Jersey County, Illinois - Chapter 2: Geological History, 1919

Natural Records

-Jersey County lies on the western border of the state, at the junction of the Illinois River and the Mississippi, and includes an area of about ten townships, or 360 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, the Mississippi and the Illi¬ nois rivers. The central and eastern portions are mostly prairie, and are comparatively level or gently rolling ; while the southern and western portions become more broken as we approach the river bluffs, which are intersected by deep ravines, separated by narrow ridges, many of which are 100 to 200 feet in height. This portion of the county was at one time heavily timbered. The county is well watered by Macoupin Creek and its tributaries on the northern portions, and by Otter Creek and the Piasa and their affluents in the southern and western portions of the county.

Geological Structure

tion of any county in the state. The outcrops of stratified rocks include a thickness of over 1,000 feet of strata, ranging from the lower coal measures to the Trenton limestone of the Lower Silurian period. Some¬ time after the deposits of the carboniferous period were made, some great convulsion of the pent up forces of nature caused an upheaval of the strata, and a mountain or rather the half of a mountain, arose, whose highest point was in the southern portion of Calhoun County, with the foot of the elevation extending in a half circle from Alton through a portion of Madison, Jersey, Greene, and Calhoun counties, to the southwest corner of Pike County on the Mississippi River. This singular mountain doubtless presented on its southern and western side a mural wall, showing the whole range of the Paleozoic strata, from the St. Peter's sandstone of the Calciferous period to the coal measures, including over 100 feet of the latter formation. Jutting up against the base of this precipice, the rocks, with the coal measures on top, lie in their natural positions, though somewhat distorted, as they had been raised up and fallen back again. The lowest rock exposed in Jersey County is the Trenton limestone.

The Drift Period

This mountain was eroded away by the drift period, which, according to the theory of Agassiz, was an immense glacier, miles in thickness, and the finishing stroke in the earth's creation. The erosive forces of the drift period left the site of the mountain on a general level with the surrounding country. The stream known as Otter Creek, has its source over the coal measures, in the prairie near the city of Jerseyville, and its course in a western direction for a dozen miles to its mouth, passes directly over the exposed edges of the rocks raised by the up¬ heaval, thus presenting nearly the whole series of the rocks in the county. This locality, from the number of strata exposed in so limited an extent, makes it the most interesting field for the study of geology of which I have any knowledge. Recently, in one day, with a class of graduating students, we passed over all these rocks, recognizing the different members, and collecting fossils from each.

Geological Groups

given are some of them local, but are those by which they are designated in the geological report of the state of Illinois by Professor Worthen:

We shall now proceed to describe the strata represented in the fore¬ going section, taking them up in their order of sequence and giving some of the more prominent features that have attracted our attention.

In the Quarternary System we include the Alluvial, Loess and Drift, comprising all the loose, superficial material that overlies the stratified rocks. The alluvial deposits of this county are the bottom lands bordering on the Illinois River, and on the Piasa, Otter and Mc- Coupin creeks. The bottom along the Illinois River is a deep, sandy loam, differing somewhat in localities, by being formed wholly from the sediment deposited from the annual overflow of the river, or mainly formed from the wash from the highlands of the adjacent bluffs. These bottom lands are exceedingly fertile, producing annually large crops of grain and vegetables, which are grown year after year on the same ground, with but little perceptible diminution in the value of the crops. These lowlands are gradually being elevated from year to year by causes already referred to ; the swampy portions are filling up or being drained, and the arable area constantly increasing. The allu¬ vial lands of Jersey County, will, at no distant day, be very valuable.

Delta Aylward John R. Aylward

narrow ridges. These bluffs are covered with a heavy deposit of Loess, varying from twenty to sixty feet in thickness. The term Loess is applied by geologists to certain deposits of partially stratified marly sands and clays, mainly restricted to the vicinity of our great river valleys. The deposit is in a finely comminuted condition, and contains the remains of fresh water and land shells as well as of some of the bones of the animals of that period. It was doubtless formed after the deposition of the true drift, and when the Mississippi River more nearly resembled a lake than a flowing river. Where the deposit of Loess is well developed, the bluffs usually present a series of bald knobs, which form such a marked feature in the topography of our county along the rivers.

This formation, from its peculiar nature, is easily manipulated by the farmer, and yields excellent crops. The Loess seems more especially adapted to fruits and vines, and some of the finest orchards and vine¬ yards in the county are on this formation. It does not extend far back from the river, except in the valleys of the creeks and streams, which are filled with the deposit in some instances three to six miles from the bluffs, an evidence that the valleys were excavated by other agencies than the water which now flows in them. In many places in the deposits of Loess in the county are found curious concretions, which go by various names, such as "petrified potatoes," "walnuts," etc. Some of these are very singular, but none of them are fossils, being simply secretions, and their presence is without doubt due to some chemical action among the materials of which the Loess is composed.

Drift

The Drift deposits are those accumulations of clay, sand and gravel which overlie the stratified rocks. The upper part of this deposit in this county is a yellowish, brown clay, furnishing an inexhaustible supply of material for the manufacture of brick. It is also used in the manu¬ facture of coarse pottery, by being mixed with the blue clays beneath it. The middle division of the Drift is usually a gravel bed, with clay or sand intermingled, and is the main supply of water for our wells. Boulders of granite, sienite, greenstone, quartz and porphyry are often washed out of these gravel beds, and are seen in all the courses of all of our streams. They are sometimes called "lost rocks," which name is quite suggestive, as they are indeed far away from their original ledges. The sand in the stream is all washed out of the Drift.

The base of the Drift in this county is a blue, plastic clay, in which are often found fragments of the vegetation of the period. A large proportion of the materials occupying the Drift deposits have been de¬ rived from regions far beyond the limits of the state, and consist of water-worn fragments of primitive rocks from the Lake Superior region and beyond, and which have been transported southward by the com¬ bined action of ice and water, and were distributed over the valley of the Mississippi as far south as the Ohio River, where the whole valley was covered by a vast sea of water.

Sometimes fragments of valuable materials, such as gold, silver, copper and lead are found in the Drift, and have been the cause of leading many persons to give fruitless search for mines supposed to be hidden beneath. All over the county, in digging wells, pieces of coal are found that have been dragged away from the coal measures, and deceive the unwary by their presence. Occasionally, in digging wells, after penetrating the Drift deposits, an old soil is discovered. This is generally found in ancient valleys that existed previous to the Drift period. Otter Creek cuts through one of these old valleys not far above the "Iron Bridge," and there is plainly to be seen, below the base of the Drift, a curious black or dark-brown formation, almost wholly com¬ posed of the limbs, leaves and fruits mingled with a true soil. From a cubic foot of this old deposit we extracted perhaps a score of perfect cones, from an inch to three inches in length, that belonged to some old conifer tree. Of the vegetation of this period, but little is known; the same may be said of the animals. They were, without doubt, fitted to live in a cold climate. We have some remains of an animal found in the Drift deposits near Grafton. It was an animal as large as an ox, and had long tusks, very different, however, from those of an ele¬ phant. It is unknown to science. From the same locality we have the teeth of a mammoth species of an elk or reindeer, together with the remains of rodents of unknown species. We have also a tooth of some strange herbiverous animal, found in digging a well near the village of Elsah, a few miles below Grafton. On the Piasa, Macoupin and Otter creeks a number of the remains of the huge and peculiar mammals of the Drift period have been found. Relics or remains of this kind, found in digging wells or other excavations, should be carefully pre¬ served. They are fragmentary pages of lost history. As the Drift period did not leave its deposits over the entire continent, there were doubtless places where many of these animals, as well as their con¬ temporary man, survived to make new history.

Tertiary Period

Although no beds of the Tertiary age have been identified in this county, certain indications have been observed that would go to show this formation exists, in local patches at least, in the valley of the Illinois River. While digging a well on the William's farm on the bottom, four miles from the mouth of the Illinois River, at a depth of twenty feet, a stratum of marl and sand was discovered, in which were fossils undoubtedly of the Tertiary age. One of these fossils, in our possession, is a well preserved shark's tooth, some four inches long. The river valley at this point is three or four miles wide, and seems to be filled with the true Drift deposits, beneath which was found the shark's tooth. Further research in this locality will no doubt reveal matter of great interest to science.

Coal Measures

The rocks that belong to the coal measures in this county have a thickness of about 200 feet, embracing three or more seams of coal of workable thickness. These coal beds underlie the eastern portion of the county. There is no coal of any value west of the Jacksonville and Alton Railroad, which runs through the county from north to south. On the western side of this coal region the measures, if any are found, are thin and of no great value, but as we proceed easterly the measures increase in thickness, and the seams of coal become more numerous. The following section is compiled from various local exposures, examined by the state geologist as well as myself, and given in his report, from which we draw largely in writing this paper. The section may be taken as the approximate thickness of the coal measures in this county:

The upper beds of this section, including the two upper coal seams, can be seen in one locality hear the town of Brighton. The coal beds in the state of Illinois are numbered from one to twelve, commencing with the lower seam which is known as No. 1. In the rocks, in immediate connection with each one of these coal seams, are certain fossils that are peculiar to them, generally in the shale, limestone or sandstone that form the roof over the coal. By these fossils, with which anyone can with a little study become familiar, the position and proper horizon of each coal vein is ascertained.

Brighton Coal Veins

The two coal veins near Brighton, on the eastern side of the county, are known by the associating fossils as Nos. 5 and 6 in the series of veins in the great coal fields in the state. These are the best workable beds in the state, being the greatest in thickness, and furnishing the most valuable coal.

These two beds both crop out along the eastern portion of the county, and are separated by twenty to thirty feet of shales. They are both underlaid by a calcareous clay shale, passing into limestone. The lower bed is overlaid by a brown limestone, which sometimes forms the roof immediately over the coal, or is separated from it by a thin bed of bituminous shale. The coal bed No. 5 furnishes most of the coal mined in the county, as it does in the state. It no doubt underlies the greater part of townships 7 and 8, in range 10, and may be found still further west, but so near its outcropping edges its presence is uncertain.

Coal Seam Near Delhi

Coal beds Nos. 2, 3 and 4 of the series seem to be wanting in Jersey County : at least we have failed to find any evidence of their presence.

James Aylward

There is. however, a third coal seam exposed on the Piasa Creek, near Delhi. This coal seam has been opened at various localities along the banks of the creek, and varies in thickness from two to three feet, and is overlaid by a few inches of bituminous shale, which passes upward into a brown clay shale. It is underlaid by from four to five feet of fire clay and about ten feet of sandy shale and sandstone, which lies directly upon the St. Louis limestone. There is no coal seam below this one, and it is probably the lowest one in the series, and equivalent to No. 1. It is not so good a coal as Nos. 5 and 6.

In sinking a well for a mill in the city of Jersey ville, a few feet of micaceous sandstone was passed through which in all probability belongs to the coal measures. The rocks exposed in the streams north of Jerseyville belong below the coal measures. The irregular borders of the forma¬ tion, without doubt, run in a northeast direction from the city. There is plenty of coal in Jersey County for the future use of the inhabitants. Its easy access, on account of being near the surface, and consequent .small outlay for sinking shafts, should make it very cheap to the con¬ sumer. Better roads will bring it nearer to the markets.

Chester Limestone

Passing below the coal measures we come directly upon the lower or subcarboniferous rocks. In several places about the head branches of Otter Creek are exposed thin outlines of the Chester group. It is not perhaps more than fifteen feet thick. On a branch of Otter Creek, near Beaty 's Mound, there is a stratum of white sandstone, three or four feet thick; below this several feet of thin-bedded sandstone is seen, which rests on the St. Louis limestone. The sandstone, which, however, is really a siliceous limestone, contains many beautiful fossils, among which are Retzia vera and Athyrus ambigua, familiar forms in the Chester group. At Cooper's quarries, three miles southwest of Jersey - ville, the same beds are partly changed into a brown, ferruginous, shaly sandstone, in which are curious nodules of good iron ore. In this forma¬ tion we found several beautiful pentremites, with a triangular base, and of an undetermined species.

St. Louis Limestone

velopment through the central portion of the county, and its maximum thickness reaches from 100 to 150 feet. This rock, from its central position, is more generally used than any other rock in the county for building purposes. It has the greatest development on the Piasa, and thins out in the northern part of the county until it is not more than about thirty feet thick north of Jerseyville. There are many good quarries on the Piasa, and the abutments of the railroad bridge across that stream are built of this rock from quarries in the vicinity. There are excellent quarries both south and west of Beaty's Mound on Otter Creek, and about three miles southwest of Jerseyville.

It is the underlying rock beneath the city of Jerseyville, and is sometimes reached in digging deep wells in that locality. Magnificent quarries of this rock are worked in the cities of Alton and St. Louis. In both places it is the same rock that is used in the manufacture of lime.

In the lower part of this formation in Jersey County there is a bluish, dove-colored hydraulic limestone, which is so soft in some places as to have the appearance of a bed of blue clay. It outcrops on the Piasa near its mouth, where there is a manufactory for making cement. It is simply burned in a kiln to deprive the stone of water, and then ground into flour. It makes an excellent article of cement, which, mixed by water with two-tliirds its bulk of clean sand, will soon harden into a body having almost the consistency and firmness of rock.

The bed worked at the hydraulic mills on the Piasa, is eight feet in thickness. Overlying the hydraulic limestone is a brownish mag¬ nesian limestone, in which are found Ortkis dukia, Spirifer lateralis, and a beautiful little pentremite peculiar to the formation.

This hydraulic limestone seems to be present wherever the St. Louis limestone is found in the county. Beds of it are exposed near Beaty's Mound, and it underlies the city of Jerseyville, where we have seen it brought up from the bottom of wells that were less than 100 feet in depth. The western limits of the St. Louis group of rocks in Jersey County, could form an irregular line from the Mississippi about mid¬ way between the mouth of the Piasa and the town of Elsah, north, one mile west of Beaty's Mound, thence to the Macoupin Creek. Five miles above Grafton, the St. Louis limestone is found, forming a part of the river bluff. It is not, however, in its original position, but seems to have been thrown down by the dislocation of the original strata caused by the upheaval of the Cap Au Grey axis, which crosses the Illinois River a short distance above. These rocks at Dinsmore's lime kiln resemble the upper beds at Alton, and make excellent lime. This group of rock will at some future day be a great source of revenue to the people of the county. The wealth treasured up in these quarries does not at present seem to be realized. A deposit of hydraulic limestone is a great treasure to any county.

Mines of both iron and lead are worked in the St. Louis group in Hardin County, in the southeastern part of the state, but in this county we have seen no indications of any mineral of value.

Keokuk Limestone

It is generally thin-bedded, seldom affording strata more than a foot in thickness. Almost the entire thickness of these rocks can be seen in the Mississippi bluffs above the mouth of the Piasa Creek. Fine ex¬ posures are also to be seen on Otter Creek and its affluents, between Jerseyville and Grafton. The rocks on Otter Creek at the iron bridge, for half a mile above and a mile below, belong to this group ; it is also exposed on the Macoupin, northwest of Jerseyville. The rocks of this group are not near so valuable as the St. Louis limestone, being shalv, thin-bedded, easily broken, and liable to crumble on exposure. It wTas formerly used to some extent in walling cellars and wells, for which purpose, as well as for small foundation walls, it answers very well.

One peculiarity of this group of rocks, is its beds of geodes, which occur in the shaly limestone strata, sometimes so thickly dispersed as to press against each other. These geodes or siliceous globes or spheres, are from half an inch to a foot and a half in diameter. Many of them are hollow spheres of quartz,, calcite, dolomite, gypsum, aragonite, pyrites, pearl spar, silicate of alumina, and many other minerals in a crystaline form. It is said that there is no formation in the state that presents such attractive and interesting specimens of crystalized minerals as are to be found in the geode beds of the Keokuk limestone. On some of the branches of Otter Creek after a severe rain storm, hundreds of these geodes can be seen lying loose in the bed of the stream. The Keokuk group of rocks is noted for its fossils and the beds of this formation in this county are rich with the remains of ancient life. Fossil shells, corals, encrinites and bryozoans of many beautiful and varied forms are abundant. Among the fossil shells, the most abundant are Spirifer Keokuk, Spirifer cuspidal: us, Productus punctatus and Platy- ceras equilatera. Of the corals, the most abundant are Z aphreniis Dalii, Splienopotera. Of the bryozoans, the curious screw-shaped Archimedes Oivenana is the most common. A familiar acquaintance with the specific character of the above named fossils, will enable anyone to identify the Keokuk rocks wherever they may be observed. Forty-eight species of fossil fishes have been determined from this group, and are figured in the state reports.

In some other part of the state this rock forms a good building stone. The "Mormon Temple," built at Nauvoo, at one time the most imposing building in the state, was entirely constructed of this stone.

Burlington Limestone

This group of rocks lies below the Keokuk limestone, from which it is separated in this county by cherty layers of considerable thickness, and which form beds of passage from one limestone formation to an¬ other. On a farm in Otter Creek, a good section of this chert bed, some twenty feet in thickness, can be seen with the overlying Keokuk beds, and between in the ravines and river bluffs north and west of Fieldon.

Among the numerous fossils, those characteristic and generally seen are Euomphalus latus, Spirifer Grimesi, Orthis Michelini, with Actinocrinus turbanatus and many beautiful and singular crinoids.

The Burlington rocks forming the bluffs on the Mississippi River in this county, form perpendicular cliffs nearly 200 feet high. These being capped by forty to fifty feet of Loess, make the entire elevation from 225 to 250 feet high. From the river they present a picturesque and beautiful appearance, the whole formation being weathered and worn into straight columns and buttresses that at a distance have the appear¬ ance of being the ruins of some old feudal castle, with towers and bastions, and buttressed walls; indeed the early French voyageurs who first ex¬ plored the Mississippi, on first catching sight of the picturesque bluffs at a distance, mistook them for ruins of great habitations made by human hands. Father Marquette in his diary speaks enthusiastically of their picturesque beauty, when first beheld by white men.

Kinderhook Limestone

This formation forms the basis of the Lower Carboniferous lime¬ stone series in this county, and rests directly on shales belonging to the Devonian epoch. Between Elsah and Grafton where this group is exposed in the bluff, it seems to be about 100 feet iu thickness. It con¬ sists of thin-bedded ash-colored, impure earthy limestone, with an occa¬ sional heavy layer of dolomitic limestone. At Grafton, in the hollow up which the road runs to the north, the formation is represented by fifty feet or more of gray, impure limestone, sometimes magnesian, with marly partings between the beds. These beds contain nodules of crystalizecl carbonate of lime, with a siliceous crust, resembling geodes in appearance, but containing no cavity within. At Grafton, in the Kinderhook, which overlies the upper quarries, there is a heavy-bedded, bluish compact limestone, called by Professor Swallow, in Missouri, litho¬ graphic limestone, from the general resemblance to the celebrated German stone used in lithography. The Missouri lithographic limestone in all probability occupies the same horizon as those compact beds of the Kinderhook in this county. This rock breaks with a smooth, conoiclal fracture, and from its compactness and fine texture no doubt would receive a high polish. Fossils are found in this group, but not in such abundance as in the Keokuk and Burlington. Some beds of the Kinder¬ hook furnish good building stone, and no doubt some of the strata would make good lime.

Black Slate

The Devonian system is not very extensively developed in this county, the whole extent not exceeding forty or fifty feet. It is divided into two groups, the first of which is known by the name of Black slate.

This group comprises a series of dark-blue, green, or chocolate colored shales, which pass locally into a black bituminous shale, from which it derives its name, which was given it by the early investigators of western geology.

In the deep hollow, going north from Grafton, this formation can be seen on the eastern slope, of a deep-blue color, and somewhat re¬ sembles the hydraulic limestone in the St. Louis, but is without its constituents, being a shale. In the same hollow the black slate changes its local color from blue to a greenish, brownish -hued shale. In Graham's Hollow, five miles northwest of Grafton, this formation is a black shale, highly bituminous. On Otter Creek, near the bluffs, in the lateral branches, are fine exposures of this formation. These black shales have a resemblance in color to coal, and at a distance had very much the appearance of an outcropping seam of bituminous coal. This has led many people to believe that coal existed in the vicinity, and much search has been made, and money and time expended uselessly. Almost every coal miner who has visited the localities where the black shale is ex¬ posed, has been decided in his opinion relative to the presence of coal in the vicinity. Coal miners generally have a very limited knowledge of geology.

This formation occupies the horizon of the great oil producing zone of Ohio and Pennsylvania, but the bituminous beds in this county are not thick enough to promise any considerable yield of oil. The ex¬ posures of this formation extend in this county only from Grafton to the mouth of Otter Creek, the lines of the outcropping groups becoming shorter and more narrow as we approach the center of the upheaval.

Hamilton Limestone

This group also belongs to the Devonian, and together with the Black slate comprises all the deposits of that system in the county. It may be proper to state here, that the scarcity of fossils from the Black slate makes it questionable whether it belongs to the Lower Carboniferous series, or to the Devonian. There seems to be a plain line between the Black slate and the Hamilton group ; indeed the line of demarcation is more clearly observable than between the black slate and the Kinderhook. There is found a Lingula in the Black slate that is identical with a Lin¬ gula found in the Devonian in other states, and its stratographical posi¬ tion would seem to place it in the Devonian.

The Hamilton limestone furnishes many fossils characteristic of the Devonian system. A thin strata of the group exposed in Graham's Hollow, a few miles northwest of Grafton, is literally made of the fossil inhabitants of that old Devonian sea. Some of these fossils are very per¬ fect. Slabs of this fossil iferous strata make beautiful cabinet specimens. In some of the deep ravines, near the mouth of Otter Creek, many of these fossils are weathered out, and can be picked up from among the debris.

In this locality corals are seen in remarkable profusion, being at one time possibly a coral reef in the shallow Devonian ocean. The fossils most characteristic of the Devonian rocks of Jersey and Calhoun counties is a coral of the genus Heliopliyllum, of which there is one or more unde¬ scribed species. These Heliophyllum are called by some of the local collectors, "petrified cows," and in fact they greatly resemble a short, thick, curved cow's horn.

The Hamilton group is exposed in a narrow belt in the ravines and creeks between Grafton and the mouth of Otter Creek. It is not more than ten to fifteen feet in thickness in the county.

In Graham's Hollow, a few miles from Grafton, this formation is saturated with petroleum. Upon taking a portion of the rock, freshly broken from the bed, it has the smell of coal oil, and the petroleum can he seen filling the cavities in the rock. At two or three points in this locality borings have been made through the Black slate, Hamilton lime¬ stone, and some distance into the Niagara rocks below, in search of coal oil, but no paying quantities were discovered. These rocks are, however, in the same horizon as the petroleum districts of Ohio and Pennsylvania. The unmistakable presence of petroleum in the upheaval and outcrop¬ ping edges of this system, in its limited exposure in this county, is sig¬ nificant at least. All the rocks of the county have a strong inclination downward towards the northeast, on account of the upheaval mentioned at the beginning of this paper. If these rocks were tapped by boring on the east side of the county, where the rocks lie conformable and in a horizontal position, who knows but that coal oil may be found in quan¬ tities ?

Niagara Limestone

Underlying the Devonian system of rocks in Jersey County is the Niagara group of the Upper Silurian system. This group of rocks is important, from the great value of its material as a building stone. This formation is well exposed in the deep hollows and ravines, from the mouth of Otter Creek to the town of Grafton, where it forms the prin¬ cipal part of the bluff on the Mississippi. A mile below Grafton it disappears beneath the bed of the river, and we believe is seen no more in northern Illinois. It has thickness in this county of about 120 or 125 feet, and is a buff-colored dolomitic limestone, in regular beds, which vary in thickness from four inches to three feet. At Grafton the group is very even bedded, and dimension rock, almost any required size, can be easily obtained from the quarries, which are situated directly on the bank of the Mississippi River, with the very best shipping facilities. The rock lias a firm, even texture, cuts easily when freshly quarried, and can be readily worked into forms for ornamental purposes. It hardens on exposure, and is remarkably free from chert or deleterious material.

Beautiful fossils are found in the quarries at Grafton, the most abundant of which is a trilobite, C alymanbaclm, and a large multivalve shell, Orchoceras annulatum. There are six or seven species of these curious crustaceans, known as trilobites, some of them very large. There are also several species of orthoceras, with bivalve shells, crinoids, and corals. These fossils, especially the trilobites, are found in great per¬ fection, apparently in the exact positions as when living; in some in¬ stances a mark is left behind them, apparently the track of their travels, the whole indicating sudden death.

The crevices and apertures, caused by the shrinkage in the strata in this formation, often contain the most beautiful stalactites, or a beau¬ tiful encrustation of stalagmite on the floors and sides of the caverns. Fine crystals of calcite are frequently met with. This formation con¬ tains the most valuable building stone to be found in the state, and from the fact of the quarries being situated near the river, with the best of shipping facilities, ought to and will be a source of wealth to their owners some day. Some of the finest buildings erected at St. Louis had their walls made from stone taken from the Grafton quarries; not¬ ably among those buildings were the Lindell and Southern hotels.

Cincinnati Limestone

This group of the Lower Silurian system is represented in this county by forty or fifty feet of argillaceous shales. It appears to be mainly a soft, bluish, clay shale, that wTeathers on exposure about where it outcrops, to a pure clay, that apparently might be suitable for a potter's clay. This clay has somewiiat the appearance of some of the fire clays of the coal measures, but has not the same consistency. This clay is filled with innumerable, small lancet-shaped crystals of gypsum, or phosphate of lime. Many of these crystals are double ; some are half an inch in length, perfectly transparent, and exactly resemble the point of a physician's lance. Many of the crystals are found adhering to- gether, forming variously complicated groups. Great numbers of these crystals are seen wherever we have seen these clay shales weathering out in the county. No analysis of these crystals or the clay has ever been made, to our knowledge. They may prove to be of commercial value.

Owing to the soft argillaceous nature of these shales, good exposures are not often seen, they being generally covered up with debris from the bluffs or soil.

The outcrop extends from Mason's Landing, or Upper Grafton, wdiere the blue clay is exposed at the base of the old quarry back of the mill, to within a short distance of Coon Creek. In Graham's Hollow and the adjoining ravines, at the base of the bluff at Wheeler's Ferry, are good exposures of this formation.

Although this formation furnishes characteristic fossils in adjoin¬ ing counties, we have found but few in Jersey, enough, however, to know it occupies the same horizon.

Trenton Limestone

This group of the Lower Silurian rocks has a limited outcrop in the county. It is well exposed on the farm of S. P. Dinsmore, and extends in a northeast direction less than a mile, and is mostly confined to section 9, township 6, range 13. Forty to fifty feet of this formation is to be seen in this locality.

The rock is thin-bedded, compact, and of a light gray or white color, splitting easily, with uneven cleavage. It has been quarried and burned for lime, of which it makes a good quality, but not equal to that made from the St. Louis limestone. It is filled with the peculiar and char¬ acteristic fossils of the Lower Silurian age. Among those most familiar are OrtJiis iestudinaria, Spirifer lynx, Strophomena alternata, S. deltoidea, two or three species of Pleuromaria, Orthocertites, and a large species of Beceptaculites, or "sunflower coral," with remains of trilobites and crinoidea.

A good collector, might in a few hours, gather quite a collection of the fossil remains of the inhabitants of that ancient world represented in the old Lower Silurian seas.

The Trenton limestone is the oldest formation of which the little county of Jersey can boast. We have traveled over the edges of the upheaved strata from the coal measures to the Lower Silurian. The halfcircling limits of these exposures were growing more narrow as we

A collection, comprising a good specimen of all the rocks in the county with their accompanying fossil remains, would be of great in¬ terest to whoever should behold it. The little county has hidden away beneath her fertile soil an undeveloped wealth that but few realize. These natural resources are unequaled by any in the state or in the west, on account of their easy accessibility and nearness to market, as well as their great variety and adaptability for different purposes.

East of the Jerseyville and Alton Railroad, the county contains a valuable deposit of coal, as well as tire clay. Through the middle of the county is a belt of most excellent building stone, which also makes superior lime. In this same formation is a valuable deposit of hydraulic limestone, from which excellent cement could be made. In the western part of the county are immense quantities of lime rock, easily accessible for any purpose for which such material is used. All along that portion of the county bordering on the Mississippi and Illinois rivers, the waters of these great highway^ cast their waves against stratified limestone that ought in coming time to furnish no small share of the material to build up the future cities of the Mississippi valley.

Divine Purpose

The Creator, who made all things, made the earth for an abiding place for the chief of all his works - intelligent man. And in the earth's creation the Allwise Providence took good care to place, by the strangest means, earth's resources where they might be accessible and applied to the needs of mankind. This creation was not finished without the upheavals, such as appear in Jersey County and elsewhere; yet these upheavals would have been left mountains but for the erosive forces of the Drift period, which shoved off the unsightly elevations, and left the edges of the tilted strata accessible for man's uses. To the nat¬ uralist these strata of rocks, and coal and clay, are rock-bound volumes of ancient history.

From the Silurian to the coal measures in the county, each formation contains the inhabitants of its day, embalmed by a process of nature that will preserve them for all time to come. Earth's Creator, as though with a jealous care, has taken special means to preserve even the lowest of the first creation of earth's inhabitants. They are turned to solid stone, and so the record and history has been kept until the time when man, in his intelligence, should make records of his own that all man¬ kind might read.