GEOLOGY OF WABBEN COUNTY. ByH. A. Green 557-570 CHAPTER XXX. GEOLOGY OF MEBCEB COUNTY. By H. A. Green 571-583 CHAPTER XXXI. GEOLOGY OF KNOX COUNTY. ByH. A. Green , 584-596 CHAPTER XXXII. GE LOGY OF STABK COUNTY. By H. A. Green 597-605 CHAPTER XXXIII.- GEOLOGY OF WOODFOBD COUNTY. By H. A. Green. . . . . 606-615 CHAPTER I. PEEEY COUNTY. Perry county lies immediately north of Jackson, which forms its southern boundary, and is bounded on the west by Randolph, on the north by Washington, and on the east by Franklin and Jefferson counties. It embraces a superficial area of twelve townships, or 432 square miles, about three-fourths of which was originally covered with timber. The principal streams within its limits are Little Muddy, Beaucoup and Columbo creeks, all of them the northwestern affluents of the Big Muddy river. The surface of the country is generally rolling, and on some of the streams becomes considerably broken by low ridges, but not sufficiently abrupt to render the land unfit for cultivation; while some portions are quite level, including some flat prairies and a portion of the timbered land known as "post-oak flats." The Beaucoup traverses the county from north to south, nearly through its center, and the prairies occupy mainly the highlands between this stream and the Little Muddy on the east, and Columbo on the west, except the "Grand Coti prairie," which occupies an elevated ridge in the northwestern part of the county. The prairies here, as is usually th case in other portions of the State, occupy the highest ground, but their relative elevation is quite variable, even in a single county. In this county they are mostly surrounded by timbered flats, which gradually pass into more broken timbered lands as we approach the streams. Their surface is generally flat, or gently rolling, passing locally into the broken grassy upland known as "barrens." The geological formations of this county are restricted to the Coal Measures and the superficial deposits known as drift. The Coal Measure strata that formed the original surface in this region, I '2 ECONOMICAL GEOLOGY OF ILLINOIS. before the drift was deposited upon them, consist mainly of arena- ceous, argillaceous and bituminous shales, fine-grained sandstones, and thin beds of siliceous and argillaceous limestone, and these rocks seem to have furnished a large part of the material of which the drift is composed. Hence the soil and sub-soil of this region is arenaceous, with a smaller admixture of clay, and the material exists .in a high state of comminution, a part of it, at least, being reduced to an almost impalpable powder. This physical condition produces certain characters in the soil, which might be supposed to belong only to a stiff clay. When quite dry it rapidly absorbs water, but after having been moist for some time it becomes almost imperme- able, the minute particles of the mass filling all the pores between the larger grains, and closing them so effectually that water is pre- vented from passing through, and remains upon the surface until it is evaporated. If this soil is mechanically worked when thus satu- rated, it becomes exceedingly tenaceous in consequence of the adhesive power of the minute particles of which it is in part com- posed, and appears to be far more clayey than it really is. Gener- ally it crumbles readily when dry, and then shows its sandy character. It is not retentive of moisture, but in a dry atmosphere it readily gives off the water it has absorbed, and re-absorbs the moisture of the atmosphere more slowly and in less quantity than a clay soil does. Occasionally the sub-stratum is found to be a stiff, rough clay, and at other points, sand. In digging wells on the prairie lands, water is frequently found at a depth of ten feet, and is sel- dom deeper than thirty feet, and is usually obtained in the drift deposits before reaching the stratified rocks. The "post-oak flats" are nearly level stretches of upland, which are very sparsely timbered with post oak (Quercus obtusiloba) of sturdy growth, standing far apart, and interspersed with black-jack (Quercus nigra), and young post oak. They form an open forest, and the nearly white soil is but scantily covered with vegetation. The sub-soil is the fmely-comminuted white sandy loam, already described as forming the soil of the adjacent prairies, and reaches to the depth of several feet. The upper soil is quite shallow, and seems to be distinguished from the sub-soil only by a slight admix- ture of vegetable mould. This soil, like that of the prairies, is so finely comminuted as to render it almost entirely impermeable to water, which stands in the depressions upon the surface until it slowly disappears by evaporation. At such localities we find pin oak, scaly-bark hickory, and sometimes laurel oak, associated with the post oak and black-jack. These "flats" extend around the PERRY COUNTY. P prairies, forming a narrow belt between them and the more broken timbered lands adjacent, and also form the highest portions of the broad flat ridges between the streams where no prairies occur. The principal difference between the prairie soil and that of the "flats" consists in the former being more charged with vegetable humus, and being also somewhat deeper than it is upon the "flats." The "barrens," as that term is understood in this region, consist of low hills and ridges, covered with a dense growth of tall grasses and quite destitute of timber, or with only a few scattering trees. The sub-soil on these "barrens" is similar to that above described, and consists cf the same white sandy loam, but their surface con- figuration affords a complete drainage, and they have therefore sustained a better growth of vegetation, which has formed a few inches of good soil, highly charged with humus. The "barrens" become dry early in the spring, from their better surface drainage, and resist the drouth better than the "flats," because the soil is more porous, and absorbs more moisture from the atmosphere. The absence of timber on them appears to be due to the annual fires that sweep over them, fed by the tall grasses that cover the sur- face, a conclusion that is sustained by the fact that as the country is settled, and the fires are kept out, a vigorous growth of young trees soon covers the surface. The "barrens" merge into the post oak hills, which are similar ridges, covered with a heavy growth of timber, consisting in part of post oak, with black oak, black-jack, hickory, etc. The white oak is confined mainly to the breaks of the streams. The principal creek bottoms within the barren region have a soil very similar to that of the flats, but a little coarser, and containing a greater per cent, of vegetable mould, rendering them as dark colored as the prairie soils. The timber is very tall and heavy, and consists principally of the swamp white oak, pin oak, bur oak, red oak, laurel oak, scaly-bark hickory, ash, black walnut, hazel, etc. The character of the upland country above described does not extend very far to the southward beyond the limits of this county, but it includes a limited % area in the northeastern part of Jackson county, and from thence extends southeastward into Franklin and Williamson counties. Of all these varieties of soil, the "flats" are the most unproduc- tive, and will require the greatest amount of labor and skill to bring them up to the highest standard of a good productive soil. This can be done most effectually and cheaply by deep and frequent plowing, which loosens the soil and assists the surface drainage, and 4 ECONOMICAL GEOLOGY OF ILLINOIS. by manuring and plowing under green crops to give the required amount of vegetable mould, and this treatment would probably insure a steady increase in the productive capacities of the soil, until it equaled or perhaps exceeded that of the adjacent prairies. The drift deposits of this section of the State are comparatively thin, seldom attaining a thickness of more than thirty or forty feet, and our knowledge of their general characters -has been derived from the examinations of wells that have been sunk in various parts of the county for water, and from cuts along the Illinois Central rail- road. Here, as elsewhere over the central and southern portions of the State, they consist of beds of clay, sand and gravel, partially stratified, and varying both in depth and arrangement of materials at almost every point where they are penetrated. A well sunk on the northwest quarter of section 16, township 6 south, range 4 west } gave the following section : Soil and sub-soil 3 feet Reddish clay 14 " Sand and gravel 2 " 6 inches Yellow, tough clay TO " 6 This section will give an idea of the general character of these deposits, although probably no two wells would afford exactly the same section. Below these beds we find at some localities the same "blue mud"* already alluded to in the foregoing chapter, as occur- ring in a similar position in Jackson county, while at others, wells are sunk to the stratified rocks of the Coal Measures without meet- ing with it. Hence we may infer that it was either a local deposit that accumulated only in ponds or sloughs, or else it was in part swept away by surface erosion at the commencement of the drift period. Its average thickness cannot be definitely stated, for when it was found in digging for water, the well was generally abandoned as soon as this deposit was reached, because the partly decomposed vegetable matter which it contains rendered the water unfit for use. It appears to be composed, in good part, of vegetable matter, con- sisting of leaves and partially decayed wood, entbedded in a muddy sediment, and has been penetrated at some places to the depth of five to ten feet. It has been found at the following points in this county: At Crawford's mill, on Pipe-stone creek, on section 33, township 6 south, range 3 west; at Mr. Andrew Brown's, on the western edge of Six-mile prairie ; at Old DuQuoin, on section 26, NOTE. *In the Geological Reports of Ohio, Dr. NEWBEKKY recognizes a similar deposit in that State, to which he has given the very significant name of " Forest Bed," from the abundance of vegetable remains usually found in it. PERRY COUNTY. 5 township 6 south, range 1 west, and at a saw mill on a branch of Swanwick creek, on section 15, township 4 south, range 3 west. It usually lies at the bottom of the drift deposits, but at one point in Jackson county it was underlaid by a bed of sand two or three feet in thickness. This sand, as well as the blue mud above it, prob- ably belongs to a period somewhat older than the true drift deposits, and it is very important that wherever these beds are penetrated in sinking wells, or are otherwise exposed, a careful examination should be made for any organic remains that they may contain, as these would no doubt throw some light upon their true origin, and the conditions under which they have been deposited. Coal Measures. All the stratified rocks that outcrop at the surface in this county belong to that division of the Carboniferous system usually known as Coal Measures ; so called because they contain all the coal seams of any practical value that are found in the rocks of this age. They embrace an aggregate thickness of nearly three hundred feet, and consist mainly of soft sandstones and shales, thin beds of limestone, bituminous slates and coal, and include the horizon of two of the principal coal seams at present known in the Illinois coal fields. These coals are associated with the only limestones of any import- ance that are found in the county, and consequently their outcrop is more readily defined and more easily traced than that of the soft shales and sandstones that form the upper two hundred feet of the section. The principal outcrops of these limestones, and the beds associated with them, are along the southern and eastern borders of the county, and they dip gently to the northeastward, at the rate of about eight to ten feet per mile, so that the beds which outcrop along the streams in the southern part of the county are two hund- red feet or more below the surface in the northern part. This has been fully determined by the various coal shafts sunk along the line of the Illinois Central railroad, in this county, and from these we have been enabled to obtain a very complete section of all the beds which outcrop in this county above the DuQuoin coal. This coal is probably the equivalent of No. 5 of the general section, (see chapter 6, Vol. 1, p. 166,) but this is a point we have not yet been able to deter- mine positively. This coal, No. 5, and that above it, No. 6, have so many features in common, that, where but one is developed, it is frequently difficult to say to which horizon it belongs. But, from the best evidence we have been able to obtain, we are inclined to 6 ECONOMICAL GEOLOGY OF ILLINOIS. the opinion that the DuQuoin coal should be referred to No. 5, and the small seam above, which ranges in thickness in this county from a few inches to three feet, is really the equivalent of No. 6, or the Belleville coal. The following section gives the relative posi- tion and thickness of the beds outcropping in this county. The data for the upper portion of this section was obtained from the shafts of Coloma and Tamaroa: Soft micaceous sandstone 15 feet Sandy shale 20 " Massive, hard, ferruginous sandstone 10 " Blue clay shale 20 " Impure iron ore, with fossil shells 2 " Bituminous shale 3 " Coal No. 8 " 9 inches Fire-clay 3 " Sandstone 15 " Sandy shale, with some kidney-ore in the lower part 102 " Hard calcareous sandstone 3 " Black carbonaceous slate, passing into coal No. 7 1 " Cinches Clay shale 3 " Hard, arenaceous, slaty rock 16 " Clay shale ' 7 " Light-gray, hard, sub-crystalline limestone 7 to 9 " Bituminous shale . 1 to 2 " Coal, sometimes wanting No. 6 ? 1 to 3 " Fire-clay or clay shale 3 to 4 " Limestone, light colored and arenaceous 7 " Gray shale 6 " Limestone 6 " Shales, with fossil plants 15 to 25 " CoalNo.5? 5 to 7 " Clay shale, with nodules of hard limestone 15 " 305 feet 3 inches Below the beds represented in the above section there are still at least two hundred feet of strata belonging to the Coal Measures, and containing three or four coal beds in Jackson county, as well as in Northern and Central Illinois, that range from two to five feet in thickness ; all of which probably underlie the entire area of this county, and crop out in the adjoining counties to the south and southeast, while to the west they thin out to less than a hundred feet in thickness, and contain little or no coal of any practical value. All the coals described in the foregoing chapter, as outcropping in Jackson county, underlie those represented in the foregoing section; but they may not be developed in this county so as to be of economi- cal importance. The coal ("No. 6 ?") in this section outcrops on the western borders of the county, on the eastern edge of Six-mile prairie, with a thickness of three feet, and two miles farther north there is another PERKY COUNTY. 7 outcrop, apparently of the same seam, where the coal is only eighteen inches in thickness. In the vicinity of DuQuoin this upper coal has been found at many points, ranging in thickness from two feet down to a mere streak of coaly matter. At the Black Diamond' mine, north of St. Johns, the coal shaft was sunk through the following beds : Clay (surface material) 24 feet Limestone 9 Soap-stone (clay shale) 1 Bituminous shale 1 Coal 1 Fire-clay 4 Limestone 6 Clay shale 5 Limestone 7 Blue clay shale 15 Hard, dark- colored rock (limestone?) 3 Bituminous shale 2 Coal 5 93 feet The Eagle shaft, between the Black Diamond and St. Johns, commences at a level below the upper seam, and the shaft passed through the following beds : Drift clay 10 feet Soft fire-clay ; 6 " Shales.. 15 " Limestone 6 " Shales , .......10 " Coal 6 " Three-quarters of a mile east of the Black Diamond shaft the little coal seam is exposed on Reese's creek, below a compact, gray lime- stone. The coal is here about twenty inches thick. Farther down on this creek, and nearly east of St. Johns, we find another outcrop of apparently this same coal, where it is considerably thicker, and was worked by drifting at an early day ; but the coal appears to have been rather poor in quality, and the work was soon abandoned. At Mr. Archie Wilson's place, five miles southeast of DuQuoin, the limestone forming the roof of the coal outcrops on a small creek near his dwelling, and has been burned for lime. The coal, which is here two feet thick, has been mined by stripping in the creek bot- tom, and, judging from the small fragments left upon the surface, where it had been deposited, as it was taken out of the mine, it appeared to be of good quality. At Pinckneyville, the limestone overlying the small coal was found twenty feet below the surface, on the public square, and was pene- 8 ECONOMICAL GEOLOGY OF ILLINOIS. trated to the depth of five feet without reaching the bottom. At Owen's coal shaft, adjoining the town, the following beds were passed through : Soil, yellow clay, etc. (Drift) 16 feet Quick-sand 1 " Light gray limestone, underlaid by a faint streak of coal 1 " Argillaceous shale 14 " Compact blue limestone 6 " Bituminous shale " 10 inches Coal P. 6 " Clay shale, with calcareous nodules 5 " 49 feet 10 inches This is probably the DuQuoin coal, and it outcrops and has been worked on a ravine southeast of the town, in section 30, township 5 south, range 2 west. A half mile northeast of town, the coal crops out on the Beaucoup ; and several shafts have been sunk to the coal at this point. The bituminous shale, overlying the coal, is here several feet in thickness, and is overlaid, as above, by the blue limestone, which, a little higher up, forms a shoal across the bed of the creek. There seems to be an undulation in the strata here, which brings the main coal above the creek level, just at the town, while it dips below that level above and below. On Beaucoup creek, below Pinckneyville, but few outcrops are found, but enough to show that the coal extends nearly or quite to the county line of Jackson county; and it is quite possible that the coal noticed in the report on that county, as outcropping near the north line of the county, will prove to be the DuQuoin coal. Near the north line of section 6, township 6 south, range 2 west, the following beds may be seen, outcropping below the drift clays : Calcareous shale 1 foot Blue limestone 2 to 4 feet Bituminous shale " 5 inches Coal 6 " Clay shale 5 " Coal has been found in various localities in this neighborhood, in sinking wells, and the overlying limestones and shales outcrop at various points. At the Creek Pond bridge, on the southwest quarter of section 29, the coal crops out in the bank of the Beau- coup, and is overlaid by three feet of bituminous shale. The coal is reported to be from six to seven feet thick at this locality. From Pinckneyville southward, along Beaucoup creek, the coal varies but little from the level of the creek, and may be mined almost any- where within thirty or forty feet of the general surface level. PERRY COUNTY. U In the region west of the Beaucoup, and extending to the west line of the county, very few outcrops qf rocks of any kind are to be seen, as there are no streams that cut through the superficial clays to the stratified rocks below; but the coal and the overlying lime- stone and shale have been found at many points in sinking wells, and they underlie the surface, generally, except where they have been removed by the erosion of the 1 valleys. Southwest of Pinck- ney ville, on the Little Columbo creek, and at various points in town- ship 6 south, range 3 west, the limestones have been found at a moderate depth below the surface, in sinking wells. On sections 14 and 15, the limestone was found about 15 feet below the surface ; and, in the east part of section 9, it outcrops in the banks of the creek, and continues to outcrop, as we ascend the creek, for half a mile or more. On the lower course of the creek it was not met with. Farther west, on a branch in section 4, and in a ravine on the prairie in the south part of section 3, and the north part of section 10, outcrops of the limestone were seen ; and, on section 4, it forms the bed of the creek, and is overlaid by from six to twelve inches of argillaceous shale, and about six inches of coal, probably representing the three-foot coal in the section already given on a preceding page; and this is overlaid by several feet of argillaceous shale, which appears to be fine enough for the manufacture of fire- brick. Higher up the creek, there are some outcrops of shaly, mica- ceous sandstone, which occupy a horizon above the limestones asso- ciated with the coal seams, and may be regarded as belonging to the Upper Coal Measures. On the main Columbo creek, there are no exposures on its lower course in this county, and it is bordered by wide stretches of low bottom land. The first outcrop of the limestone on this creek is on section 18, township 6 south, range 3 west; and they again appear on section 12. The shaly limestone and calcareous shales at the Slate ford, on the southwest quarter of section 1, and at the ford on the northwest quarter of section 2, also belong to this limestone series, and are overlaid by heavy masses of tumbling limestone, from three to six feet thick, that probably belong to the bed above the little coal. These outcrops afford a sure indication of the pres- ence of the main coal, over this portion of the county, at a very moderate depth below the surface. On the northeast quarter of sec- tion 3, township 6 south, range 4 west, a seam of coal, capped by a little blue shale, has been discovered underneath an outcrop of limestone, which appears here in two beds, each about eight feet thick. The coal is reported to be about three feet thick, and prob- 10 ECONOMICAL GEOLOGY OF ILLINOIS. ably holds the same position as the thin streak of coal at Pinck- neyville, and the little seam near St. Johns. The same coal crops out about on mile northeast of this point, on the southwest quarter of section 34, township 5 south, range 4 west, and is overlaid by the same beds as at the former locality. The coal was reported to be three feet thick here, and was used for burning lime from the overling limestone. On section 28 there is another outcrop of the same coal. It is here only eighteen inches thick, and is overlaid by bituminous shale and limestone, as at the other localities. It is underlaid by fire-clay, or clay shale, twenty inches thick, and by limestone similar in character to that above it. At James McMillan's, on the northeast quarter of section 10, town- ship 6 south, range 4 west, coal was found in his well, two feet in thickness, between two beds of clay shale, the overlying limestone having been removed by denudation. In township 5 south, range 4 west, the limestone above this thin coal is exposed in a ravine, on section 32, and was struck in a well, at the foot of the mound near the south line of section 32, at a depth of from twelve to fifteen feet below the surface. There are two of these mounds in this vicinity, and they rise out of the surrounding prairie to the height of sixty to eighty feet, like islands from the sea. They appear to have been formed by the irregular erosion of the surface, anterior to, or during the Drift period, and are formed mainly of sandstones, shales, etc., that belong to a horizon above the limestones that are associated with the main coal seams in this county. One of them is covered with timber, but the other has several farms upon it, and, from the wells and cisterns that have been dug, the following section of its strata has been compiled : Soil and clay, forming the summit 7 feet. Soft sandstone and shales 42 " Coal 1 "6 inches. Argillaceous shale, passing into sandy shale 9 " 6 Ferruginous sandstones, in thin layers 2 " Sandstone and shale, at least ten feet, perhaps more 10 " Compact light gray limestone, not passed through ? " On Pipe-stone creek, a mile south of Denmark, the limestone and shale of the lower coal are exposed. At Mr. Ayers', near the bridge, on section 16, two wells were dug ; and the main coal was found at a depth of thirty-eight feet. At Mr. S. Holliday's, on the southern border of Grand-Coti prairie, a well was sunk, passing through the following strata : PEEEY COUNTY. 11 Soil and tough red clay 19 feet. Shaly sandstone, passing into argillaceous shales, with concretions of iron ore 32 " Blue shale 3 " Coal 1 " 6 inches. This coal is probably the same as that passed through on the mound, and lies above all the limestones associated with the DuQuoin coal, and is probably No. 7 of the general section. These beds underlie all the northern portion of the county, and, having a slight general dip to the northeastward, are far below the surface at the northern line of the county, and are succeeded by higher beds of sandstone and shale. These barren measures cover all the northern portion of the county, to depths ranging from one hundred to two hundred feet, and must be passed through before any workable coal can be reached. The sandstones and shales outcrop on all the streams in the northern part of the county; and some of the beds are sufficiently hard to withstand surface exposure, and form low cliffs of sandstone on some of the small streams. Eeturning to the southeastern part of the county, we find coal on the bank of Span's creek, close to the county line; but, as it was not opened when we visited the locality, its thickness can not be definitely stated. It is variously reported at from two and a half to four feet. Partial outcrops of sandstone and siliceous limestone were observed in connection with this coal, and apparently overlying it. It is probably the same as that found at Archie Wilson's place, five miles southeast of DuQuoin, and most probably represents the three- foot coal in the general section of the Coal Measures of this county. At Wilson's, the coal is but two feet thick ; and the rocks associated with it give the following section : Light gray or brownish- gray massive limestone 6 feet. Irregularly-bedded bluish-gray limestone 2 Clay shale 1 Coal 2 Clay shale 1 Sandy shale, passing into sandstone .' ? The limestone above this coal appears to be identical with the upper bed in the Pinckneyville section, and the coal the same as that on Span's creek, and the two-foot coal in the Black Diamond shaft. The limestone is hard, compact, somewhat brittle, and hard to burn, but makes a strong, though somewhat dark-colored lime. In the bottom on Six-mile creek, near the county line, in Jackson county, limestone has been struck in a well, thirty feet below the surface, which is probably the limestone immediately above the Du- Quoin coal. The following sections of the shafts at DuQuoin and St. 12 ECONOMICAL GEOLOGY OF ILLINOIS. Johns are given to illustrate the variations that occur in the beds associated with the DuQuoin coal, and the unevenness of the sur- face before the drift was deposited, as is shown by the variable thickness of these deposits on what is now a nearly level surface : SHAFT AT ST. JOHNS. Soil and drift clays 43 feet. Gray and compact limestone 3 " 6 inches. Indurated clay shale 4 " 6 Compact gray limestone 2 " 6 Bituminous shale 5 " 6 " Arenaceous and argillaceous shales 16 " Coal 6 " 4 " Clay shale, with iron pyrites. 4 " 85 feet 4 inches. DUQUOIN CENTRAL MINE. Soil and drift clay 29 feet. Blue clay shale 8 " Compact gray limestone 5 " 8 inches. Dark blue shale 5 " 6 Coal 6 " Clay shale, with iron pyrites 2 " 6 Compact nodular limestone, embedded in clay shale 5 " 62 feet 8 inches. MILL SHAFT DUQUOIN. Soil and drift clays 32 feet 5 inches. Hard gray limestone 7 " 1 " Argillaceous shale 8 " 11 Black limestone " 9 Shales argillaceous : 17 " 7 " Coal 6 " 6 " 73 feet 3 inches. DUQUOIN MINE. Soil and drift clay 40 feet. Argillaceous shale 20 " Coal 6 " 7inches. Clayshale 1 " 3 Nodular gray limestone, embedded in shale 4 " Argillaceous shale 2 " 6 " Limestone " 10 Argillaceous shale 3 " 6 " 78 feet 8 inches. PEERY COUNTY. 13 WALL'S COLLIERY. Soil and drift clay 19 feet. Gravel and water-worn limestone 1 " Gray limestone, with clay partings 6 " Shales '. 5 " Limestone " 6 inches. Shales, with calcareous nodules 4 " Hard light gray limestone 2 " Bituminous shale 2 "6 " Argillaceous shale 16 " Coal ..6 " 62 feet. A boring by Mr. Tijou, at this shaft, gave the following section below the coal seam : Fire clay, with nodules of limestone 15 feet 10 inches. Gray and blue shales 46 " 6 " Bituminous shale 4 " 6 Coal " 9 Fire-clay 5 " 5 Gray shale 8 " 4 Sandy shale and sandstone 31 " 6 Limestone 2 " 7 " Bituminous shale 1 " 3 Coal " 6 Fire-clay 3 " 9 Clay shale 17 " 1 Micaceous sandstone... ..0 " 10 Depth of boring 138 feet 10 inches. At this point the work was suspended in consequence of breaking the drill; but it is the purpose of the enterprising proprietor to prosecute it, until the question is settled whether any of the lower seams are developed here thick enough to work. It is probably from one hundred and fifty to two hundred feet from the DuQuoin coal down to the lower coal at Murphysboro ; and the determination of its existence below the DuQuoin coal in Perry county, under such favorable conditions that it could be worked at this point, is a mat- ter of considerable importance to this county, and would justify such an expenditure of capital as is necessary to fully settle this ques- tion. From the sections already given of the beds associated with the coal at Pinckneyville and DuQuoin, it will be seen that there are three, and sometimes four, different beds of limestone above the main coal, ranging in thickness from two to ten feet, and separated by argillaceous, calcareo-argillaceous, or bituminous shales. The upper limestones are usually of a light-gray or brownish-gray color, 14 ECONOMICAL GEOLOGY OF ILLINOIS. quite hard and tolerably massive, affording layers from one to three feet in thickness. They contain numerous fossil shells at some localities, among which are Spirifer cameratus, S. lineatus, Productus Prattenianus, P. longispinus, P. punctatus, P. Wilberanus, P. costatus (?), Athyris Royissii, A. subtilita, Chonetes mesoloba, C . granulifera, Meekella striato-costata, and joints of Crinoidea. The clay shale, which lies immediately above the main coal, and forms the roof, contains a variety of fossil plants, among which the following species have been obtained at DuQuoin and St. Johns, with others still undetermined: Neuropteris rarinervis, Sphenopteris paupercula, Alethopteris aquilina, Pecopteris villosa, P. unita, P. plumosa, Cordaites borassifolia, Sphenophyllum Schlotheimii, S. emarginatum, Asterophyllites equisetiformis, Calamites ramosus, C. cruciatus, C. ap- proximatus, Sigillaria sculpta, S. Brardii, Lepidodendron radicans, Lepi- dostrobus princeps, Megaphytum McLayi, and Caulopteris insignis. It is worthy of remark here that the fossil shells which characterize the upper limestones of DuQuoin and Pinckneyville," as enumerated above, are precisely the same species that are found in the roof limestones of the Belleville coal in St. Clair, Madison and Eandolph counties ; while no plants have been found in the roof shales of that coal at any of the many localities where we have seen it exposed in the counties above named ; and furthermore, we have never seen any such bed of clay shale over the Belleville coal, along its western outcrop, as that which affords the fossil plants at DuQuoin and St. Johns, and, if the coals are identical, we must regard this clay shale, with its embedded plants, as a local intercalation that has not been seen at any of the typical localities of the Belleville coal. Hence, we are inclined to doubt the identity of these coals, and to consider the DuQuoin coal as identical with the Hewlett coal, or No. 5 of the general section of the Illinois coal beds ; and if so, then the Belleville coal would be represented by the little coal that is intercalated in the upper limestones of the Pinckneyville and Black Diamond sections, and this view is confirmed by the fact that this upper coal is considerably thicker on the western confines of the county than it is along the Central railroad, being from three to four feet thick at some of the exposures near the Eandolph county line; while it is nowhere more than two feet in thickness in the eastern part of Perry county, and is often entirely wanting, or is represented by a mere streak of coaly matter. As we have already said elsewhere, these two coals are developed so near together, and are associated. with beds which have so many features in common, being usually -not more than forty or fifty feet asunder, and inclosed PEERY COUNTY. 15 between limestones closely resembling each other, that it is diffi- cult to determine, if but one seam is exposed, to which horizon it should be referred. In St. Clair county, both seams outcrop in the river bluffs, at the old Pittsburg mines ; but, as the lower one is much thinner there than the upper, or Belleville, seam, no attempt has been made to determine its thickness anywhere beyond its out- crop, or to ascertain its average quality. This will no doubt be done when the upper seam has been generally worked out, and the in- creased demand for fuel shall be such as to justify a thorough exploration of the entire thickness of the Coal Measures in that oounty, for an additional supply. But little remains to be said in relation to the barren measures in the northern portion of the county. The soft micaceous sand- stones and shales are frequently met with in small local outcrops in the ravines and on the streams, and Mr. ENGELMANN mentions a single outcrop of limestone in the northeastern corner of the county, which he refers to the Shoal creek limestone of Clinton county. This exposure is on the northeast quarter of section 13, township 4 south, range 1 west, and, with its associated beds, affords the fol- lowing section: Gray shale, with nodules of iron ore 3 feet Hard, bluish-gray limestone 5 Shale 1 Dark-blue slate 3 Coal, said to be twelve inches 1 Clay shale . 6 6 inches 19 feet, 6 inches This limestone is not reported in the Coloma shaft, sunk just north of the county line in Washington county, or any other beds that can properly be considered as the equivalent of the remainder of this section, unless it may be the band of impure iron ore, black shale and nine-inch coal, found about ninety feet below the surface in that shaft, which can scarcely be the representatives of this horizon. These beds are overlaid in the shaft by about sixty-five feet of sandstone and shale, and would seem to be too low down in the section to represent the Shoal Creek limestone. Local intercal- ations of calcareous beds are not uncommon in the Coal Measures ; and it is quite probable that this limestone is of that character; or it may be that it overlies, entirely, the beds passed through in the Coloma shaft, and had been removed by erosion at that point. The. Shoal Creek limestone occupies a position near the horizon of coal No. 9 of the general section of the Coal Measures of Central and Northern Illinois. 16 ECONOMICAL GEOLOGY OF ILLINOIS. All the coals of this county thick enough to be worked with profit, except at some local points where the thin seams outcrop under the most favorable conditions, are those outcropping in the southern portion of the county, embracing the DuQuoin coal, the small coal above it, and the seams still below these, which outcrop in Jackson county, but have never been looked for in the region where the DuQuoin coal is found, because, as the latter occupies a much higher position in the series, it is more accessible, and can be worked at much less expense than the lower coals ; but they may still be found here, and a shaft to reach them must probably be carried down to the depth of about two hundred feet below the coal at DuQuoin. Economical Geology. Coal. It will be apparent, from what has already been said in regard to the geology of this county, that its principal mineral wealth consists in the vast deposits of bituminous coal which under- lie its entire area, and in the southern portion of the county are found so near the surface that they can be worked as economically as any where else in the State. The DuQuoin coal is one of two heavy beds Nos. 5 and 6 that occur about midway in the section of the lower Coal Measures of this State, and are the thickest coals we have, and the most persistent in their development of any in the series, except, perhaps, No. 2, or the lower coal at Murphysboro. In the central portion of the State, where the upper or "barren" measures are well developed, and where there is no extraordinary accumulation of Drift material above the Coal Measures, it is usu- ally found at a depth of from two to three hundred feet, which depth gradually diminishes as we approach the borders of the coal field. In the southern part of Perry county, it is usually found from forty to eighty feet below the surface, and dips slightly to the northward, so that at the northeastern extremity of the county it is from two hundred to two hundred and fifty feet below the surface level. The limestones which are associated with this coal outcrop in the ravines near DuQuoin, on the Beaucoup, from Pinckneyville, south- ward ; on the Columbo, from the neighborhood of Galum, southward ; and at numerous other points in the southern part of the county already noticed; and, wherever these outcrops of limestone occur, the coal may be found at a depth of from thirty to forty feet, requiring but a small investment of capital to put a mine in sue- PERRY COUNTY. 17 cessful operation. But, at the present .time, little or no demand exists for coal off from the railroad line ; and, until the completion of other roads, or the establishment of manufactories in this por- tion of the State, these vast deposits of mineral fuel can be made of little avail. The DuQuoin coal is of excellent quality, above the average of our western bituminous coals ; and, although at some points it contains considerable sulphuret of iron, this occurs mostly in nodules or len- ticular masses, and can be readily separated from the coal in the process of mining. One reason for the bad reputation which our Illinois and other western coals have in Chicago and other markets, is the want of proper care, in mining, to separate the slate and sulphuret of iron (often called "sulphur") from the coal; and con- sequently the coals go to market with much of these deleterious substances mingled with them, which seriously affect their commer- cial value. This results from the carelessness of those in charge of the work, who allow the miners to send out of the mines the entire contents of the seam, including the sulphur and the slate as well as the coal, which they are prompted to do, because it adds so much to the amount of each day's product. The DuQuoin coal averages fully six feet in thickness in this county, and has a good roof of hard, somewhat bituminous clay shale, which admits of taking out the entire thickness of coal, instead of leaving a portion to sustain the roof, as is usually done where the roof consists of soft material. At some points, as at Pinckneyville, the coal is directly overlaid by a hard, blue limestone, that forms a still better roof than the bituminous shale. The coal is usually divided into distinct layers, averaging from six to twelve inches in thickness ; the upper two feet of the seam being usually considered the best coal, is often separated from the other, and sold for smiths' coal. At St. Johns and DuQuoin, the difference between the top and bottom coal is less marked, and no separation is made. The sulphuret of iron occurs mostly in lumps and sheet, which can be easily separated from the coal ; but there is some, occurring in very thin scales in the transverse partings of the coal, that can not be so readily separated from it ; the quantity, however, is small. Some of the layers are very bright and compact, and have a resinous lustre and highly conchoidal fracture, while others are more dull and earthy, and contain considerable charcoal. An analysis of the DuQuoin coal, by Mr. PRATTEN, gave the fol- lowing result : 2 18 ECONOMICAL GEOLOGY OF ILLINOIS. Specific gravity 1.246 Loss in coking 48.9 Total weight of coke 51.1100 Analysis : Moisture 8.5 Volatile matters 40.4 Carbon in coke 48.1 Ashes (light gray) 3.0-100 Carbon in coal 59 .6 This coal-seam is subject to some irregularities, such as "clay slips" or "horse-backs," sometimes called "faults" by the miners, which consists in a thickening of the roof shales, thus cutting off or pinching the coal-seam to one-half or three-fourths of its usual thickness. These irregularities may have resulted from a partial removal, by water currents, of the vegetable matter which formed the coal, and its replacement by a fine muddy sediment at a sub- sequent period. They are not "faults" in the sense in which that term is generally used in mining, which signifies a dislocation or displacement of the strata, so as to prevent their continuity on the original plane of deposit; for in this ease there is no dislocation, but only a replacing of a part of the coal by the same material that forms the roof. At the DuQuoin Central mine, the coal seems to differ somewhat from that obtained from the other shafts in this vicinity ; and it lies about twenty feet nearer the surface than at the Mill shaft, on the same quarter-section, a half mile further north, while the general dip to the northward would not be sufficient to account for this difference of level. It is quite possible that this coal is really the upper seam, which has thickened here to five and a^ half or six feet, and that the other seam has not been reached at all in this shaft. By referring to the section of the shaft, it will be seen that there is only one bed of limestone above the coal, and that a similar limestone underlies it, with a foot or two of clay shale between; and the twenty feet of clay shale, which comes immediately above the coal at all the other shafts, is replaced in this one by five and a half feet of dark-colored bituminous shale. The upper layers of coal in this mine are remarkably free from all earthy matters, and the lamination is nearly obliterated ; the coal has a resinous appear- ance, and breaks with a smooth conchoidal fracture. The bottom coal, however, is inferior, and contains thin seams of slate and iron pyrites. It is also more distinctly laminated ; and the laminae are separated by layers of carbonaceous clod, or mineral charcoal. The roof of this mine is a very firm and highly bituminous slate or shale, which is crossed by numereous fissures running nearly east and west. This slate forms a very good roof, and permits the PERRY COUNTY. 19 taking out of all the coal from the mine. The coal is mined by blasting with powder at all the mines; and at the DuQuoin Central it is so compact that, after the removal of the bottom coal, a second blast is required to remove the top coal. Whether the difference between the coal at this mine and the others in this vicinity results from a local variation of the same seam, or whether it is really a different seam, is a point that we must leave to be fully solved hereafter; but it has many features in common with the No. 6 or Belleville coal, to which w T e are strongly inclined to refer it. The amount of coal accessible at a very moderate depth in this county is enormous ; and an estimate approximating the truth would probably astonish any one not familiar with the subject. We will base our estimate on the main seam at DuQuoin alone, leaving out of the count altogether the lower coals of Murphysboro and Car- bondale, in Jackson county, which probably underlie this county also, and, calling the superficial area in the county four hundred square miles, we have the following result : Six feet in thickness of strata will yield, according to the 'usual mining estimates, 6,000,000 tons of coal to each square mile of surface ; and for four hundred square miles we have an aggregate of 2,400,000,000 tens of coal, which, at $1.50 per ton, the average price at which it sells at this point, would yield $3,600,000,000, an amount more than sufficient to pay the whole national debt. This estimate is undoubt- edly below rather than above the actual amount of the coal to be obtained from the beds underlying the surface of this county alone ; and its abundance, and the facility with which it may be mined, from its proximity to the surface, and other favorable conditions, which have been fully stated above, will make this a desirable loca- tion for the establishment of the necessary manufacturing establish- ments to work up the vast agricultural products of Southern Illi- nois. There is probably no other county in the southern part of the State, where so great an amount of coal can be obtained with so small an expenditure of capital and labor as here ; and the development of these vast resources of fossil fuel, as the increasing wants of the country shall demand, will greatly add to the indus- trial interests of this portion of the State. No satisfactory tests have yet been made to determine whether any of the coals from DuQuoin were sufficiently pure to smelt iron in their raw state ; but it seems probable that a careful selection of the best coal from this region would lead to the accomplishment of this most desirable result, and this would bring the iron ores of Missouri to the coals of Southern Illinois, to be manufactured into metallic iron. The 20 ECONOMICAL GEOLOGY OF ILLINOIS. completion of the railroad from Carbondale to Murphysboro will give an outlet for this coal to the western bank of the Mississippi river, about a hundred miles below St. Louis, and nearly opposite one of the most accessible points on the river to the great iron region of Missouri. At the present time, the principal market for this coal is along the line of the Illinois Central railroad; and the annual product of the mines now opened in this county, for the year 1867, was about 200,000 tons, obtained from less than thirty acres of surface. These mines pay a royalty to the land-owner of 12^ cents per ton, equal to about $25,000 for the mining privileges on about twenty-four acres of surface ; and at this rate the aggregate value of royalty to be paid to the land-owners for the coal in this county, from the DuQuoin seam alone, would be about $300,000,000. Iron Ores. Carbonate of iron is extensively distributed through the Coal Measures of this county, but generally in too limited an amount to be of much practical value. It occurs interspersed through the clay shales, in flat or kidney-shaped concretions, but seldom in a continuous body. When the streams cut through these shales, considerable quantities of ore may be seen along their courses, washed out from the banks of shale on either side, as on Swanwick creek, a short distance above the Pinckneyville and Nash- ville road. Similar ores are found in the shales penetrated in sink- ing wells on the south side of Grand Coti prairie, and at several other points in the county; and possibly it may hereafter be found at some locality in workable quantity. Galena and Native Copper have been found in the superficial clays and gravel beds of this county ; but these minerals do not belong to this region, and have been transported from the north, at the same time and by the same agencies which brought the granite and trap boulders with which they are here associated. Building Stone. Perry county is not well supplied with good building stone ; nevertheless, the limestones of the southern portion, and the sandstones of the upper Coal Measures, which outcrop in the northern part of the county, afford material suitable for founda- tion walls, and some of the limestones may be safely used for bridges and culverts. The light gray limestone forming the roof of the little coal seam in the vicinity of DuQuoin and Pinckneyville, appears to be a durable building stone, and has been used in con- structing culverts along the railroad north of DuQuoin. At some points this rock makes a very good quick-lime, as at Mr. Archie Wilson's, five miles 'southwest of DuQuoin. The arenaceous lime- PERRY COUNTY. 21 stone, which outcrops in the northeast part of the county, seems to be suitable for rough walls, and will supply the local demand in the vicinity of its outcrop. The sandstones are usually rather thin- bedded where we have seen them exposed in this county, and are too soft to be safely used in the construction of costly buildings ; but they are easily dressed, and answer for light walls, flagging, etc. The sandstones outcrop most abundantly on the Little Muddy, in the northeastern part of the county. Sand and Clay, for bricks, may be found at almost any place where it may be desirable to manufacture them ; and, from the abundance of coal, and the economy with which they can be burned, brick will always be one of the cheapest and most easily obtained materials for building purposes in this county. Agricultural Resources. In discussing the topographical features of this county, we have already spoken of the prairie lands, the post- oak flats, and the barrens, and discussed the difference in the character of the soils to which these peculiar features of the sur- face may be attributed; and but little remains now to be said on this subject. The bottom lands in this county are restricted to some narrow belts along some of the principal streams. On the Beaucoup they sometimes reach a mile or more in width, though usually they are narrower. The prevailing timber on this stream is the white oak, swamp white oak, bur oak, laurel oak, chestnut oak, red oak, syca- more, black walnut, sweet gum, scaly-bark hickory, etc. In the breaks and bluffs of the creek, the white oak, a tree otherwise not common in this country, is quite abundant, especially south of Pinckneyville ; and these white oak lands are reckoned among the most fertile lands in the county. The soil on these bottom lands resembles somewhat that of the post oak flats. The sub-soil is a nearly white sand, with a small admixture of clay, and some fer- ruginous nodules; and the soil is composed of the same materials, with the addition of more vegetable matter, or humus. Although this post oak soil at first seems rather poor, it would probably im- prove rapidly under a judicious system of cultivation, its seeming deficiencies being due to its physical constitution rather than to a lack of any of the elements to form a good soil. The bottoms on Columbo and Swanwick creeks are similar to those of the Beaucoup, and are covered with a similar growth of timber. On Reese's creek the bottoms are quite narrow in the south part of township 5, where the limestones outcrop, and are scarcely wider above; but in the vicinity of DuQuoin they widen to about three- 22 ECONOMICAL GEOLOGY OF ILLINOIS. quarters of a mile. The principal growth of timber is the swamp white oak, scaly-bark hickory, black walnut, ash, over-cup oak, with an abundant growth of hazel as underbrush, which indicates a soil of good quality, and sufficiently dry for cultivation. Some miles lower down, the creek enters the bottoms of the Little Muddy, which are here two miles or more in width, and are heavily tim- bered with a growth similar to that on Reese's creok. At the crossing of the road, east of Old DuQuoin, the bottoms of Little Muddy are about a mile wide, and are covered with a splendid growth of swamp white oak, over-cup oak, scaly-bark hickory, red oak, ash, and some water oak, with but little hazel or other underbrush. At Kirkpat- rick's bridge, on section 18, the bottom is about a mile wide, and averages this width as far north as the north line of township 6, and from this point gradually grows narrower to the north line of the county. A portion of these bottom lands is now too low and wet for cultivation ; but they are valuable for timber, and will event- ually become dry enough for farming purposes. The character of the soils on the different varieties of upland in this county has already been briefly discussed ; and but little remains to be said on this point. The soils and sub-soils consist mainly of an exceedingly fine sandy material, mixed with a smaller portion of clay ; and its stiff, clayey appearance is more properly due to the fineness of the material than to the proportion of clay it contains. This peculiar character renders it close and compact, and hard to drain, and not easily worked, except when quite dry. Deep plowing or sub-soiling, and a liberal use of manures from the farm-yard, will rapidly improve the quality and texture of this soil, rendering it more porous, so that the water falling upon the surface will not be retained there, but allowed to pass freely through the soil into the earth below. When manures are not obtainable at a small cost, the same end may be attained by plowing under the green crops. The post oak flats were entirely neglected by the early settlers, and the land regarded as unfit for cultivation ; but they are now gradu- ally being improved, and if judiciously treated, will eventually become productive. The growth of post oak timber by no means indicates a poor soil; and the arboreal vegetation of these flats is probably due to the mechanical condition rather than the chemical composition of the soil. The prairies generally have a good soil, and produce annually large crops of cereals of various kinds ; and yet the main difference between the soil of the prairie and that of the adjoining flats consists PERRY COUNTY. 23 in the larger amount of humus or vegetable matter which the for- mer contains, derived from the long-continued growth and yearly decay of the grasses which everywhere cover the surface of the prairies. These annual crops of grass have added to the soil a large per cent, of organic matter, though far less than they would have done if, instead of being permitted to decay upon the surface, they had been turned under by the plow. The blue mud, which has already been alluded to in treating on the drift deposits of this county, may prove to be a valuable ma- nure, especially for the post oak flats. It appears to be composed mainly of leaves and partially decayed wood, with an admixture of clay, such as we often find accumulating in swamps or sloughs, and must contain, in a concentrated form, the organic elements, the humus, alkaline and other salts, which are the most valuable con- stituents of manures. It occurs at many localities in the county in great abundance, the deposit sometimes attaining a thickness of from five to ten feet ; and, indeed, at one locality - on the west side of Six-mile prairie, at Mr. Andrew Brown's, it was said to have been penetrated to the depth of sixteen feet without reaching the bottom. If this substance should prove to be as valuable as its appearance would indicate, it will add greatly to the productive capacities of the soils of this county, and, instead of being regarded as a nuisance, as it has hitherto been, will be eagerly sought after by the farmer, and liberally applied to his partially worn-out lands. An experiment could easily i>e made by any farmer living near a known outcrop of this material, and the application of a few loads to the poorest soil on the farm would in a year or two determine its value as a manure. Although it is generally found at a consider- able depth below the surface level, it will most probably be found outcropping on some of the streams, and may thus be obtained with but little labor. Where it has been found in digging wells, it occurs from fifteen to twenty-five feet below the surface. CHAPTER II. JEESEY COUNTY. This county lies upon the western borders of the State, at the junction of the Illinois river and the Mississippi, and includes an area of about ten townships, or three hundred and sixty square miles. It is bounded on the north by Greene county, on the east by. Macoupin and Madison counties, and on the south and west by Madison county and the two rivers above named. The central and eastern portions are mostly prairie, and are comparatively level or gently rolling; while the western portion becomes more broken as we approach the river bluffs, which are intersected by deep ravines, separated by narrow ridges, many of which are from one hundred and fifty to two hundred feet in height* This portion of the county is heavily timbered. The county is well watered by Macoupin creek and its tributaries, on its northern boundary, and by Otter creek and the Piasa and their affluents, which intersect the southern and western portions of the county. The geological structure of the county presents an interesting and varied field for investigation; and the outcrops of the stratified rocks include a thickness of about one thousand feet of strata, ranging from the lower Coal Measures to the Trenton limestone of the lower Silurian period, inclusive. In addition to the stratified rocks, and overlying them, we find the usual Quaternary deposits, reaching an aggregate of a hundred feet or more in thickness, and consisting of alluvium, loess and drift, tfhese deposits attain their greatest development in the vicinity of the river bluffs, and thin out to an average of not more than thirty or forty feet, after the gene- ral level of the high land is attained, where the loess disappears, and only the lower division of the series, the drift, remains. JEESEY COUNTY. 25 The elevation of the Devonian and Silurian rocks to the surface in this county is due to the influence of the Cap au Ores axis, which crosses the Illinois river about five miles above its mouth, producing a dislocation of the strata, and forming, a double tier of bluffs, which are separated by a narrow valley from the point where this axis first makes its appearance on the eastern side of the Illinois river, down nearly to Mason's Landing, the beds on the opposite side of this valley dipping in opposite directions, while those on the west side of this axis have been thrown down, so as to produce a decided fault in the stratification. The following section will show the order of super-position and comparative thickness of the different groups of rocks occurring in this county : ll P. 3 100 feet. 200 feet. 6 feet. 70 to 70 feet. 150 feet. 200 feet. 80 to 100 feet. 10 to 15 feet. 120 feet. 40.to 50 feet. 40 feet. Quaternary. Lower Coal Measures. Chester Limestone? St. Louis Limestone. Keokuk Limestone. Burlington Limestone. Kinderhook Group. Hamilton Limestone. Niagara Limestone. Cincinnati Group. Trenton Limestone. 26 ECONOMICAL GEOLOGY OF ILLINOIS. We shall briefly describe the strata represented in the foregoing section, taking them up in their order of sequence, beginning at the top of the series: In the Quaternary system, we include the alluvium, loess and drift, comprising all the loose, superficial material that overlies the stratified rocks. The principal alluvial deposits of this county are the bottom lands bordering on the Illinois river, which form a belt on the eastern bank of that stream, with an average width of about one and a half to two miles. The soil on this bottom land is a deep sandy loam, formed mainly by the wash from the high lands of the adjacent bluffs, and the sediment deposited by the river, which submerges the lower portion of it during its annual over- flows. It is exceedingly fertile, producing annually large crops of corn, wheat, oats, barley and potatoes, which are often grown year after year on the same ground, without manure, and with no per- ceptible diminution in the value of the crops. The surface of these lands is gradually being elevated from year to year by the causes already alluded to; the swampy portions are filling up, and the arable area is thus constantly increasing. When the country was first settled, these bottoms produced annual crops of most luxuriant grasses, growing oftentimes, in wet portions, to a height of six or eight feet, and the annual decay of so great an amount of vegetable matter upon the surface produced a mala- rious atmosphere that was quite deleterious to the health of the early settlers upon these lands. But, when the soil was once broken and the ground brought under cultivation over a considerable portion of the surface, and the luxuriant growth of vegetation on other portions was consumed by the herds of cattle that were allowed to graze upon it, the general health of the settlers improved from year to year, until at the present time these bottom lands are considered to be quite as healthy as those upon the prairies, and more so than the timbered lands of the adjacent bluffs. The river bluffs, both on the Illinois and Mississippi, are covered with a heavy deposit of Loess, varying from twenty to sixty feet in thickness. It presents its usual characteristic features in this county, and is composed of buff-colored marly sands and clays, sometimes partially stratified, and usually filled with shells of the common fresh-water and land varieties. It does not appear to extend very far back from the river, and its deposition is restricted to the slope between the general level of the prairie region and the bluffs bor- dering the river bottoms, while it appears to thin out rapidly as we recede from the river bluffs towards the higher portions of the adja- JEKSEY COUNTY. 27 cent country. It is also found filling some of the valleys of the smaller streams for several miles back from the river bluffs, showing that these valleys were excavated by other agencies than tjbe streams which now run in them, and at a period anterior to the existence of our present water-courses. At Thos. K. Phipps' place, on the highlands between Otter and Coon creeks, heavy beds of loess and modified drift are found filling the lateral valleys leading to these streams, and also covering the slopes of the hills so that the under- lying rocks are but rarely seen. These deposits are from sixty to a hundred feet in thickness ; and the modified drift contains bands of sandstone and conglomerate. These sands are somewhat mica- ceous, and the particles of mica have excited expectations that these beds would afford valuable deposits of the precious metals. For a more minute description of the loess formation, the reader is referred to a previous chapter on the general geology of the State. The drift deposits of this county do not present any peculiar fea- tures, so far as we are able to discover. One of the most satisfactory natural sections observed in the county was found on Otter creek, on the lands of Mr. McAdams, where the beds had been cut through by the waters of the creek. The exposure at this locality exhibited about twenty feet of yellowish-brown clay at the top, below which was seen from twenty to thirty feet of sand and gravel, with boulders; and this was underlaid by about fifteen feet of blue plastic clay, extending below the bed of the creek. Boulders of granite, sienite, green-stone, quartz-rock and porphyry, are , often met with in the beds of the small streams, and have been washed out of the gravel bed, which forms the middle division of the drift in this vicinity. This gravel bed furnishes the main supply of water for the wells in this county, and the upper clay bed affords an inexhaustible supply of clay suitable for the manufacture of brick. About two miles south- east of Fieldon, on a small branch of Otter creek, a pottery has been established, and is supplied with clays from the drift, by using a mixture of blue plastic clay with the brown clay above. It makes a rather coarse and inferior quality of ware, by no means equal to that made from the argillaceous shales of the lower Coal Measures. But it seems quite probable that, by thoroughly washing the blue clay before mixing, it may be made to answer a valuable purpose for the manufacture of the coarser varieties of ware, such as drain-tile and the earthen cylinders used in sewers ; and, as the supply of these clays, from the thickness of the beds, may be considered as unlimited, the question of its adaptability to such purposes should 28 ECONOMICAL GEOLOGY OF ILLINOIS. be thoroughly tested. Fragments of wood, and even trees of con- siderable size, are often met with in sinking wells or in making other excavations in the plastic clay. Coal Measures. The rocks in this county that may properly be referred to the Coal Measures include a thickness of about one hundred and fifty to two hundred feet, embracing three or more seams of workable thick- ness. These coal beds underlie the eastern portion of the county, and outcrop on the Piasa at all points north and east of the Jersey- ville and Alton road, as well as on the southern affluents of the Macoupin. On the extreme western confines of the coal region the measures are thin, and are sometimes composed entirely of sand- stones and shales, with no coal of any value; but as we proceed eastwardly, toward the center of the coal field, the measures increase in thickness, and the seams of coal become more numerous. The following section, compiled from the various local sections we were able to see, may be taken as the approximate thickness of the measures in this county: Gray shale, partially exposed west of Brighton 10 feet Compact, brownish-gray Fusullna limestone 6 Brown calcareous shale... 3 Green and blue argillaceous shale 8 to 10 " Coal No. 6 2& to 3 Shatyclay Vfy. " Calcareous shale, with bands of limestone and septaria 6 Clay shale 8 to 10 Limestone and bituminous shale 3 " Coal ("Hewlett seam") No. 5 3 to 4 " Shaly fire-clay 1 to 2 Nodular argillaceous limestone , 4 " Gray shales 30 Bituminous shale, sometimes overlaid with limestone, probably representing the horizon of coal No. 2 3 to 4 " Sandstone and shale 40 to 50 CoalNo.l? 2to 3 Clay shale 2 " Nodular, dark-blue, compact limestone, in local outcrops 3 to 5 Shales and sandstone ; 10 to 20 The upper beds in this section, including the two upper coal seams. were only seen exposed together at one locality in the vicinity of Brighton, in the southeast corner of the county, on the head-waters of the Piasa, and about one mile west of the town. The upper limestone in the section above is a gray, compact stone, weathering to a rusty brown color, and sometimes occurs in massive strata, from two feet to two and a-half in thickness, with its surface thickly JEKSEY COUNTY. 29 covered with Fusulina. It also contains plates and spines of Echino- chidaris, Athyris subtilita and Spirifer liqeatus. From the calcareous shale below the limestone, we obtained very large joints of crinoidea, Productus semireticulatus, P. longispinus, Spirifer lineatus, S. Kentuck- ensis, Retzia Mormoni, Chonetes mesoloba, C. granulifera, an undeter- mined Platyceras, etc. The upper seam at this locality, which we refer without hesita- tion to the horizon of coal No. 6, of the general section, has been opened here by drifting into the hillside along the line of outcrop, and has also been passed through in the shafts which have been sunk in this vicinity down to the lower No. 5 coal. It is somewhat thinner here than the lower seam, and has a roof of clay shale that requires thorough cribbing to enable the miners to work the coal with safety; and for these reasons they prefer to work the lower seam, which has a better roof, and is also somewhat thicker than the one above it. These coals are separated here by from twenty to thirty feet of shaly strata, and are both underlaid by a calcareous clay shale, passing into hard argillaceous limestones, which are gen- erally concretionary, and sometimes appear as nodules of limestone embedded in the shale. The lower seam is overlaid by -'a brown argillaceous limestone, which sometimes comes immediately above the coal, or is separated from it by a thin bed of bituminous shale. At the openings near Brighton, the seam ranges from three feet to three feet nine inches in thickness, and affords a coal of fair quality, but containing more sulphuret of iron than the coal from the upper seam, which is here considered the best smith's coal. At Samuel Austin's place, on the southeast quarter of section 10, township 7, range 10, this seam has also been opened, and the coaj from this mine is said to be the best yet found in the county. It ranges from three and a-half to four feet in thickness, with a good slate and limestone roof, and is said to afford a good coking coal. At Andrew Williamson's place, on section 16, in the same town- ship, the coal has about the same average thickness; and the ex- posure here afforded the following section from the creek to the coal : Limestone, compact and brownish-gray 4 feet Coal No. 5 3& to 4 Shaly flre-clay 4 to 6 Gray nodular limestone 4 Shale, partially exposed 25 Bituminous shale (coal No. 2 ?) 2 to 4 Shale, partly exposed down to the creek level ...22 30 ECONOMICAL GEOLOGY OF ILLINOIS. This seam has also been opened on the southwest quarter of sec- tion 10, township 7, range 10, where it is about five feet thick, and was worked by Mr. Langley, in 1854, at the time of our first visit to this county. The coal afforded by this seam varies considerably at the different mines where it has been worked. At some localities it contains considerable sulphuret of iron, and cannot be used for blacksmithing ; at others it is quite free from it, and becomes a good smiths' coal. It everywhere contains carbonate of lime, in thin white plates, traversing the cleavage joints of the coal ; and at some localities the sulphate of lime, or selenite, in thin crystaliza- tions, is found in it, but these calcareous minerals do not affect the quality of the coal injuriously, like the combinations of sulphur and iron. This seam, from the localities above cited, affords nearly all the coal at present mined in this county. It will probably be found to underlie the greater part of townships 7 and 8, range 10. The strata appear to lie very nearly horizontal, though at the Langley mine the coal dipped to the northeast sufficiently to drain the mine through the a.dit which enters the hill in a southwesterly direction. This is probably the general direction of the dip in this vicinity. The lower seam, which is exposed on the Piasa, east of Delhi, has been opened at various localities along the bluffs of the creek, within a distance of two miles from the town. The coal varies in thickness from two to three feet, and is overlaid by a few inches of bituminous shale, which passes upward into a brown or chocolate-colored clay shale. It is underlaid by fire clay, the thickness of which was not determined, and about ten feet of sandy shale and sandstone, which rests directly upon the St. Louis limestone. About half a mile west of Langley 's mine a dark bluish-gray concretionary limestone is seen in the bed of the creek, from three to four feet in thickness, which is overlaid by ten or twelve feet of gray shale. This limestone closely resembles that usually underlying the Exeter coal seam in Greene and Scott counties; but if it is the same, the coal is wanting here. We also saw a similar limestone a half mile north of Delhi, in a small ravine on the west side of the Jerseyville road; but no coal seam appeared to be associated with it here. If this is the lime- stone usually associated with the No. 1, or Exeter, coal, then the seam which has been opened on the Piasa, near Delhi, and under- lies this limestone, would be the Conglomerate coal, and the equiva- lent of a thin coal found below Moore's coal, on the Little Sandy, in Scott county, in a similar position, for a description of which, see the report on that county, in a following chapter. The coal JEKSEY COUNTY. 81 which this seam affords is much inferior in quality to that obtained from the higher seams, and consequently it is not much worked at the present time. Coals Nos. 2, 3 and 4 of the general section do not appear to be well developed in this county. The" western boundery of the coal field, in that part of the county lying north of Jerseyville, is not well denned, in consequence of the scarcity of any rock exposures below the drift. In sinking a well at the steam mill in Jerseyville, a few feet of soft micaceous sandstone were passed through, which no doubt belong to the Coal Measures. From Jerseyville the general trend of the western borders of the Coal Measures is to the northeast ; and, on Phill's creek, at J. Fink's place, on section 29, township 9, range 10, a thin-bedded micaceous sandstone is exposed, about six feet in thickness, and extending below the creek level. Some of the layers are finely ripple-marked; and the rock, when of the proper thickness, makes a good flagging-stone. The streams in the northeast part of the county run through broad valleys, filled with drift to such a depth that the stratified rocks are rarely exposed ; and, consequently, it is impossible, without artificial excavations, to determine the precise line of boundary between the different formations. The sandstone on Phill's creek is no doubt a Coal Measure deposit, and probably the same as that penetrated at the mill in Jerseyville. It probably represents the sandstones lying near the base of the Coal Measures. Two miles nearly due north of Jerseyville, in the bed of a creek, a chert bed is exposed on the south- west quarter of section 4, which no doubt belongs to the limestones below the Coal Measures. Passing below the Coal Measures, we come directly upon the lower Carboniferous limestone series, the different members of which form a broad limestone belt that extends from the western borders of the Coal Measures -to the river bluffs. The limestone formation is mainly represented by the four divisions mentioned in the general section; but, at two or three points in the county, we saw some beds of arenaceous material, lying between the Coal Measures and St. Louis limestone, that appeared like thin outliers of the Chester group. On the southwest slope of Beatty's Mound, in a little run which empties into Otter creek, we found a stratum of white sandstone or siliceous limestone, about one foot in thickness, containing Retzia vera, Athy- ris ambigua, and an undetermined shell like a Modiola; and below this stratum a few feet of thin-bedded sandstone was seen, which rest upon the St. Louis limestone. At Cooper's quarries, about three miles southwest of Jerseyville, the St. Louis limestone is overlaid by similar beds, consisting of about four feet of brown ferruginous 32 ECONOMICAL GEOLOGY OF ILLINOIS. sandstone, and about two feet of light gray calcareous sandstone, very much like that at Beatty's Mound, except that it contained no fossils, so far as we observed, at this locality, and was associated with some thin beds of chert. Nodules of a fine iron ore were found here in the shaly portions of the brown sandstone, underlying the light gray rock. The lithological character of these beds, and their stratigraphical position, would tend to confirm the conclusion that they are the attenuated representatives of the beds above named, even in the entire absence of characteristic fossils. In Kandolph county, this group has an aggregate thickness of more than six hun- dred feet; but it thins out rapidly toward the north, and, in the bluffs at Alton, we recognize it with an aggregate thickness of only about fifteen feet. In Jersey county, the beds representing this group are only from six to seven feet thick ; and north of this county, they have not yet been recognized at all ; and, if they were deposited at points further north, the strata have been worn away by the denuding forces which seem to have been in active operation at the commencement of, or anterior to, the coal-bearing period. St. Louis Limestone. This formation appears to be considerably thinner in this county than in Madison, and also changes somewhat in its lithological characters, on the north side of the Piasa. No single section was seen in this county that exhibited a greater thick- ness than about seventy-five feet of this limestone ; and its maximum thickness in the county probably does not exceed one hundred and twenty feet. About one mile above the Piasa, the upper portion of the river bluff consists of about seventy-five feet of strata that may be referred to this formation, consisting of buff and brown magnesian limestones. The upper half of the bed is here a thin-bedded, buff- colored limestone, that becomes shaly on exposure to the atmosphere ; while the beds below are tolerably massive, affording layers from one to two feet in thickness. These lower beds contain Spirifer lateralis, S. Keokuk, Orthis dubia and a Syringopor* of undetermined species. Below these massive beds we find about six feet of earthy, ash- colored, hydraulic limestone, the same, probably, that is quarried at the cement mill on the Piasa. Under the hydraulic limestone there is a covered slope of sixty feet in which the strata are not exposed ; and below this slope there is an exposure of one hundred and twenty feet of Keokuk limestone, extending to the river level. The beds forming the upper portion of the bluff at this point present the same general characters observed a short distance west of Delhi, where this limestone is immediately overlaid by the Coal Measures ; and the heavy beds of evenly-stratified and concretionary gray lime- JERSEY COUNTY. 33 stone, which form the upper division of this formation at Alton and St. Louis, are scarcely represented at all in this county. At the hydraulic mill owned by the heirs of the late Robt. G. Smith, Esq., on the north side of the Piasa, the hydraulic limestone is eight feet in thickness, and is underlaid by about thirty feet of shaly magnesian limestone, extending down to the level of the creek. Overlying the hydraulic limestone at this locality, are beds of brown magnesian limestone, similar in character to that just described as overlying the hydraulic limestone in the section at the river bluff, and containing the same fossils, with some additional species, such as Rhynchonella subcuneata and Pal&acis cuneatum. On the Piasa, two miles southwest of Delhi, a series of brown and gray limestones are exposed in alternating beds, which attain a thick- ness altogether of about forty feet. Some of the brown beds are quite soft, and weather to a brown calcareous shale. The gray beds are compact and massive, and afford a good building stone. The abutments for the railroad bridge on the Piasa are built from the gray beds which outcrop in this vicinity. The strata at this locality afford the same Jfossils already named as characteristic of these limestones at other localities in this county ; and I also saw, in the cabinet of Dr. FARLEY, of Jerseyville, a specimen of Melonites mul- tipora, which he informed me was obtained at the quarries two miles west of Delhi, associated with Rhynchonella per-rostellata, and the species above named. Cooper's quarries, on a branch of Otter creek, about three miles southwest of Jerseyville, are in this formation ; and the rock at this locality presents the same general characters as at the other locali- ties already mentioned. This group thins out toward the north; and, although no satis- factory exposure of the bed was seen northwest of Jerseyville, we will hazard the opinion that it nowhere exceeds a thickness of forty or fifty feet in the northern part of this county. About five miles above Mason's landing the St. Louis limestone is found, forming a part of the river bluff, where it has been thrown down by the dislocation of the strata at the point where the Cap au Ores axis crosses the river. The beds exposed here present the same lithological characters as at Alton, and the rock is quarried and burned for lime. The beds here dip nearly south, at an angle of about twenty-five degrees. There are from forty to fifty feet in thickness of these gray limestones exposed here ; but the strong dip soon carries them below the surface, and the extent of the outcrop is quite limited. 3 34 ECONOMICAL GEOLOGY OF ILLINOIS. Keokuk Limestone. This formation, which underlies the St. Louis limestone, has a maximum thickness in this county of about one hundred and fifty feet. In the bluffs of the Mississippi, between Jersey Landing and the Piasa, it is well exposed, and forms the upper part of the bluff, a half mile below the first named point; but a gentle dip down the river, or in an easterly direction, soon brings it down to the river level; and, about a mile and a half above the mouth of the Piasa, it forms only the lower portion of the bluff, while the upper part is formed by the St. Louis limestone, as described in a foregoing section. The upper part of the formation is hidden at this locality by a covered slope about sixty feet in thickness; but, on the branches of Otter creek, it is found to con- sist of blue and buff-colored calcareo-argillaceous shales, such as usually characterize that portion of the formation known as the geode bed; and it is here, as elsewhere, filled with siliceous geodes, containing crystals of calcite, quartz and the common botryoidal forms of chalcedony. The lower part of this group, comprising about two-thirds of its aggregate thickness, may be described as a thin-bedded, cherty, bluish- gray crinoidal limestone, with partings of blue or yellow marly clay between the beds. It is well exposed on the forks of Otter creek, between Grafton and Jerseyville ; and sections of the strata from twenty to forty feet thick may be frequently seen along the bluffs of these streams. It is generally thin-bedded, seldom affording strata more than a foot in thickness ; and these are usually separated by thin seams of marly clay. On the surface of the limestone layers, where the clay has been removed by weathering, the characteristic fossils of this formation may be obtained in a fine state of preser- vation. Very fine specimens of Archimedes Owenana have been found here; also Oligoporus Dana, Agaricocrinus Americanus, A. Wortheni, A. Whitfieldi, Actinocrinus Nashvilltz, A. Mississippiensis, Productus punctatux, P. semireticulatus, Athyris incrassata and Zaphrentis Dalii, which are the most common fossils afforded by these limestones on Otter creek. Northwest of Jerseyville, where this limestone undoubt- edly forms the fundamental rock on which the Quaternary deposits rest, no considerable exposures of it were found, for the reason that there are no streams on the south side of the Macoupin, and west of Phill's creek, of sufficient size to cut through the superficial de- posits and expose the rocks below. Burlington Limestone. This important subdivision of the lower Carboniferous limestone series is well developed in this county, JERSEY COUNTY. 35 with an aggregate thickness of about two hundred feet, and under- lies a belt of country several miles in width along the river bluffs, throughout nearly the whole extent of the county from northwest to southeast, until it finally passes below the river level a short distance below Jersey Landing. Immediately below Jersey Landing, the bluff is composed entirely of this limestone, and is one hundred and ninety feet in height above the river. It consists of alternate layers of light-gray and brown limestone, with a considerable amount of cherty material disseminated through it in seams and nodules. About midway of the mass, at this locality, there is a bed of yellow, partly decomposed chert, from fifteen to twenty feet in thickness ; and above this the limestone becomes more thin-bedded and cherty than it is below. The lower part of the formation is a regularly-bedded light-gray limestone, the strata ranging from six inches to two feet in thickness, and appearing to be composed almost entirely of the plates and joints of crinoids, forming what is termed a crinoidal or encrinital limestone. The remains of crinoids in a good state of preservation, however, are extremely rare in this formation at every locality we were enabled to examine in Jersey county; and in this respect it presents a marked contrast to the outcrops of this limestone at more northern localities. The principal fossils which it affords in. Jersey county are Euomphalus lotus, Productus semireticulatus, Spirifer plenus, S. Grimesi, S. striatus, Orthis Michelini, Athyris lamellosa, and Chonetes Illinoisensis. The limestone bluffs in the vicinity of Jersey Landing are exceed- ingly bold and picturesque. They are capped by heavy beds of Loess, which makes the entire elevation from two hundred and twenty-five to two hundred and fifty feet in height, with a precipitous limestone cliff from one hundred and fifty to two hundred feet high. At the time of our last visit to this locality (in May, 1864), a pair of eagles, guided by that instinct which leads these birds to select the most inacces- sible location fpr their breeding places, had built their nest upon a projecting shelf of limestone, about thirty feet below the summit of the perpendicular limestone cliff, about half a mile above the village. Below them was a mural wall of limestone, nearly one hundred and fifty feet high, and from above they could only be reached by a rope let down a feat which but few would be bold enough to under- take. While we were prosecuting our examinations at the foot of the bluff, the male bird sat perched upon a tree at the summit of the cliff, keeping a vigilant watch, while its mate occupied the nest below. 36 ECONOMICAL GEOLOGY OF ILLINOIS. The view from the summit of these bluffs is very fine, and will well repay the labor of climbing to the top. To the south the turbid Missouri, and the rich fertile valley which separates the two great rivers at this point, can be seen for many miles in extent from east to west ; while the broad reaches of the Mississippi, which here runs nearly due east, form a magnificent foreground to the picture. From Otter creek to the Macoupin the bluffs are formed mainly of this limestone, with an occasional outcrop of the Kinderhook group at the base ; and in the vicinity of Fieldon it outcrops on all the smaller streams. At Theodore Lance's lime-kiln, on Borer creek, this limestone forms perpendicular. bluff s from forty to fifty feet in height. The rock here presents its usual characters of a light gray crinoidal limestone, with cherty seams and nodules, and is quarried for lime- burning. A bed of chert four or five feet in thickness forms the top of the exposure at this point. The quarries at this locality afford the same fossils already mentioned as occurring near Jersey Land- ing. Near the mouth of Sugar creek a hundred feet or more in thick- ness of this limestone may be seen at a single exposure. At the farm of Mr. James Reddish, on the southwest quarter of section 4, township 8, range 13, this limestone, with the upper part of the Kinderhook group, forms a nearly perpendicular bluff more than a hundred feet high. The rock forming the upper part of this exposure is a massive gray limestone, with a few seams of chert. Strophomena analoga, Spirifer Grimesi and Euomphalus latus were obtained here. This rock is frequently intersected by fissures, which sometimes lead into caverns of considerable extent, and also afford an outlet to subterranean streams of water, which gush from the base of these bluffs in perennial springs. In the vicinity of Mason's Landing this limestone forms the upper bench in the high bluffs back of that point; and the beds of the small streams are filled with fragments of chert, derived from this formation by the decomposition of the calcareous portions of the mass. These cherty masses often afford delicate and beautiful casts of the crinoids and other characteristic fossils of this formation. Kinderhook Group. This group forms the base of the lower Car- boniferous limestone series in this portion of the State, and rests directly upon the Devonian shales. In this county it consists of thin-bedded, ash-colored, impure earthy limestone, with some massive layers of dolomitic limestone in regular beds. The shaly portions contain nodules of calcite, resembling geodes, which are coated with a very thin outer crust of chalcedony. About four miles below JEESEY COUNTY. 37 Grafton, this group measures about a hundred feet in thickness. The lower part consists of thin beds of impure cherty limestone, of a brownish-gray color, which contain the nodules of calcite above mentioned; and this is overlaid by a regularly bedded brown dolo- mitic rock, from fifteen to twenty feet in thickness; and this is again overlaid by ash-colored cherty beds, which pass upward into the overlying Burlington limestone, with no well-defined line of demarcation between them. The arenaceous beds, so characteristic of this group at the typical locality, as well as at other more north- erly points, are here replaced by calcareous strata. A few fossils were obtained from this group in the vicinity of Grafton, among which were Spirifer Vernonense, Athyris Prouti, .Strophomena analoga, Productus semireticulatus, and several species not yet determined. The outcrop of this formation is confined to the vicinity of the river bluffs ; and from Otter creek to the Macoupin there is a con- tinuous exposure of this group at the base of the bluffs, wherever the beds are not covered by a talus from the overlying limestone. The slates and shales that form the lower division of this group are represented in this county by from twenty to thirty feet of green shale, including, at some localities, a bed of black bituminous shale or slate, from which fact it is often supposed to contain coal, and much labor has been expended in the search for it at several points in the county. These explorations have generally been under- taken by the advice of those professedly acquainted with coal mining, who, having learned in the prosecution of their labors as coal miners, that black slates are usually associated with the coal seams, are nevertheless quite ignorant of another and equally im- portant fact, namely, that bituminous slates are not always associ- ated with bituminous coal, and sometimes do not even belong to the Coal Measures, as is the case with the slate now under consideration. Hence, these slates are known in mining parlance as "coal blos- som" ; and miners are always found that are ready to recommend a search for coal wherever beds of this kind appear, utterly regardless of the geological horizon to which they belong. This has resulted in the useless expenditure of more money, in nearly every county where these shales are exposed, than a complete scientific survey of the county would have cost. The bituminous slates and shales of the older systems can only be distinguished from those of the Coal Measures by a careful examination of the strata associated with them, a work which ordinary coal miners are in no way qualified to perform, and hence their judgment is not to be relied on. 38 ECONOMICAL GEOLOGY OF ILLINOIS. The outcrop of this formation in this county is confined to the river bluffs between Grafton and Otter creek, extending up the valley of the last named creek for about two miles. Nodules of iron pyrites abound in the shales at some localities ; but they afford no material of value for economical purposes, and in this county have thus far afforded but few fossils. Hamilton Limestone. Below the shales above named, and resting upon the Niagara limestone, we find a thin bed of earthy, brown limestone, from eight to fifteen feet in thickness. The rock appears quite massive in newly opened quarries ; but on exposure at the surface it splits into thin shelly layers, and hence will not prove to be a reliable building stone. At some localities the bed has some- what the appearance of a hydraulic limestone ; but its value in this respect has not been thoroughly tested. It is well exposed in the town of Grafton, where, by an undulation of the dip, the bed is brought down to the level of the town, though occupying a much higher position both above and below. We found in the beds at this locality Strophomena fragilis, Atrypa reticularis, and joints of crinoidea, with some fish remains. A thin layer of shaly limestone, at the junction of this bed with the Niagara limestone, is filled with sili- cious corals belonging to the genus Cystiphyllum; but their specific characters have not yet been determined. About a mile back of Mason's Landing, this bed is exposed near the place where the attempt was made to find coal in the overlying shale. It is here only about eight feet in thickness, and presents the same appear- ance as at Grafton. Just below the mouth of Otter creek it is found exposed, forming the base of the bluff, and is here about fifteen feet in thickness. The beds at this point appear to stand exposure better than at the other localities, mentioned ; and they may afford some good building stone. They are here overlaid by about four feet of brittle, bluish-gray, or dove-colored limestone, that resembles in some respects the Lithographic limestone of the Missouri Report ; and, if they represent that rock, the black slate must be wanting at this point. Niagara Limestone. This important division of the upper Silurian system is well exposed in this county, forming a considerable por- tion of the river bluffs from a point about a mile below Grafton to Otter creek, where it disappears with a north-easterly dip below the surface. It has a thickness in this county of about one hundred and twenty feet, and is a buff -colored dolomitic limestone, in regular beds, which vary in thickness from four inches to three feet. The quarries in the vicinity of Grafton present a perpendicular face of JERSEY COUNTY. 39 this rock, about forty feet in height, embracing the upper part of he formation. The rock is even-textured, cuts easily when freshly quarried, but hardens on exposure, and is remarkably free from chert or other silicious material. Mr. PEATTEN'S analysis of this rock gave the following result : Carbonate of lime 50.15 Carbonate of magnesia 42.20 Peroxide of iron and alumina 2.10 Insoluble matter 5.15 Loss 40100.00 It is undoubtedly the exact equivalent of the "Joliet limestone," and in its general character and appearance corresponds very nearly with the buff-colored beds at that locality. The color of the rock is much more uniform in this county than at Joliet; and it does not present those alternations of buff and gray which charac- terize the different strata at more northern localities; and, as a reliable building stone, it is not surpassed by anything at present known in the Mississippi Valley. Fossils are not very abundant in it; but the quarries at Grafton afford Calymene Niagarensis, Lituites Capax, and Orthoceras annulatum? The outcrop of this formation is confined to the bluffs of the Illinois and the Mississippi in this county, nowhere appearing at the surface at any considerable dis- tance from the rivers. Cincinnati Group. The lower Silurian system is only represented in this county by the shales of the Cincinnati group, and about forty feet of the upper part of the Trenton limestone, which appear at only a single locality, about five miles above Mason's Landing, on the northeast quarter of section 9, township 6, range 13, where the Cap au Ores axis crosses the Illinois river. Owing to. the soft argillaceous character of the shales at this locality, they are no- where well exposed, but are usually covered up by the debris along the base of the bluffs, exhibiting only at intervals slight exposures of a light-gray, shaly clay, somewhat resembling the fire-clays of the Coal Measures. Their outcrop extends from the point above named to within about a mile of Coon creek, where they dip below the surface. This group contains some plates of dark-brown sand- stone, and nodules of iron pyrites. Its thickness we were not able to determine accurately by measurement, but have estimated it ap- proximately at from forty to fifty feet. No fossils were found in it in this county, and no indications were seen of the presence of the bituminous shales and slates which are characteristic of it at more 40 ECONOMICAL GEOLOGY OP ILLINOIS. northern localities. It appears to be mainly a light, bluish-gray clay shale, that weathered on exposure to a pure clay, apparently suitable for potters' use. Trenton Limestone. This formation only appears above the surface at one point, which is on the northeast quarter of section 9, town- ship 6, range 13, where about forty feet of the upper part of it is exposed. The rock is thin-bedded, compact, and of a light-gray color, splitting easily with an uneven cleavage. The rock has been quarried here, at Williams' lime-kiln, for lime-burning, for which it is tolerably well adapted, though by no means equal to the St. Loui& limestone, which is quarried for the same purpose on the other side of the axis, a half mile below. This outcrop of Trenton limestone is on the northerly side of the axis, and the rocks dip to the north- east; but, immediately below, the dip is reversed, and the Niagara limestone and the whole series of Devonian and lower Carboniferous limestones are thrown down in a distance of half a mile. The two lime-kilns, situated less than half a mile apart, are thus supplied by two distinct limestone formations, which, if remaining in their normal position, would be separated from each other by a thickness of at least eight hundred feet of strata; but here, by the sudden dislocation and downthrow of the beds, are brought in close prox- imity to each other. This axis of disturbance gives origin to a double series of bluffs, which extend from this point nearly to Mason's Landing, with a deep valley between, with the strata on either side dipping in opposite directions. All the ISilurian and Devonian strata that appear above the surface in this county have been elevated by the disturbing forces that formed the axis above described ; and they soon pass below the surface, as the influence of this elevating movement diminishes in either direction. Economical Geology. Coal. Although there are three or four distinct seams of coal cropping out in this county, but one of them is mined to any con- siderable extent at the present time (1864). This is the No. 5 coal of the general section, and varies in thickness in this county from three to five feet. It is the equivalent of the lower seam in the old Pittsburg mines, in St. Clair county, and the lower seam on Hodge's creek, at the east line of Greene county. It affords a coal of fair quality, and is capable of yielding four million tons of coal to every section of land which it underlies. JERSEY COUNTY. 41 The upper seam we were not able to examine in a very satisfac- tory manner, but were informed that it was from two and a half to three feet in thickness, where it has been opened, and afforded a coal of fair quality ; but, in consequence of the shaly character of the roof, it has not been much worked, except along the outcrop of the seam, where the coal was dug in open trenches by throwing off the superincumbent clay and soil. In could be worked in the usual manner by drifting, but the entry would require thorough cribbing to support the roof. The middle or No. 5 seam has a good lime- stone roof, and consequently can be mined much more easily and safely than the upper seam. Below the middle seam are there from sixty to eighty feet of shales and shaly sandstones separating it from the lower seam, which appears to be the equivalent of coal No. 1, or possibly it may be even lower, and represent a Conglomerate coal. It affords a coal of rather inferior quality, owing to the sulphuret of iron which it contains ; and, since the opening if the upper seam, the lower one has been generally abandoned. These coal seams are mainly restricted to the eastern tier of townships in this county. Clays. As has already been observed in our remarks on the drift deposits of this county, a pottery has been established near Fieldon, the material for which is obtained from the plastic clay at the base of the drift, which answers tolerably well for the manufacture of a coarse quality of ware. But the clays that are usually found associated with the lower coal seams afford a much better material for the manufacture of potters' ware or fire-brick, and may yet be found in this county. Hydraulic Limestone. A bed of this useful material is found in the bluffs of the Piasa, intercalated in the lower part of the St. Louis limestone/ The bed is about eight feet in thickness, and is quarried by drifting into the face of the bluff. It is about forty feet above the Piasa; and the hydraulic rock is overlaid here by heavy beds of buff-colored magnesian limestone. Below the hydraulic rock, the beds become shaly, and pass downward into the calcareo-argillaceous shales of the geode bed of the Keokuk group. Smith's cement mill, erected at this point, has capacity to grind two hundred barrels per day. This hydraulic bed also crops out in the river bluffs, above the mouth of the Piasa, and may undoubtedly be worked at several localities, should the demand for it warrant increased facili- ties of manufacture. Quick-lime. All the main limestone formations in the county afford more or less material adapted to the production of lime, 42 ECONOMICAL GEOLOGY OF ILLINOIS. though the best article will probably be obtained from the Car- boniferous limestones. The compact bluish-gray beds of the St. Louis limestone, and the light-gray limestone of the Burlington series, afford an inexhaustible supply of the very best material for this purpose. Some of the beds of the Keokuk limestone on Otter creek may be used for this purpose, and will supply the local demand in that part of the county. Iron Ore. No indications of the existence of any extensive deposit of iron ore were observed, though there is a band of dark-red hematite occurring in the sandstone overlying the St. Louis lime- stone at Cooper's quarries. The ore appeared to occur only in nodules, and not in sufficient quantity to be of any value. It affords' however, some interesting specimens of this variety of ore. Although only seen at a single locality, it will no doubt be found at other points in the county occupying the same horizon. Building Stone. Of all the natural resources of this county, except coal, there is none that will eventually conduce more to its wealth and general prosperity than its unlimited supply of superior build- ing stone. Of the five important limestone formations in this county, all afford more or less building stone of good quality; while the Niagara limestone, the most important of all, will afford an inex- haustible supply, which, in point of quality, is not excelled by any- thing of the kind at present known in the Mississippi Valley. Its outcrop being entirely confined to the river bluffs, it can be easily transferred from the quarries to barges, on which it can be cheaply conveyed to any desired point on the Illinois or the Mississippi rivers. It is a regularly-bedded, even-textured, buff-colored dolomite, easily cut into any desirable form, and one of the most durable rocks in the State. It affords strata of every desired thickness, from four inches to three feet. The thinnest beds afford a good flagging-stone; while the thicker ones furnish dimension- stone of any desirable size. The. material for the old Lindell Hotel, in St. Louis, was obtained from the Grafton quarries, and it would hardly be an exaggeration to say that this bed of limestone, alone, will afford material enough in this county to build a continuous city from the mouth of the Illinois river to St. Louis. It is at least one hundred and twenty feet thick, and outcrops from Otter creek to a point about a mile below Grafton, where it finally dips below the river level and disappears. The Burlington limestone, which forms the entire bluff in the vicinity of Jersey landing, also affords an excellent building stone, and has been used for the construction of mills, ware-houses and JERSEY COUNTY. ' 48 dwellings at that point. It is nearly white in color, cuts easily, and is an excellent material for caps and sills, where a light-colored rock is desired. It is not as evenly bedded as the Niagara lime- stone and contains some seams and nodules of chert. The [St. Louis limestone affords an abundant supply of material for rough walls and heavy masonry, at all the localities where it outcrops in this country. On the Piasa, anywhere from the bridge on the Jerseyville and Alton road to the river bluffs, this limestone may be found, and will afford all the material for foundation walls and heavy masonry that may be needed for local use. The Keokuk limestone, in its outcrop on Otter creek, will also furnish some tolerably good building stone ; but it is generally unevenly bedded, and contains much cherty material. That part of the county lying east of Jerseyville is very poorly supplied with building stone ; the sandstones and thin beds of lime- stone belonging to the Coal Measures being the only rocks that out- crop in this part of the county. The shaly sandstones below the main coal seams crop out on the Piasa, in the southeast part of the county, and afford some material suitable for walling wells, etc., but too soft for heavy masonry. At J. Fink's quarries, on Phill's creek, northeast of Jerseyville, a similar sandstone is found, that answers very well for flag-stones and light walls. The brown Fusulina limestone, that crops out about a mile west of Brighton, is a very hard and durable rock, and will supply the local demand for culverts and foundation walls in the vicinity of its outcrop. Soil, Timber, etc. The topographical features presented by the uplands in this county are quite varied. Adjacent to the bluffs of the great rivers which form the southern and western boundaries of the county, and extending back for a' distance of from three to six miles, the surface is broken into steep ridges, which are separated by deep ravines. ' The .soil is a dark-colored loamy clay, such as is everywhere characteristic of lands underlaid by the Loess, but is admirably adapted to the growth of fruit, and might be made a pomological paradise, under the management of those who know how to improve the favorable conditions which the hand of nature has so bountifully supplied. This portion of the county was origi- nally covered with a heavy growth of timber, consisting of the usual varieties of oak, hickory, wild- cherry, etc. Between Jerseyville and Fieldon the surface is comparatively level, and the timber consists of the usual varieties' of oak, hickory, ash, elm, linden, cherry, honey-locust and black walnut; and the 44 ' ECONOMICAL GEOLOGY OF ILLINOIS. valleys of the streams afford, in addition to these, cottonwood, syca- more, white and sugar maple, coffee-nut, hackberry, pecan and white walnut. That portion of the county east of Jerseyville is underlaid by the Coal Measures, and is comparatively level, except the region trav- ersed by the Piasa, where the surface is broken into sharp ridges, some of which are a hundred feet or more above the bed of the creek. The prairies are generally small, and are restricted to the northeastern part of the county. They are covered with the deep black soil so characteristic of the prairies in Central and Northern Illinois ; and in their productive qualities they are not surpassed by any other portion of the State. As an agricultural region, this county ranks among the best ; and, taking into the account its prox- imity to the great rivers, its prospective railroad facilities, its varied and rich mineral resources, it must commend itself at once to the attention of those seeking a home in this State, as one of the most attractive and promising locations to be found. Fine springs of water are abundant in the limestone region; and good wells are obtained on the prairies at a depth of from twenty to forty feet. It is one of the finest wheat-growing counties in the State; and, from the varied character of the surface, it is adapted to the growth of all kinds of cereals and fruits that can be grown in this latitude. The broken lands in the vicinity of the river bluffs are well adapted to grape culture : and, if in the hands of skillful vine-growers, could be made to yield a more liberal return for the labor required to cultivate them than can be obtained from the richest prairie lands in the county, planted with the common cereals grown in this climate. I cannot close my report on this county without acknowledging my obligations to Dr. R. D. FARLEY and Mr. WILLIAM McADAMS, Jr., for valuable assistance and important information in 'regard to some of the most interesting and important points in the county, and also for many acts of personal kindness and hospitality which I received at their hands while prosecuting my labors in this county. The State Cabinet is also indebted to them for several rare specimens, which they generously donated from their private cabinets. CHAPTER III. GREENE COUNTY. This county lies immediately north of Jersey, which forms its southern boundary, and is bounded on the west by the Illinois river, on the north by Scott and Morgan counties, and on the east by Macoupin county. It has a superficial area of about fifteen town- ships, or five hundred and forty square miles. It is well timbered and well watered, having, in addition to the river which forms its western boundary, Apple and Macoupin creeks, which, with their tributaries, traverse the county from east to west. Fine springs are also abundant along the river bluffs, and throughout the limestone region generally; and good wells are usually to be obtained on the uplands, at depths varying from thirty to forty feet. The surface of the county is generally rolling; and the western portion, in the vicinity of the river bluffs, is quite broken and hilly, the valleys of the small streams being excavated to the depth of from one to two hundred feet below the general level of the uplands. In the central and eastern portions of the county the depressions of the valleys are considerably less, seldom exceeding fifty or sixty feet below the general level. The prairies are small ; and the county has an abundant supply of timber, of the same varieties observed and noticed in the report on Jersey county. The bluff lands are well adapted to the cultivation of fruit, as well as wheat and the cereals generally; and, in point of soil and agricultural capacities, this county is not much behind the adjoining county of Jersey ; and the general remarks made with regard to the latter county, may be ap- plied with equal propriety to this. The completion of the St. Louis, Jacksonville and Chicago Rail- road through this county, gives additional facilities for the cheap and rapid transportation of its agricultural products to market, for 46 ECONOMICAL GEOLOGY OF ILLINOIS. which it has heretofore been entirely dependent on the navigation* of the Illinois river ; and it will add materially to the value of the farm- ing lands in the county, and to the general wealth and prosperity of its inhabitants. General Geology of the County. The geological features of this county are by no means so varied as those presented in the adjoining county of Jersey, for the reason that the disturbing influences that have elevated the Devonian and Silurian beds above the surface, in that county, did not extend into this ; and consequently we find no beds exposed here below the lower Carboniferous limestones. The following vertical section of the several formations in the county will illustrate their general thickness and relative position: Quaternary deposits, alluvium, loess and drift 100 to 120 feet Coal Measures 150 to 160 St. Louis limestone 8 to 40 Keokuk limestone 100 to 125 Burlington limestone 120 to 150 Kinderhook group (partial exposure) 50 to 60 Alluvium. The principal alluvial deposits in this county are those forming the bottom lands on the Illinois river, comprising a belt from three to five miles in width, and extending the whole length of the county from north to south. These lands are exceedingly fertile, and are among the most valuable and productive farming lands in the county. The greater portion of these bottom lands are prairie, sufficiently elevated to be susceptible of cultivation, and exceedingly productive. Adjacent to the river bluffs they are ele- vated entirely above high-water mark, and are not subject to over- flow from the annual river floods. Belts of heayy timber occupy some portions of these bottom lands, and skirt the small streams by which they are intersected. The varieties of timber observed in this county are the same that have been enumerated in the preceding chapter as occurring in Jersey county. Loess. This formation is usually confined to the vicinity of the river bluffs, which it caps to the depth of from forty to sixty feet, and gives origin to the bald grassy knobs, which form so notable a feature in the topography of the bluffs, both on the Illinois and the Mississippi. It is largely composed of beds of marly sand, which sustain a thick growth of wild grass, and occasionally a stunted growth of oak. It is unconformable to the drift clays below it, and presents its greatest thickness immediately at the river bluffs, grow- GREENE COUNTY. 47 ing thinner toward the highlands of the adjacent region. It has been formed in the quiet waters of the lakes which once occupied the present valleys of the Illinois and the Mississippi rivers. These marly beds of loess form an admirable sub-soil, being suffi- ciently porous to allow a thorough drainage ; and, where they under- lie a gently rolling or tolerably level surface, they form a quick, warm and very productive soil. Drift. Soft fine sections of drift were seen in the bluffs of Bear creek, below Blanchard's coal bank, of forty to fifty feet in thick- ness. The lower part was composed of bluish-colored clays, with small pebbles, and the upper part of the common reddish-brown clay, so generally characteristic of this formation. Large boulders of metamorphic rocks are not so abundant in the drift of this region as in many other portions of the State, but a few were seen of moderate size, composed of green-stone, porphyry and granite, giving unmistakable evidence of their northern origin. Specimens of drifted copper and galena are also occasionally found in the clay and gravel beds of this region, which cover the whole surface of the county, except the valleys of the streams. These have been transported also from the north the copper from Lake Superior, and the galena from the lead region of northern Illinois or Wisconsin, and were transported at the same period and by the same agency that brought the boulders of metamorphic rock. Coal Measures. The Coal Measures of this county comprise about a hundred and fifty feet in thickness of sandstone shales, and thin bands of limestone, including three seams of coal, and comprise all the strata from the horizon of Coal No. 5 to the base of the meas- ures, as they are developed in this portion of the State. The sub- joined general section, compiled from many local sections in various parts of the county, will show their general thickness and relative position : Compact brown limestone 2 to 4 feet Bituminous shale 1 Coal No. 5 6 Shaly clay and nodular limestone 3 to 4 Shale 15 to 20 Bituminous shale 2 to 3 Coal No. 3 2 to 3 Arenaceous shales and sandstone 25 to 30 Bituminous shale, passing to Coal No. 2 2 to 3 Sandstone and shale 40 to 50 Coal Tulison's and Nettle's Coal No. 1 2 to 3 Nodular steel-gray limestone, sometimes replaced with fire-clay, as at Tuli- son's 4 to 6 Shale and sandstone, passing locally into conglomerate 15 to 20 153 feet 48 ECONOMICAL GEOLOGY OF ILLINOIS. The only outcrop of coal No. 5 that was met with in this county is^ on the northeast quarter of section 36, township 10, range 10, just on the county line between Greene and Macoupin, in the bluffs of Hodges creek. This bank was owned and worked in 1864 by Thomas Kice, and the seam is here very variable in its thickness, ranging from four to seven feet. The upper part of the seam is considerably mixed with sulphuret of iron, and is only fit for steam purposes; but the middle and lower portions afford a good smith's coal. The seam at this locality dips to the eastward ; and this may probably be considered as its most westerly outcrop. There are only a few inches of shaly clay separating this seam from the nodular argilla- ceous limestone below, exhibiting here the phenomenon of a heavy seam of coal directly inclosed between beds of marine limestone. The nodular limestone below the coal abounds in fossils at this locality, among which a massive coral, the CJuetetes milliporaceous, is most conspicuous. This coral is generally hemisperical in form, and often attains a diameter of six to twelve inches. The limestone also contains many univalve shells belonging to the genera Naticop- sis, Pleurotomaria, Loxonema, etc. Several species of these beautiful shells, from this locality, are figured and described in the second volume of the original report. The limestone which forms the roof of the coal is a compact bluish-gray rock, which weathers, on ex- posure, to a rusty-brown color, and contains Productus longispinus, Spirifer lineatus, Fusidina, and joints of Crinoidea. Below this coal there is another seam that outcrops on the creek in this vicinity. It has not yet been worked to any extent, and no good exposure of it was seen, but it is reported to be about two feet in thickness. Bassett's coal, on the southwest quarter of section 27, township 10, range 11, is about eighteen inches in thickness ; and the coal is overlaid, first, by three or four feet of bituminous shale, and this by a limestone septaria, four feet or more in thickness. The coal is underlaid by a blue clay shale, from four to six feet thick, and this by a brown sandy shale, passing into sandstone, which outcrops down the creek for a distance of half a mile or more, and shows a thickness, altogether, of twenty-five or thirty feet. This seam prob- ably overlies the coal at Tuilson's, on Wolf Eun, as well as that on Birch creek; but, as they were not met with on the same stream, that point could not be positively determined. I am inclined to believe that it represents coal No. 2 of the general section. The coal in this seam appears to be of good quality, but it is too thin to be profitably mined at the present time. At many points there GREENE COUNTY. 49 is a heavy bed of sandstone intervening between this seam and the coal on Brush creek; and a similar bed, though perhaps a higher one in the series, is well exposed in the bluffs of Macoupin creek, at Eock bridge. The exposure here is from thirty-five to forty feet in thickness, the lower part consisting of blue sandy shales, which are overlaid by a massive brown sandstone, passing upward into a brown sandy shale. The sandstone is partly concretionary in structure, the concretions being quite hard, and forming a durable building stone. On Birch creek a similar sandstone is well exposed, overly- ing coal seam No. 1, with a thickness of twenty-five to thirty feet. Nettle's coal-bank is on the northeast quarter of section 25, town- ship 12, range 11, about eight miles northeast of Whitehall. The coal averages about three feet in thickness, and is overlaid by from three to five feet of bituminous shale, which forms a good roof to the coal. Above the shale there is a bed of massive sandstone, twenty feet or more in thickness, similar to that at Rock bridge. Under the coal there is a bed of shaly clay, not more than a foot or two in thickness, which rests upon a hard, steel-gray, nodular limestone, about four feet 'thick. These beds outcrop along the creek for a distance of about three miles above Nettle's place, the fall of the creek being just about equal to the dip of the coal, and in the same direction, which is to the southeast. On Wolf Eun, about a mile and a half east of Whitehall, a seam of coal outcrops along the creek for a distance of a mile or more, and has been opened at several points. It is from two feet to two and a half in thickness, and is a clear, bright coal, breaking in regularly shaped blocks, and quite free from sulphuret of iron. It is overlaid by about two feet of bituminous shale, which passes upward into a blue clay shale, which is overlaid by sandstone. Below the coal there is an excellent bed of fire-clay, from eight to ten feet thick. The upper openings on this creek are on the lands lately owned by David Eankin, and the lower one is on the lands of Isaac Tulison. On the southeast quarter of section 36, township 11, range 12, about four miles northeast of Carrollton, a coal seam has been opened on the west fork of Whitaker's creek, which, with the asso- ciated rocks, forms the following section : Coal Measures Brown sandy shale 10 to 12 feet Bituminous shale 2 Coal l% " Shaly clay, passing downward into sandy conglomerate 10 to 15 ' * 4 50 ECONOMICAL GEOLOGY OF ILLINOIS. Band of iron ore 1?2 feet Hydraulic limestone 4 to 6 " Keokuk limestone 15 to 20 The beds above the band of iron ore in this section belong to the Coal Measures, and those below to the lower Carboniferous lime- stone. It will be observed, in this section, that the St. Louis lime- stone, upon which the Coal Measures usually rest in this county, is not represented, unless it be by the bed of hydraulic limestone. The Keokuk limestone is well marked, presenting the usual charac- teristics that distinguish it at other localities. The iron ore above the hydraulic limestone is an earthy, brown hematite of good quality. The coal seam is only about eighteen inches in thickness, and the work of mining it appeared to have been temporarily suspended. This coal has been opened on the east fork of Whitaker's creek, and also on Bear creek, on Mr. Blanchard's place, about a mile and a half above the mouth of the creek. Blanchard's coal bank is on the northwest quarter of section 14, township 11, range 11. The coal varies in thickness from two to three feet, and is overlaid by bituminous shale and massive sand- stone. This seam appeared to be the same at Nettle's coal, on Birch creek. A mile and a half below Blanchard's the St. Louis limestone is to be seen in the bluffs of the creek ; but the interven- ing beds between the coal and the limestone are not exposed. In sinking the well for the steam mill at Carrollton, a thin seam of coal, about six inches thick, was said to have been passed through at a depth of about seventy feet below the surface. Although the Coal Measures underlie nearly all of the eastern half of the county, they comprise only the horizon of the lower coal seam, over a con- siderable portion of this area; and, along the extreme western bor- ders of the coal field, even this is too thin at many localities to be worked to advantage, and the eastern range of townships must be mainly relied on for a supply of coal. The measures in this county comprise the whole range of the productive Coal Measures, as they are developed in this portion of the State ; but the main seam, No. 5, only extends a little over the eastern line of the county, and con- sequently underlies but a very small area in this county, while the lower part of the measures, which underlie all the eastern portion of the county, only have two of the four lower seams developed, and these range in thickness from eighteen to thirty-six inches. Hence Greene county is not as well supplied with coal as either Jersey or Macoupin ; and the principal deposits are confined to the eastern portion of the county. The seam at Nettle's mine, on Brush creek, GREENE COUNTY. 51 and at Blanchard's, on Bear creek, I regard as probably the same as the Exeter coal, in Scott county, and Tulison's bank, two miles northeast of Whitehall, may be referred to the same horizon. Bur- rows' coal probably holds a higher position, and perhaps represents either No. 2 or 3 of the general section of the Coal Measures in Central and Northern Illinois. St. Louis Limestone. This formation is quite variable in this county, both as regards its thickness and its lithological characters. On Link's branch, south of Carrollton, and about a half mile east of the State road from Carrollton to Jerseyville, a fine quarry has been opened in this limestone, on the lands of Mr. Joseph Stohr. The thickness of the rock at these quarries is about fifteen feet ; and the lower ten is a heavy bedded magnesian limestone, some of the layers being from two to three feet thick. The prevailing colors are light yellowish-gray and brown; and these colors often replace each other in the same stratum. The rock is even-textured, free from chert or other siliceous material, and dresses easily ; and these quarries afford most of the cut stone used at Carrollton. The lowest strata seen at these quarries appeared to be a hydraulic limestone, and was about eighteen inches thick. At the crossing of the State road, a half mile further up the creek, the rock is not so even- textured, some of the strata being too hard to dress readily, and others too soft to stand exposure to the atmosphere. The whole thickness of the beds exposed, from the State road to Stohr's quar- ries, may be estimated at from twenty-five to thirty feet. In the upper part of this group, near the State road, there is also another stratum of what appeared to be a hydraulic limestone, about two feet thick. On the road from Carrollton to Turpin's mill, this limestone is found outcropping in the beds of the small creeks that empty into the Macoupin. Turpin's mill is on section 16, township 9, range 11 ; and the St. Louis limestone is found well exposed on a small branch about a quarter of a mile west of the mill. The lower part of the bed, as it appears at this locality, is a brown arenaceous limestone, while the upper is of a gray and mottled color, and suf- ficiently pure to be burned for lime, though not a very good material for that purpose. The entire thickness of the beds exposed here is only about fifteen feet. At Thompson's mill, on the northeast quarter of section 10, town- ship 11, range 11, there is an exposure of about twelve feet of this formation. The upper four feet is a brown magnesian limestone, and the lower eight feet an earthy, grayish-brown hydraulic lime- 52 ECONOMICAL GEOLOGY OF ILLINOIS. stone, exactly resembling in appearance the hydraulic layers of this formation at other localities. This is the thickest bed of this kind of rock found in the county; and, if it should prove on trial to be as good a hydraulic rock as its appearance would indicate, it will become valuable for the manufacture of cement. It is no doubt the equivalent of the hydraulic limestone noticed at the coal mine on the west fork of Whitaker's creek, and is here nearly twice as thick as at that locality. Fossils are quite scarce in this formation, at nearly every locality examined in this county. Some interesting forms of Bryozoa were obtained at the quarries on Link's branch, and we saw, in the cabinet of Dr. FARLEY, of Jerseyville, a fine specimen of Conularia, probably C. Missouriensis, that was found at this locality. - V*v Keokuk Limestone. This formation, with the overlying St. Louis limestone, occupies a belt immediately beyond the western borders of the Coal .Measures, and intervening between them and the Bur- lington limestone in the vicinity of the river bluffs. This belt is from three to four miles in width ; and the Keokuk limestone, which forms the greatest portion of it, outcrops on the tributaries of Macoupin and Apple creeks, and on the last "named creek itself, a half mile below the bridge, on the main road from Carrollton to Whitehall. On the small creek, a half mile south of Whitehall, the upper part of the Keokuk limestone is found outcropping for a distanc^ of a mile and a half or more on either side of the creek. The rock is here a thin-bedded, cherty, gray limestone, with thin partings of calcareo-argillaceous shale. It seldom affords strata more than six inches thick, and is therefore not a desirable building stone, except for light walls. It affords some characteristic fossils at this locality, among which are Archimedes Owenana, Platyceras equilatera, Agari- cocrinus Americanus, Productus punctatus, Spirifer cuspidatus and S. Keokuk. The fossils of this formation are not so numerous or so well preserved at the localities examined in this county as they are in the same beds in Jersey county. On the west fork of Whitaker's creek, these same beds are ex- posed between the coal bank and the mouth of the creek, and afford the same varieties of fossils obtained in the vicinity of Whitehall. On Apple creek, a short distance below the bridge on the Carrollton and Whitehall road, the lower beds of this limestone are exposed, affording layers from twelve to eighteen inches thick. No point was found in the county where the whole of this formation could be seen in a single section ; and, for a general description of its char- GKEENE COUNTY. 53 acteristic features, as well as the determination of its thickness, we have relied upon the results of local examinations of such portions of the formation as could be found exposed in different parts of the county. We have estimated its thickness, approximately, at one hundred to one hundred and twenty-five feet; but it may be some- what greater, even, than that. Burlington Limestone. The outcrop of this formation is confined to the western part of the county. It forms the main portion of the river bluffs throughout the whole extent of the county, from north to south, and extends eastward from the bluffs, forming a belt from three to four miles in width. At the south line of the county, where Macoupin creek intersects the river bluffs, the lower part of this limestone, about seventy feet in thickness, forms the upper part of the bluff, and is underlaid by fifty-four feet of the ash-colored shaly limestones of the Kinderhook group. From this point to the north line of the county, this limestone is seen in a continuous exposure, except where intersected by the valleys of the small streams ; and it often presents mural cliffs of limestone along the face of the bluffs, from seventy-five to a hundred feet in height. At James J. Eldridge's place, the limestone measures a hundred feet in thickness above the road at the foot of the bluff, and is capped by a mound of loess sixty feet high; and the bluffs very generally culminate, in this vicinity, in bald knobs, covered only with grass, giving a very picturesque outline to the landscape. The limestone at Eldridge's place is a light gray crinoidal rock, in quite regular beds, with comparatively but little cherty material, and forms an excellent building stone, which is extensively used not only at this locality, but by the wealthy farmers occupying the bottom lands at the foot of these bluffs throughout the county, for dwellings and barns, and also for fences. About half a mile below the county line between Greene and Scott, the limestone bluffs are about one hundred feet high, and are capped with forty feet of loess. At this point there is a bench of brown limestone, projecting a few feet beyond the face of the bluff, and only a few feet above the base, that is covered with rude figures cut upon the surface of the limestone by some of the aboriginal inhabitants of this country. Among these figures are the outlines of a human foot, and also that of a bear, several that were evidently intended to represent the tracks of birds, and others that do not appear to represent any nat- ural object, but seem rather designed to record, in hieroglyphics, some historic or mythological events. These figures were cut upon the surface of the stone with some hard instrument, to the depth of 54 ECONOMICAL GEOLOGY OF ILLINOIS. perhaps one-sixteenth of an inch. The surface of the stone on which they were engraved, has been worn almost as smooth as glass, probably by the tread of human feet. The bluffs of the Illinois and the adjacent bottoms appear to have been favorite resorts of some of the primeval races ; and their rude antiquities, consisting of stone axes and knives, discs, flint arrow- heads, and an instrument resembling a mason's plummet, made apparently from the compact iron ore of the Iron Mountain in Missouri, are quite common in the counties of Greene, Jersey and Calhoun. Fossils are not very numerous in the Burlington limestone, at the localities we examined in this county ; but the following species were obtained: Spirifer Grimesi, S. Forbesii, Aihyris incrassata, A. lamel- losa, Productus punctatus, and Actinocrinus concinnus. Kinderhook Group. The upper half of this formation, including a thickness of about fifty feet, may be seen at the point where the Macoupin intersects the river bluffs ; and this is the only exposure of the bed that we have met with in the county. So far as could be seen, it consisted of ash-colored shales and shaly limestone, and afforded no fossils at this locality. Above this point, its outcrop along the bluff is hidden by the talus from the overlying beds. Economical Geology. Coal. About one-third of the entire surface of the county is under- laid by the Coal Measures ; and they include the horizon of three or four coal seams, though but two of these appear to be mined at the present time to any considerable extent. The upper one, No. 5, is only found along the east line of the county, on Hodges creek. It underlies but a very limited area in this county, and the exposures above named are probably nearly or quite on the western limit of its outcrop. We did not see it on Apple creek, but its line of out- crop would indicate that it might be found on that stream, in the vicinity of Athens. The two lower eams are comparatively thin, and nowhere exceed about three feet where they have been examined in this county. No. 5 varies in thickness in this county from four to seven feet, while the lower seams, of which there are three, vary in thickness from one and a half to three feet. The two lower seams will probably be found to underlie nearly all the eastern portion of the county; and they will afford an abundant supply of coal for home consumption. The seam that outcrops on Birch creek is probably JERSEY COUNTY. 55 the same as that on Tulison's land, near Whitehall ; and it may be mined at almost any point in the eastern part of the county, "at a depth varying from fifty to one hundred and fifty feet below the surface. Where it is desirable to mine it at a point where it does not outcrop at the surface, a boring should first be made to ascer- tain the thickness of the coal and its depth below the surface ; and, when these points are determined, an exact calculation can be made of the expense of opening the mine, and the amount of coal it will afford to a given area. The expense of boring ought not to exceed two dollars per foot for the first one hundred and fifty feet. On Wolf Eun and on Birch creek, where the lower seam is exposed, it will average two feet and a-half in thickness, and will yield two and a-half million tons of coal to the square mile. It is the same as the Exeter coal, in Scott county, and the coal it affords is gen- erally better than the average quality, being quite as free from sul- phuret of iron, in this county, as No. 5. The seam at Bassett's, on the southwest quarter of section 27, township 10, range 11, appears to be of a local character, and can not be relied on as a productive bed, over a large area of surface. It was not met with anywhere else during our examinations of the county. Clays. The best clay for the potter's use, and for fire-brick, is the bed under the coal seam on Wolf Eun. At some points this clay is from eight to ten feet thick, and outcrops at the surface, at many localities, from one and a-half to three miles from Whitehall. The thickness of this bed, and its proximity to the railroad, make this one of the most valuable deposits of potters' clay known in the State ; and the near proximity of excellent coal, which may often be mined in the same drift with the clay, makes this one of the most desirable points for the manufacture of fire-brick or pottery, on a large scale, that can be found in the State. At Blanchard's mine no exposure of the clay under the coal is to be seen ; and on Birch creek the coal-seam is underlaid by limestone, below which the beds were not seen ; but in the vicinity of Winchester, and at some other localities in Scott county, the limestone below this coal is underlaid by a thick bed of nearly white clay, almost exactly like that east of Whitehall; and it is quite probable a similar clay may be found underlying the limestone on Birch creek. Paint Clays. At Mr. Charles J. Carter's place, two and a-half miles southwest of Woodville, there is a local deposit of paint clays underlying the true northern drift, and yet bearing no apparent lithological relation to the rocks on which they rest. The deposit at this point consists of red, yellow and white clays, attaining a thick- 56 ECONOMICAL GEOLOGY OF ILLINOIS. ness altogether of about eight feet, and they are intercalated between the boulder drift and the geodiferous shales of the Keokuk lime- stone. In composition they are quite unlike any of the rocks with which they are now associated, and they have probably been derived from shaly beds of stratified rocks more recent than the lower Carbonif- erous limestone on which they rest. The upper part of the deposit is a bed of white clay from four to six feet in thickness, and below this, beds of red and yellow clays occur. They have been thoroughly tested by Mr. Carter and others, and have proved to be well adapted to form a cheap paint for outside walls, and a number of different shades of color may be produced by adding a small and variable amount of Prussian blue. Similar deposits of paint clays occur in various portions of the State, though of limited extent, and have all probably been derived from some common source. It is quite probable that they have originated from outliers of cretaceous shales, that, anterior to the Drift epoch, occupied depressions in the older rocks far beyond the present boundaries of that formation in the west, and, I have no doubt, once covered considerable areas in this State, and were broken up and partially carried away by erosive agencies anterior to the deposit of the boulder drift, while the residuum was re-de- posited in the depressions of the limestone floor in the form of fine siliceous clays. This theory will also explain the occurrence of cretaceous fossils in the superficial deposits of this and the adjacent States, such as sharks' teeth, fragments of Ammonites, Belemnites, and other cretaceous forms which are sometimes met with in our gravel beds, or in the alluvial deposits of the streams, in such a state of preservation as would preclude the assumption that they had been transported from remote points by the ordinary drift agencies of ice and water. These deposits of paint clays are of considerable local value, as they furnish a cheap and durable paint for common use. Hydraulic Limestone. The St. Louis limestone affords some layers that seem to possess hydraulic properties, at several localities in this county, though they are generally rather too thin to be of much value at the present time. The thickest bed seen in the county is at Thompson's mill, on Apple creek, where it is about eight feet in thickness. This locality would afford a sufficient amount of material to justify the erection of a cement mill at this point, should the rock prove, on trial, to be as well adapted to this purpose as its appearance would indicate. JERSEY COUNTY. 57 Iron Ore. On the west fork of Whitaker's creek there is a seam of iron ore underlying the coal at that locality, about eighteen inches in thickness. The ore is a hematite of a dark brick-red color, and appears to be of a good quality. Coal and limestone, for reducing it to metallic iron, are abundant in the vicinity of the ore. Limestone for Lime. The best material for this purpose, that we met with in this county, is that afforded by the light gray semi- crystalline beds of the Burlington limestone, along the river bluffs. Some of these are a nearly pure carbonate of lime, and are not sur- passed for this purpose by any limestone in the county. The lowej part of the. Keokuk limestone, as it appears below the bridge on Apple creek, will afford a very good limestone for this purpose ; but the St. Louis group, which usually affords the purest limestone of all, affords no material adapted to this purpose at any of the local- ities we were able to examine in this county. Building Stone. All the principal limestone formations in this county afford good building stone for ordinary purposes; and some of them afford a superior article, suitable for cut- stone work and ornamental architecture. The most abundant supply, as well as the finest material of this kind, will be furnished by the Burlington limestone, which outcrops in the vicinity of the river bluffs. The rock is tolerably even-bedded, in strata varying from six inches to two feet in thickness, and can be very easily and cheaply quarried ; so that it is now used, not only for all the ordinary purposes for which a building stone is required, but also for fencing the farms along the foot of the bluffs. Several elegant farm-houses have already been built in this county from this material ; and, as the wealth of the country increases, something like a correct taste in architecture will obtain among the people, and a desire for more substantial and elegant buildings will be the result. This will give increased value to our supplies of fine building stone ; and quarries that are now reckoned of little value to the owners, will eventually become sources of wealth to an extent that cannot at present be realized. The St. Louis limestone will perhaps rank next in value for sup- plying the wants of the citizens of this county with good building stone. The quarries on Link's branch, near Carrollton, are capable of supplying the wants of that town and the surrounding country. The rock obtained at this locality is a yellowish-gray or brown mag- nesian limestone, soft enough to be cut with facility, when freshly quarried, and makes a fine building stone, either for cut-work or for heavy walls. Some of the beds are thick enough to furnish dimen. 58 ECONOMICAL GEOLOGY OF ILLINOIS. sion-stone of a large size. At the present time (1864) the demand for this stone is limited to the vicinity of the quarries ; but, when the railroad is completed to this point, this rock may be profitably furnished to distant and less favored localities. This bed will fur- nish a good material for heavy walls, at every locality where we saw it exposed in this county. The Keokuk limestone will also furnish a very good building stone, wherever the lower part of the bed is found exposed. This portion of the bed affords layers of light bluish-gray compact limestone, from six inches to a foot in thickness, that may be used for all the ordinary purposes for which material of this kind is required. In the upper part of the bed the layers are thin and cherty. The sandstone overlying the coal seam on Birch creek has all the characteristics of a reliable building stone. It is a massive, mica- ceous sandstone, containing considerable ferruginous matter, with- stands atmospheric influences well, and forms a bold mural wall along the bluffs of the creek, from fifteen to twenty feet in height. It will furnish an abundant supply of building stone for this part of the county. On Bear creek, the sandstone is more unevenly bed- ded, and somewhat unevenly textured, some portions of it showing a disposition to crumble on exposure to the atmosphere. If quarried for building stone, where it presents this appearance, it should be selected with care ; and the soft portions of the rock should be re- jected. In a word, this county has an abundant supply of building stone, not only for the use of the inhabitants within its own borders, but also a large surplus for the supply of other portions of the State. The agricultural resources of this county are very similar to those of Jersey county ; and what we have said in relation to the soil and timber of that county would be equally applicable to this. The prairies are usually small ; and all the streams are skirted with belts of excellent timber. Away from the river bluffs, the lands are gen- erally level or gently rolling ; and the soil is very productive. Corn and wheat are the great staples of this portion of the State; and the cultivation of these great cereals, and stock-raising, are the prin- cipal pursuits of the farmer. Since the completion of the railroad through this county, its market facilities are greatly increased, and the value of its rich farming lands correspondingly enhanced, since its products are made accessible to the best markets of the country, at all seasons of the year. CHAPTER IY. SCOTT COUNTY. This county lies immediately north of Greene, which forms its southern boundary, and it is bounded on the west by the Illinois river, and on the north and east by Morgan county. It embraces a superficial area of about seven townships, or two hundred and fifty- two square miles. A broad belt of alluvial bottom lands, from three to four miles in width, skirt the shore of the Illinois river, and ex- tend 1 from north to south throughout the county. These bottoms are mostly prairie, with narrow belts of timber skirting, the streams. The middle portion of the county is generally rolling ; and some por- tions of it adjacent to the river bluffs are broken and hilly. The eastern portion is comparatively level, and is interspersed with small prairies. More than one-half of the entire surface of the county was originally covered with a heavy growth of timber, embracing the usual varieties already enumerated in the counties south of this. The ancient valley, now occupied by the Illinois river and its alluvial bottoms, was originally much wider through a considerable portion of the county than it is at the present time, and was exca- vated through solid limestone strata, to the depth of more than a hundred feet. This valley originally extended considerably farther east than the present line of river bluffs, through that part of the county lying south of the Mauvaisterre, down to within about a mile of the south line of the county ; and the limestone strata have been entirely removed by erosion, their place being now occupied by accu- mulations of loess and drift, which form the bluffs ; and it seems probable that the original valley was nearly or quite twice as wide at this point as the present one. The date of this erosion can not now be determined, farther than to state that it occurred anterior 60 ECONOMICAL GEOLOGY OF ILLINOIS. to the accumulation of the Quaternary formation, and subsequent to the deposit of the lower Carboniferous limestones. In the vicinity of Moore's coal bank, on Sandy creek, we see unmistakable evidence of an erosion that must have taken place at a period anterior to the deposit of the Coal Measures, and subsequent to the formation of the lower Carboniferous limestones, because we find that the St. Louis limestone and the upper beds of the Keokuk limestone have been removed by erosive forces, and that the over- lying Conglomerate of the Coal Measures is here made up in part of the fragments of the missing limestones, and rests unconformably on the Archimedes beds of the Keokuk series. It is perhaps impos- sible to determine at the present time whether or not these erosions of the limestone strata at the two localities cited are due to a single cause, and occurred simultaneously in time ; but it seems quite prob- able that they did not, otherwise the coal-bearing strata should be found filling in part the ancient river valley in the place of the Quaternary. It seems more probable that they belong to two dis- tinct and widely separated epochs, one of them dating back to the commencement of the Coal period, and the other occurring much later, but anterior to the accumulation of the Quaternary deposits, and simultaneous with the formation of the principal valleys in which our large rivers now run. From the point where the limestones disappear in the bluffs, about one mile above the south line of the county, to the Mauvaisterre creek, the Quaternary deposits are the only formation exposed in the vicinity of the bluffs, and these fill the eastern portion of this ancient valley, as before stated, to the depth of from one hundred to one hundred and twenty feet. Where these heavy accumulations of Quaternary beds occur, the surface is cut up into somewhat abrupt hills and ridges, as is seen in the vicinity of Glasgow, and especially west and northwest of that town. These lands, however, possess an excellent soil, and were originally heavily timbered with white oak, hickory, ash, elm, walnut, sugar maple, linden, wild cherry, etc. ; and, since they have been brought under cultivation, they prove to be among the most productive lands in the county. Wher- ever the land was originally covered with such a growth of timber as that just mentioned, there can be no question as to the superior quality and productive capacity of the soil; and these lands are really preferable, for most agricultural purposes, to the best prairie lands of the adjacent region. In the geological structure of this county we find but a slight variation from that presented by the adjoining county of Greene ; SCOTT COUNTY. 61 and a general section of the strata will be found to present only this difference, that the Kinderhook group will be wanting at the base, and a few feet in thickness of Coal Measures near the top, cutting off coal No. 5 and its associated strata. The following section will show the relative thickness and order of superposition of the strata in this county: Quaternary 100 to 120 feet Coal Measures Sandstone and shale 20 to 40 " Band of limestone 2 " Bituminous shale Coal No. 2? 2 to 3 " Sandstone and shale '. t 30 to 40 " Bituminous shale 1 to 4 " Coal (Exeter seam) No. 1 2& to 3 " Dark-blue clay shale 2 to 3 " , Compact, dark-blue limestone 3 to 4 " Light-gray clay shale, or potters' clay 10 to 12 " Shaly sandstone and conglomerate, with bands of iron ore, and locally a thin seam of coal 6 to 15 " Lower Carboniferous Limestone St. Louis limestone 20 to 40 " Keokuk limestone 75 to 100 " Burlington limestone 100 to 120 " The Quaternary deposits in this county present the same general features as those noticed in the report on the adjoining county of Greene, and it is therefore unnecessary to repeat them here. The loess caps the river bluffs, and often reaches a thickness of forty to sixty feet, forming bald, grassy knobs along their summits. Coal Measures. The strata belonging to the Coal Measures in this county have an aggregate thickness at their outcrop of about one hundred and thirty feet, and include the horizon of two or three coal seams, only one of which, however, promises to be of any con- siderable value here. The sandstone overlying the Exeter coal outcrops on all the streams in the eastern portion of the county, and the full thickness of the measures above this seam may be estimated at from eighty to ninety feet. This thickness includes a bed of bituminous shale, which probably represents the horizon of the Burrows coal, in Greene county, and perhaps also the Neelyville coal, in Morgan county. Those desirous of mining the Exeter coal, in the east part of the county, will have to sink a shaft through these sandstones, and also the overlying drift, which will comprise a variable thick- ness of from seventy-five to two hundred feet of strata. On a small branch east of Manchester we found the upper sandstone represented in the foregoing section well exposed, including the upper bituminous shale. The measures here consist of about thirty or forty 62 ECONOMICAL GEOLOGY OF ILLINOIS. feet of sandy shale, with a single stratum of hard, micaceous sand- stone, about a foot in thickness. There was also a partial exposure of a band of limestone, underlaid by bituminous shale. The Exeter coal has been opened at various points along the line of outcrop in this county. Tuft's coal mine is on the Big Sandy, two miles east of Winchester. The coal is here about three feet in thickness, with a good roof of bituminous shale, from three to four feet thick. It is underlaid by shaly clay, from .two to three feet thick, and also by the steel-gray, nodular limestone already men- tioned as underlying this seam on Birch creek, in Greene county. Below this limestone there is a bed of potters' clay, from ten to twelve feet in thickness. This clay closely resembles that on Wolf Eun, in Greene county, and probably holds the same stratigraphical position. Traces of a thin bed of sandstone were seen, along the banks of the Big Sandy, that seemed to underlie the potters' clay, and to rest on the St. Louis limestone. At Moore's coal mine, on the Little Sandy, formerly known as Frost's mine, the following beds are exposed in connection with the coal seam : Sandstone and sandy shale 8 feet Bituminous shale 3 Coal 2 to 3 Shaly clay 3 Nodular limestone 4 to 5 Clay shale, or potters' clay 10 to 12 Conglomerate, containing geodes, etc 6 to 10 Shale, with bands of iron ore 4 Keokuk limestone 10 to 15 In this section it will be observed that the St. Louis limestone, on which the Coal Measures usually rest in this county, is absent, and has no doubt been removed by erosion before the deposition of the Coal Measures. The Conglomerate, which forms the base of the Measures at this locality, is composed of sand, fragments of lime- stone from the St. Louis group, and geodes from the upper part of the Keokuk limestone, all intermingled together, and cemented with ferruginous matter. In some portions of the Conglomerate at this locality, the siliceous geodes peculiar to the Keokuk limestone are as thickly embedded as they are in the geode bed itself when most perfectly developed; and the bed appears to be formed, in good part, at least, from the debris of the St. Louis and Keokuk lime- stones. The Conglomerate, with about four feet of shale that may be said to form its base, rests directly upon thin-bedded limestone, containing Archimedes Owenana, Platyceras equilatera, Barycrinus stellatus, and Productus semireticulatus. One geode from the Conglom- SCOTT COUNTY. 63 erate at this locality was found to be entirely filled with sand, which had been converted into sandstone. Another was found with the cavity partly filled with brown oxide of iron, that had no doubt filtered into it after it was inclosed in the Conglomerate. The coal seam at this locality, which has been worked for many years, is reputed to be the best smith's coal in this part of the State. This reputation was acquired while in the possession of the former owner, Mr. Frost, who had the good sense to separate the coal from the upper part of the seam, which is quite free from iron pyrites, from that below, and to sell that exclusively for blacksmith's use. In this way he made a reputation for his coal that insured the sale of it to all the blacksmiths in this region, though the same seam had been opened at many other localities. The reputation of our Illinois coal has always suffered from the careless nanner in which it has been mined, the workmen putting into the "wagon," without scruple, along with the coal, the slate and sulphur balls that should always be carefully separated from the coal in mining, because it cannot readily be done afterward. About a mile southwest of Moore's place, a coal seam has been opened in the bed of the creek, where it has been worked by "strip- ping," or removing the overlying beds of soil and gravel. This coal rests directly on the Keokuk limestone, with only a foot or two of shaly sandstone between, and occupies the same horizon with the shale and iron ore bands in the section at Moore's. The nodular limestone under Moore's coal crops out in the hillside at this local- ity about fifteen feet above the level of the lower coal. The pit was partially filled with water, so that the thickness of the coal was not accu- rately measured ; but it is probably from two to two and a half feet. This is no doubt a purely local deposit, representing what is known at more southern localities as the Conglomerate coal. Thin layers of shaly sandstone, with Stigmaria, were seen in the debris of the creek, that appeared to have come from under the coal. This coal has not been met with at any other localities in the county. The Exeter seam, in the vicinity of that town, varies from two feet to two and a half in thickness, and is sometimes underlaid by the steel-gray nodular limestone, already noticed at other localities, as is the case at Neeley's place, a half mile northwest of Exeter; and at other points, as in the immediate vicinity of the town, there is only a shaly clay, from two to four feet in thickness, between the coal and the St. Louis limestone. The roof at Neely's mine is a hard bituminous slate, passing locally into a cannel coal. It 64 ECONOMICAL GEOLOGY OF ILLINOIS. contains great numbers of Discina nitida, and more rarely Lingula mytiloides and Productus longispinus. About twenty-five or thirty feet above the Exeter seam is the Neeleyville coal, which is extensively worked at Neeleyville, in Mor- gan county, near the north line of this county, but is rarely, if at all, developed in this or the counties immediately south of this, on the east side of the Illinois river. At Neeleyville, a shaft was sunk from the upper to the lower seam, showing the distance between them to be about thirty feet. The upper or Neeleyville coal is prob- ably the equivalent of coal No. 2 of the general section, and, in many portions of the State, is quite uniform in its development. Although the horizon of the Neeleyville seam has been found exposed at many localities in Scott and Greene counties, yet no bed <^f bituminous coal has been seen that could be identified with it, unless it is the equivalent of the Burrows coal in Greene county. The section of the Coal Measures in this county includes the hor- izon of three coals that are developed in some of the counties on the west side of the river, of sufficient thickness to be worked with profit; but we saw no evidence of the development of any but the lower seam here, though it is quite possible that one of the others may be found in the eastern part of the county, where there are now no natural exposures of the strata. St. Louis Limestone. This limestone is the fundamental rock on which the Coal Measures rest at every locality examined in this county, except that at Moore's coal mine, on Little Sandy. About one mile southeast of Winchester, it is well exposed on a small branch of the Big Sandy, where it is overlaid by the Conglomerate. The exposure at this locality affords the following section : Conglomerate sandstone 10 to 12 feet Gray limestone 3 to 4 " Thin-bedded greenish-gray sandstone 3 " Massive brown magnesian limestone, with some thinner beds of hydraulic limestone 27 " The Conglomerate at this locality appears to be only a local development, or an outlier form of the adjacent Coal Measures. The gray limestone that forms the upper bed of the St. Louis series, at this locality, has been quarried and burned for lime. The brown magnesian beds below are quite massive, some of the layers being two feet or more in thickness. They contain numerous fossils, among which are Rhynchonella mutata, Retzia Verneuliana, Productus Altonensis, Spirifer faieatus, and S. Keokuk, with several undeter- mined species of Bryozoa. On the Big Sandy, in the vicinity of Winchester, this formation is well exposed, and is a regularly SCOTT COUNTY. 65 bedded gray limestone that makes a durable building stone, and is also burned for lime. The upper portion of the bed is generally calcareous in this vicinity, while the lower part is generally arena- ceous and magnesian, and contains local intercalations of true sandstone. At Exeter, the limestone exposure is from twenty to twenty-five feet in thickness, and consists of alternations of gray, compact limestone, with beds of brown magnesian rock, which pass locally into an earthy, buff-colored, hydraulic limestone. A half mile west of Exeter, the magnesian beds contain geodiferous cavi- ties lined with crystals of dolomite. There are also some intercala- tions of green and brown shaly layers in the limestone at this locality. Along the bluffs of the river, from a point half a mile above where the Exeter and Naples road intersects them to the north line of the county, this limestone is exposed at short intervals. It is very variable in its lithological character, in this part of the county, and consists of alternations of sandstone and limestone, which seem to replace each other at short intervals. About half a mile above the road just mentioned, an exposure of only about six feet in thickness was to be seen, consisting of a regularly-bedded greenish-gray sandstone, some layers of which appeared to be some- what 1 calcareous, and contained casts of Rhynchonetta, and some other shells. It appeared to be a good building stone. A half mile above this, a massive gray and brown coarse-grained limestone was seen, from twelve to fifteen feet in thickness, and apparently occupy- ing the same horizon as the sandstone at the other locality. The rock has a concretionary structure, and presents no regular lines of bedding, but splits with considerable regularity in either direction, and makes a good building stone. It contains some fossils ; and we obtained at this locality Productus ovatus, P. tenuicostus,* Spirifer Keokuk, with two or three species of fish-teeth. It is overlaid by about eight feet of shaly limestone, without fossils. At Henry Smith's place, scarcely a half mile above the locality just described, extensive quarries have been opened for building stone. The rock is here mainly an even-bedded greenish-gray sandstone, with some thin layers of magnesian limestone, and is an excellent building stone. A half mile below Bluff City, a similar rock has been quar- ried for the construction of culverts on the railroad. At this point the sandstone contains many fragments of plants, and resembles, *This name was used by Prof. HALL, in the Iowa Report, to designate a form of Pro- ductus that is probably only a variety of P. semireticulatus. If it proves to be a distinct species, the name should be tenuicostatus. 5 66 ECONOMICAL GEOLOGY OF ILLINOIS. and might be easily mistaken for, a Coal Measure sandstone. About a mile east of Bluff City, near Vangundy's, we find regular beds of gray limestone, belonging to the St. Louis series, outcropping in the bluffs of the creek, and presenting the usual characters of the calcareous beds of this formation. From what has been said of the various outcrops of this limestone in this county, it will be seen that it is exceedingly variable in its appearance and lithological characters; and if an observer was to meet with it for the first time in this county, he would most likely be somewhat puzzled by the, peculiar features that would be presented for his examination; for we here find the commencement of certain lithological changes in the character of this formation, which, on the eastern borders of the coal-field, extend into the lower groups, and merge nearly the whole of the lower Carboniferous limestone series into green shales and shaly sandstone. Keokuk Limestone. The only exposure of any considerable portion of this limestone met with in this county was on the Little Sandy, where it directly underlies the Coal Measures. The rock at this exposure is quite thin-bedded and cherty; and not more than ten or fifteen feet in thickness was to be seen here. At the river bluff, on the Exeter and Naples road, there is an exposure of about thirty- five feet of calcareo-argillaceous shales, with geodes, which no doubt represent the upper part of this formation. About the middle of the bed, at this locality, there is a band of hard brown magnesian limestone, about two feet thick, which contains Hemipronites creni- stria, Spirifer Keokuk, Productus punctatus, etc. These beds undoubt- edly belong above those that outcrop on the Little Sandy. The lower part of this limestone we did not find exposed at any of the localities examined in this county. Burlington Limestone. A half mile above the south line of the county, on William T. Collin's place, there are about one hundred and twenty feet of this limestone exposed in the river bluffs; and. it is overlaid by from fifty to sixty feet of loess. The limestone here presents its usual characters of alternating beds of light-gray and brown limestone, with some cherty material in seams and nodules. This limestone appears along the bluffs for about a mile above the Greene county line, when it disappears ; and the mural bluffs, which it forms wherever it is found, give place to rounded hills of loess and drift. About half a mile south of Glasgow, this lime- stone is again seen on a small branch of the Big Sandy, in an exposure about fifty feet in thickness, where it presents the same general characters as at the locality first noticed. The upper part SCOTT COUNTY. 67 ( of the mass is quite cherty here, and is comparatively worthless for economical purposes ; but the lower part affords massive beds of gray and brown limestone of good quality. Fossils were more abundant at this locality than in the river bluffs ; and we found the following species : Spirifer Grimesi, S. plenum, Orthis Michilini, Atkyris lamellosa, Actinocrinus Christyi, A. Verneuilianus, A. Mis- souriensis, A. multiradiatus, and undetermined species of Chateocrinus and Agaricocrinus. Economical Geology. Coal. More than one-half of the entire surface of the county is underlaid by the Coal Measures ; and, although these measures only include the horizon of three seams of coal, only one of which appears to be developed over any considerable extent of surface, yet the Exeter seam alone, which is the most reliable one in this county, will furnish an ample supply for all local demands. From its posi- tion at the very base of the measures, it must necessarily underlie the whole extent of surface which the Coal Measures cover, and no natural exposure of the proper horizon for this coal was seen, but the coal itself was present. The seam varies in thickness from two to three feet, and has a good slate roof that admits of the removal of all the coal, and requires only a moderate expense for cribbing; and the coal it affords is better than an average of the Illinois coals in quality. In the summer of 1853, while engaged in making a preliminary examination of the counties adjacent to the Illinois river, I found that "Frost's coal" had a wide-spread reputation throughout the adjoining counties on both sides of the river as the best smith's coal in this portion of the State; and I fully expected, on reaching the locality of this coal, to find that it was furnished by a different seam from any that was worked in the adjacent region. Bat, on reaching Frost's mine, I was somewhat surprised to fine that his celebrated smith's coal was obtained from the same seam that I had been tracing through the adjoining counties, and that its enviable reputation was solely due to the judicious manner in which the mine was worked. The top coal, which was quite free from sulphuret of iron, was separated from the inferior portion in mining; and the different qualities of coal were sold at different prices and for the special uses to which they were best adapted. If the coal miners and dealers generally in this State would adopt a similar system, it would tend to greatly improve the reputation 68 ECONOMICAL GEOLOGY OF ILLINOIS. of the Illinois coals wherever they are used. Three analyses were made by Mr. PKATTEN, of coal from this seam in Scott county, with the following result : BAKKEB'S COAL. Specific gravity 1.2396 Loss in coking .- 42.8 Total weight of coke... 57.2 100.00 Moisture 5.5 Volatile matters 37.3