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Geological Survey of Kansas (1896)

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Chapter XIII--Surface Gravels of the Carboniferous Area

by Erasmus Haworth

Geographic Location of Gravels
Previously Expressed Views
Results of Present Investigations

Geographic Location of Gravels

Perhaps no county in the eastern part of the state is entirely free from surface deposits of gravel which are radically different in character from those further north belonging to the glacial deposits, and from the various Tertiary gravels found in different parts of western Kansas. The glacial gravels are found in the northeastern counties, but are unknown over the greater part of the state. The gravels under discussion are composed almost entirely of flint, or chert, and are often fossiliferous. They vary in size, ranging from the size of a pea to five or six inches in diameter. Their shape is rounded, but often decidedly angular, and occasionally they have sharp, cutting edges. In color they range from the light chalcedonic varieties through different shades of yellow and red to dark, as river gravels usually do when stained with iron which is in various stages of oxydation. The light buff color greatly predominates.

They are found in beds of various dimensions, and in different positions with reference to the surface. Sometimes they form only a little sprinkling on the surface; sometimes they form heavy beds from 2 to 3 feet thick at or near the surface and at other times they are buried from 10 to 20 feet beneath a surface soil. Their position is as varied as the surface of the country where they occur. They are found in the creek and river beds, along the banks of the streams, underlying the rich soils of the valleys, on the uplands and divides, and finally on top of the highest hills in the country.

Geographically they extend from north to south, from east to west, not over all the surface, but so extensively that one may not be at all surprised to find them at any particular place. They are found in great abundance at the northern edge of Ottawa, and almost all along the Atchison, Topeka & Santa Fe railroad from that point to beyond Independence. They are abundant on both sides the Neosho river from its source to its point of leaving the state, and are much more abundant along the Cottonwood river. The court-house at Cottonwood Falls stands on a hill covered with gravel to the depth of 10 feet or more, and they abound for miles in every direction. The most extensive deposits of gravel anywhere in the state are found in the famous Flint Hills area lying between the Walnut and Verdigris rivers near the south line of the state. Masses of flint varying from 2 to 3 feet in diameter to those of small size are so abundant that the name is generally considered to have been well chosen. Gravel in greater or less abundance is found on the surface all the way from the Cottonwood river; which determines the northern extension of the Flint Hills as the term is usually applied, to far beyond the Kansas river to the north. Cursory examinations made from time to time during the past 15 years indicate that similar gravel deposits are found to the south in the Indian Territory and to the east in Missouri, occupying indiscriminately the surfaces of Coal Measures and Mississippian formations. The character of the gravel is largely the same all over the areas mentioned, and the modes of occurrence cannot be discriminated.

Previously Expressed Views

Such interesting formations as these gravels constitute have naturally attracted the attention of different geologists at various times. One result is that quite a literature has accumulated on the subject, in which one can find many different views on the origin of the gravel and mode of formation of the beds. Without attempting to give an exhaustive review of such literature, a few references to various articles on the subject may be of interest in this connection. In 1874 Prof. G. C. Broadhead, in describing the surface deposits of Jasper county, Missouri, wrote as follows (Missouri Geol. Sur. Rep., 1873-74, p. 179):

"The material overlying the solid rocks may be referred to local agencies. Solid beds of rock often appear on high ground, and can always be reached within a few feet of the surface. The soil and subsoil, both combined, are not often over 2 feet deep, with downward successions of red clay and gravel for from 4 to 8 feet, to solid rock. The gravel is even sometimes at the surface, and often within a foot depth. It similar succession of loose material is also commonly found at the lead mines. The banks of the streams, also, are similar, of which Center creek exhibits:
No. 1.—1 1/2 feet dark soil.
No. 2.—2 feet red clay.
No. 3.—3 feet gravel bed to the water in creek.
"On the prairie two miles to the southwest of Carthage excavations show water-worn chert pebbles at the surface. At the old mines in section 33, four miles southeast of Carthage, similar pebbles were observed. These were found 60 to 70 feet above Spring river or Center creek; so it is quite evident that no recent agency could have deposited them there. They must therefore belong to the Drift, about its southern limit, but born by currents from some place near by."

In speaking of the surface deposits in Vernon county, he writes (Missouri Geol. Sur. Rep., 1873-74, p. 121):

"Undoubtedly this country has been subjected to glacial agency at some former period of time. Its results may be seen in the isolated mounds and deep valleys between. The amount of erosion must have been of great force and of long continuance, if we view the mounds and long stretches of distance from one to the other. No drift pebbles were seen on high ground, but some wells exposed rounded gravel and sand. Near Nevada, I heard of a gravel bed containing logs, etc., in a well 16 feet below the surface."

Similarly when describing Bates county Professor Broadhead says (Missouri Geol. Sur. Rep., 1873-74, p. 156):

"That this county has been at some former time subject to extreme denudations is evident from the isolated mounds often seen. Their summits are probably of the same elevation as the higher ridges in the eastern part of the county. There has been a scouring from north to south, leaving isolated mounds protected from destruction by cappings of limestone. The force of the glacial action which has caused this has been such as to bear away all drift pebbles from the surface excepting when on the higher grounds. On the mounds east of Pleasant Gap are often seen quantities of rounded gravel, mostly silicious. The banks of Camp creek have exposed at one place a bed of similar gravel with sand. At Burnett's ferry the banks of the Osage show:
No. 1.—Soil.
No. 2.—12 feet brown sandy clay.
No. 3.—10 feet blue clay.
No. 4.—Bed of rounded silicious gravel."

Later Professor Broadhead referred to the surface gravels of Kansas in different articles published in the Kansas City Review, in which he gives a good description of their geographic positions, emphasizing the fact that they so often occur on the highest hilltops (Kansas City Review of Science and Industry, vol. 3, p: 460, and vol. 8, p. 453). He refers the age of the gravel to the Coal Measures, but that of the gravel beds to the "Later Glacial." It will thus be seen that Professor Broadhead, whose observations have been very extensive, attributes the origin of the gravel to the local formations for both the Missouri deposits, and the origin of the beds or layers to the later glacial action. In this respect his views are similar to those of St. John, as is shown by the following quotations (Report Kansas St. Bd. Agr., 1881-82, p. 598):

"To the latter [the modified drift] belong the ordinary superficial deposits spread over the southeastern portion of the state, among which no vestige of true glacial erratics . . . have been detected, whose accumulation was due to the denudation and disintegration of the limestone, sandstone and shaly deposits occurring in the region where they exclusively constitute the evidences of the action of powerful denuding agencies, which may, with much reason, be identified with the Champlain epoch."

In a later publication he writes (Private letter to Prof. J. D. Parker published in Kansas City Review. vol. 8, p. 386, 1884):

"In regard to the chert gravel from the Neosho valley near Burlington, Kas., it is perfectly safe to say it comes from the chert beds overlying the heavy building limestone series, well up in the Upper Coal Measure series. . . . It may not be strictly a 'glacial' gravel, although these particular deposits might well have in part been the result of glacial agencies; but they are to be regarded as of local origin, as we can distinctly trace them to their native ledges only a few miles to the west or northwest of their present position in the gravel deposits. . . ."

From fossils contained in the gravel, St. John decides they are identical in age with the Coal Measure rocks, many of which contain large amounts of chert.

Professor Mudge, who was so familiar with Kansas geology, visited the Burlington gravel beds in 1871 and expressed the opinion, according to Parker, that they were the result of "modified drift," whatever that may mean (Private letter to Prof. J. D. Parker published in Kansas City Review. vol. 8, p. 386, 1884).

The gravel beds in the vicinity of Burlington years ago attracted considerable attention, and an effort was made to introduce the gravels for paving streets, walks, etc. In this connection Prof. J. D. Parker published a number of articles giving descriptions of the character and extent of the deposits. He also sent samples to different scientists and civil engineers, thereby hoping to gain in format jon regarding their age, mode of formation, economic importance, etc. Prof. C. F. Chandler, of the Columbia College School of Mines, wrote that the character of the gravels was such that they would do excellently for macadamizing. Different physicians recommended their use from sanitary standpoints, their color being preferable to that of limestone, which reflects the sunlight to so great an extent that it is objectionable for street-paving purposes. City engineers advised their use for street paving on account of their great durability, so that it looked for a time as though an industry of considerable proportions might spring into existence. Prof. C. A. Shaeffer, of Cornell University, now president of Iowa State University, to whom samples were sent, reported the character of the pebbles, as already given, and added that he had succeeded in identifying included fossils as belonging to the two genera Fenestella and Trematopora. From this fact he decided that the gravel belonged to the Silurian period. But as these genera extend from the Silurian to the Coal Measures their existence by no means is at variance with the views of others who refer the gravel to the Coal Measures.

In 1884 Judge E. P. West read a paper before the Kansas Academy of Science entitled, "The Last Submergence and Emergence of Southeastern Kansas from the Carboniferous Seas, or those Effecting the Carboniferous Formations in Kansas," in which he attributed the present topography of the eastern part of the state to the relatively modern submergence below the sea level, during which time, he thought, the valleys were eroded, the terraces formed, and the gravel beds produced. [Published in Kansas City Review, vol. 8, p. 477, and also in Trans. Kas. Acad. Sci., vol. 9, p. 106.] In this paper he was unable to fix a date for either the beginning or ending of the submergence, but subsequently he decided that the period was the same as that portion of the glacial period during which the Loess was deposited along the Missouri river, and that the submergence involved nearly all of Kansas and parts of Nebraska, Iowa, Missouri, Illinois, Arkansas, Louisiana, Indian Territory, and Texas (Kansas City Review, vol. 8, p. 566). He admits, however, that no trace of marine deposits has been found over this vast territory, and seems to rely wholly upon the extent of erosion, and the gravel and other surface deposits for the evidence of such a wide-spread submergence. How well this accords with the generally accepted views of erosion the reader can judge.

Results of Present Investigations

It will be seen from the foregoing that the prevailing opinion has been that the gravels themselves originated in the Coal Measure limestone, and that the accumulation of the beds was in some way connected with the glacial period, probably with the heavy floods produced by melting ice.

Our labors the past three summers have demonstrated a few points which may have an important bearing on the subject. First, we have become convinced that chert has such a wide-spread distribution in the different limestone systems of the state that transportation has been necessary in but few instances, possibly in none. Could the limestones as now seen be dissolved in a day, the amount of chert left behind would be surprisingly great. Scarcely a single system has been studied carefully which did not contain surprisingly large amounts of it. The lead-bearing limestone of Galena has sufficient chert to produce beds of gravel a fourth as thick as the limestone system. The Erie limestone is particularly, filled with chert, as may readily be seen wherever it is exposed. Along the west bank of the Neosho river for a few miles below Austin is a splendid place to make such observations. Chert nodules of many shapes and sizes are here to be seen in great abundance. They are uniformly filled with seams, which in position are entirely independent of the fissures in the inclosing limestone, When they weather out of the limestone they fall into many fragments, corresponding in size very well with the gravel near by. The middle system of the three carries the largest quantities of chert, as Bennett has described in chapter IV. The whole surface of the country where this system is exposed is almost completely covered with gravel, some of which on the prairies east of Portervale a few miles are large boulders measuring in extreme cases 3 feet or more across. It is a conservative estimate to place the amount of chert in this one system at a quantity sufficiently great to make a gravel bed fully 12 inches thick over the whole surface now covered by the limestone, provided it could be freed from the matrix all at once. The upper member of the Oread limestone likewise has large quantities of chert within it, and the surface gravel, as noted, is correspondingly great over areas from which the limestone has been eroded. Passing westward, the next limestone system particularly noted for the flint it carries is a heavy system first observed along the Cottonwood river--as shown in plate III--capping the hills about two miles west of Strong City. It lies about 150 feet above the Cottonwood Falls limestone, and constitutes a system reaching from 25 to 30 feet in thickness. Flint masses are remarkably abundant in the limestone, so much so that in different localities it constitutes from a fourth to a third of the entire mass. A quarry is opened at this place and the rocks crushed for ballast along the Atchison, Topeka & Santa Fe railway, thousands of car-loads of material being used in this way. Above this about 200 feet another heavy limestone is found which likewise carries immense quantities of flint. It is quarried at Florence and portions of it crushed for ballast the same as at Strong City. To the north of the Cottonwood river the same two systems extend all the way to Junction City and probably much farther. Throughout the whole of this area the surface is everywhere covered with gravel deposits of varying amounts. Southward from the Cottonwood river area the two limestone systems extend into the Flint Hills region, and unmistakably have furnished the greater portion of the flint so abundant in that locality.

It may be stated that not a single limestone system of any considerable importance has been found in the whole of the Coal Measures which did not carry a perceptible amount of flint. Those just enumerated are the ones which have it in the greatest degree.

In the second place it has been observed that the gravel usually is most abundant in the vicinity of a limestone system rich in chert, or in places over which such limestone probably extended. The gravels about Oswego occupy space undoubtedly covered at one time by the Erie limestone; those so abundant about Cottonwood Falls lie under the earlier extension of the system just described, which carries so much chert. On the other hand, the area where the surface is most nearly barren of gravel are always areas farthest removed from chert-bearing limestones. Of these the Cherokee shales area in Cherokee and Crawford counties is the most prominent, for no other area equal in extent has been observed which is so entirely free from gravel.

In the third place, we found that many of the rounded surfaces possessed by the gravel are the original curved forms the cherts possessed while in their limestone hosts. This is particularly noticeable at Cottonwood Falls. Countless numbers of these have unmistakably such rounded forms. Some were found with traces of the limestone still adhering, others with the curved surfaces still possessing the rough character the chert surfaces have while in the limestone, and which in no particular resemble water-worn surfaces. The angular parts of the chert often have been worn little more than one would expect to observe on chert masses which had been subject to the weathering agents for long geological periods with such slight movements as might well be attributed to local causes.

It may well be argued, however, that ordinarily the gravels have been transported but a short distance if at all. Wherever they are found there is always an intimate mixture of the large and the small, sometimes with variations from half an inch to 10 or 12 inches in diameter. This alone is sufficient to show that they have never been subjected to the sorting power of water; for sand and gravel which have been transported by water are always more or less graded into relatively uniform-sized grains in any given locality.

It seems very probable, therefore, that in most instances the surface gravels of eastern Kansas have been derived from the native limestone systems, and that they are the direct results of the weathering of those limestones which, when dissolved and carried away by solvents, have left behind the less soluble chert. The chert boulders of such varied sizes and shales fell into fragments on account of the numerous fissures everywhere prevalent, and the gravel was the result. As terrain after terrain yielded to the slow but sure processes of disintegration and destruction the insoluble chert formed residual products which gradually settled to the lowest level possible, which may have been the summit of a hill, or the bed of a river, or any intermediate position. Here and there the rolling down the hillside, the being moved by water in times of floods, the abrasive effects of moving soil and sand produced by wind or water, rounded the edges and blunted the sharp angles, in some places more than in others. Similarly the gravel has accumulated, now in broad, even layers, then in windrow-like masses formed by irregular surfaces and unequal amounts of the chert in the limestone. If there ever was a period during which Kansas was flooded by water from the melting glaciers such waters of course would assist in working over and arranging the gravel into beds. But it can hardly be argued that the gravel beds of themselves predicate the former existence of such water in Kansas territory.

This view is believed to be in harmony with the generally accepted views of leading geologists regarding the origin of many other formations of similar character. Surface gravels are present in many different parts of the world. They cover the highest hilltops of our great mountain systems and fill the deepest valleys. Altitude seems to have no effect upon them. They were perplexing in the extreme until geologists began to look upon them as being only residual products left behind when the more perishable materials passed away.

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Kansas Geological Survey, Geology
Placed on web June 1, 2017; originally published 1896.
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