The dividing line between the Coal Measures and the Upper Carboniferous is not clearly defined or easily fixed. Fossils pass across the line, and the strata are similar and entirely conformable. Plants and coal are the best evidences, and even these are not very strongly marked.
The area embraced by the Coal Measures is about nine thousand (9,000) square miles. Of the seventeen counties lying wholly or in part within its limits, all are in some degree supplied with coal. Under the head of coal, its extent, character and value will be described. How much of this area is underlaid by this useful article, we are unable at present to decide. This is, in part, owing to the fact, that the State has not been disposed to employ a geologist to examine the territory covered by the Coal Measures, as well as to the fact that the deposits near the coal beds are quite irregular.
The material of the deposits of the Coal Measures are very similar to those of the Upper Carboniferous, but more varying. The shales, particularly the blue clay shales, popularly called soapstone, are sometimes locally very thick. Several borings in Miami county, a thousand feet deep, passed through such shales, nearly the whole distance. They are so soft as to require tubing in the artesian wells. The sandstones are firmer and of more uniform grain than those of the later formations, in a few localities making good grindstones. Good flagging stone, as at Osage county, is produced by some of the thin layers of sandstone. The limestone at Fort Scott, Lane, Franklin county, and several other places, is of the compactness of marble, and is used for monuments.
The limestones are very persistent over large areas, but all other strata are quite variable. This is seen in the borings at various points in search for coal and oil. Trials within a few miles of each other, have struck entirely different deposits of shale or coal. Thus, at Pleasanton, Linn county, coal was found in one lead shaft of a workable thickness, and less than eighty feet from the surface, while in another shaft, two hundred and sixty feet deep, and only two hundred yards distant, none was found. Yet the surface strata are nearly horizontal. Near Wyandotte, in a boring five hundred and seventy feet deep, no coal was found, while, at Rosedale, less than four miles distant, two good seams of coal, over three feet in thickness, are reported, within three hundred feet of the surface.
Similar instances occur at other places. Other indications show local disturbances. The "horse-backs" in some of the coal mines in this part of the State are some of the evidences, yet no igneous traces, sufficient to produce even partial metamorphism, have been seen in this or any other part of Kansas. Nor has any dislocation of a strata, called a "fault," been seen. When the Upper Carboniferous series, outside and along the borders of the Coal Measures, have been penetrated by boring, and the latter entered, the underlying deposits have presented the same appearance of variation in the geological condition.
Such variance has been very strongly shown in the borings made in the lowest portions of this group, in Crawford and Cherokee counties. The facts are not yet all known, but point to two causes of the irregularities in the different deposits. The first is the varying conditions of land and water during the period of the deposition of the various materials; the other is the disturbances which are seen in the lead region of the adjoining counties of Missouri, which brought up the lead and zinc.
As an instance showing the first cause, let me cite this fact: There are at least thirty different strata in the Coal Measures in which are remains of land plants in shale or coal, and between each are strata containing well preserved remains of shells, corals and other oceanic animals. This shows conclusively, that this part of Kansas, was under the ocean and again raised to dry land at least thirty times during the period of the Coal Measures. Other indications lead me to believe that this oscillation, under and above the sea, took place more than twice that number of times.
Such things make it exceedingly difficult to form an estimate of the proportion of the Coal Measures which have underlying coal beds of sufficient thickness to pay for mining. Borings, in various townships where coal might reasonably be expected to exist, have found none. This reduces the area of the productive portion of the coal deposits. The Coal Measures which we have usually reckoned as productive, cover the surface over nine thousand square miles of our State, but not more than one-half, possibly not more than one-third of that number of miles, will afford us profitable veins of marketable coal. A careful examination of this area is earnestly required by the best interests of the State, in showing just where our mines of this article, consumed by all ranks of society, can be found.
Some remains of marine vegetation are found, but usually in poor preservation. Land plants are not abundant except in or near the coal beds. So far, a few new species have been added to science. Ferns are the most common, of the usual type of those found in other States, in Carboniferous deposits.
In Franklin county, two or three miles south of Ottawa, a sand-rock contains some finely-preserved fern and calamites. In the bed of the Neosho river, one mile southeast of Chetopa, near the old ford, is a deposition of stigmaria, (S. pucoides) or the underground branches of sigillaria. Many specimens were four inches in diameter, and we found one which was twelve feet in length. Some had the frond-like appendages well preserved. In Douglas county, near Baldwin, is an excellent locality of calamites (C. cannaeformis), which gives numerous specimens in excellent preservation.
We might name many other localities where good vegetable remains can be obtained in moderate quantities.
It is hardly necessary to state that the fossils of the limestone are exclusively marine. They are abundant, sometimes well preserved, but most frequently in fragments. Crinoid stems, usually in button-like sections, are seen almost everywhere, but a perfect crinoid has never been collected in Kansas. A few imperfect "heads" have been found. A few trilobites are seen, seldom whole.
Fish are represented by a few species and a small number of specimens, all of new species. A few years ago, some fragments of shale containing teeth of fish, were taken from the roofing of the coal seam at Osage City. The best portion contained the teeth from nearly half the lower jaw, in their natural position, numbering over four hundred. Some time after, nearly the whole jaw was secured. The number of teeth in the whole jaw was nearly twenty-five hundred. It was a cestraciont selachian, a variety of the shark family. It is well known that the shark tribe has no solid bones in any part of the body except the teeth. As the jaws are cartilaginous, when the animal dies, the ligaments holding the teeth together decay, and they separate, and thus we almost invariably find them scattered. In the present case, the jaw must have been imbedded in the firm clay, which retained the teeth in their regular position, as we now have them.
The specimens were submitted to the examination of Prof. O. St. John, who has made a special study of the fossil fishes. He discovered that the dental characteristics were so various in different parts of the jaw, that three species had been described from the size and variations of the teeth taken separately. He therefore erected a new genus on this head, called Agassizodus, calling this A. variabilis. So important does he consider our Kansas specimen, that the has had it engraved and inserted in the fourth volume of the Geology of Illinois, to illustrate similar fossils found in that State. See Plate VIII, of that volume. The jaw was nearly twenty-eight inches, which would indicate a total length of the fish from fifteen to twenty feet.
At the flagging quarries of Osage, several of the layers contain numerous footprints of reptiles. The deposit is above the middle of the Coal Measures, and about a dozen feet above the coal seam worked at Carbondale and Osage. The slabs or layers containing the foot-prints afford but few fossils, although there are numerous fucoidal impressions with ripple marks. I obtained one coprolite. But immediately above and below the flagging, are calcareous strata containing abundant remains of the usual marine fossils of the period. We selected thirty slabs, containing the foot-prints, for preservation, there being a few others too poor to pay for removal. Most of these contain but one set of tracks, but several contain two, of different species, and one has four sets. The most common, represented by more than half that were found, were large saurian-like tracks, in shape somewhat like Polemarchus gigans of Hitchcock. It differs in being but two-thirds as large, and in the proportional length of heel and toe. In our species the toes are nearly of equal length, five inches, and the heel four inches, making the total length nine inches. The width of the heel is five inches. There are some indications of a fourth short lateral toe. The length of the stride is from twenty to twenty-two inches; width of the trackway from center to center of the foot-print, is from four to six inches. There are about twenty slabs marked by this species, some of which are very poor. One large slab is at the State University, several at the Agricultural College, and several were sent to the Yale College collections.
The number of footprints on a slab vary from two to twenty. The tracks of this species vary very much in size, so much so that I was at first inclined to consider them two species, but I now class them as old and young individuals. On the largest slab the smaller (there being three rows of tracks) are half the size of the larger, and it will be no stretch of the imagination to suppose that in this case the mother was followed by her offspring. Over two hundred footprints of this species were preserved, and all found on one layer of four-inch flagging. They are all casts. The outline of the foot, in most cases, was distinctly defined. The reason that no direct footprints were discovered was very apparent. The layer on which the animal walked was a clay that did not change to stone, but crumbled on removal of the layer above; while the latter, being of fine sand and some lime, took the cast of the footstep and hardened to stone. For sidewalks this layer is very durable, and is in demand where large and firm slabs are desired. In several places on Kansas Avenue, Topeka, the slabs show where the raised casts of the footprints have been taken off by the stonemason to give an even surface. They can be seen on the large flaggings of several Kansas cities. Their relative position can be easily traced. This animal was evidently a true reptile and not amphibian.
In another footprint of a smaller animal, also a true reptile, the foot, measuring by the toes, was about two inches in length. The print of the heel was not left on the rock. The number of toes were five, counting the lateral spur, though usually only four were impressed, and sometimes only three. Length of the stride, twelve inches, and width of the trackway from center to center of the print, was six inches. This species was found on six slabs and on several solitary pieces at three different quarries. Some were also obtained by splitting the larger slabs from the old quarries, and in such cases the footprints and casts were, of course, both procured. In several cases the lobes of the toes are distinctly seen. The general impression left, after the study of this species, is that the animal must have been a clumsy reptile, combining some of the traits of both frog and salamander. The number of tracks seen on single slabs varied from one to sixteen, the total number of footprints being about two hundred.
The best and most distinctly preserved tracks are those closely resembling the Cheirotherium. These were all found at the "old quarry." They are very clear in the outline of the front toes, but the heel is obscure. The outline of the foot is from four and a half to five inches in width, and five and a half in length. The length of the stride is from twenty-one to twenty-two inches. The toes of the hind footprint usually cover the heel of the forefoot. We obtained both the true track and the cast. The width of the trackway is from eleven to twelve inches, measuring, as usual, from center to center. The front foot has four toes and the hind foot five, the fifth being short, or perhaps rudimentary. The footprint shows that the animal in walking rested his weight mostly on his toes, as these were clearly and strongly impressed, while the heel can be traced with difficulty. In several instances the print of the wrinkle of the skin on the under side of the foot could be seen. No trace of a claw was visible. In plumpness, the toe resembles the Cheirotherium, but the toes are more divergent. The track also resembles the foot of Sauropus Primevus, found in the Sub-Carboniferous of Pennsylvania, but is clearly that of an animal differing from both.
We procured twelve slabs of this species and a few single tracks. From four to sixteen footprints were found on each slab, numbering in all over one hundred. These footprints are as clear and distinct as the best of those found in the Connecticut Valley. They are sufficiently perfect to give the characteristics of the feet of these animals, and their mode of progression, from which they can be reconstructed.
We found also five small tracks, very much like those last described, measuring three-fourths of an inch in length by one and a fourth in width. These are not enough to decide the character of the animal.
These footprints are valuable from the fact that few are found west of the Alleghany Mountains. Their geological position, down in the Coal Measures, also adds to their scientific interest. A more technical description of these footprints, with drawings of the best slabs, will adorn some future State Report.
These footprints were first discovered on the flaggings of the streets of Topeka, and from thence traced to the quarries.
