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Geological Survey of Kansas (1896)

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Chapter V--A Geologic Section from State Line, Opposite Boicourt, to Alma, Principally Along the Osage River

by John G. Hall

Conditions near the state line Systems above Oread Limestones
The Iola Limestone The Osage City Shales, Coal and Limestone
The Garnett Limestone The Lawrence Shales
The Burlingame Shales The Oread Limestones
Systems above Burlingame Shales

This section starts on the eastern state line opposite a point about half way between Boicourt and Pleasanton, where the Osage river crosses the eastern line of Kansas into Missouri. From here it extends in a general northwesterly direction up the valley of the Osage river to its source, and thence across the divide into Mill creek valley, Alma being its terminus. It passes through portions of Miami, Franklin, Linn, Osage and Wabaunsee counties, and covers a distance of about 116 miles. Like all other sections within the Coal Measures of Kansas the rocks along it consist, of limestone, sandstone and shales, the latter predominating in amount.

Conditions near the State Line

Immediately at the state line the lowermost formation exposed to view is a heavy bed of shales which, being an eastward extension of the shales so abundant in the vicinity of Pleasanton, may be readily correlated with the Pleasanton shales; The base of these shales is not exposed at the state line, so their total thickness here could not be determined, but presumably they are little different from that at Pleasanton and Boicourt, which is given in chapter II as exceeding 200 feet. Above the Pleasanton shales limestones occur from the state line to Boicourt substantially the same as at the latter place. As these have been described in considerable detail hy Professor Haworth in chapter II, there is no necessity of repeating their description here. The peculiar topographic features of the country, however, may well be noticed, features which are dependent conjointly upon the heavy shale beds beneath and the protective limestone caps. The Osage has cut its channel through and far into the shales. In the vicinity of Osawatomie the westward dip of the limestones brings them so low that the bluffs are scarcely 100 feet high. But as the limestones rise to the east, and the stream descends in the same direction, the bluffs on each side of the river gradually become higher, until at La Cygne and Boicourt they are nearly 200 feet high. The Pleasanton shales decay rapidly and with great ease; the limestones above are persistent and strongly resist disintegration. In this way the sides or walls of the bluffs are steep, and sometimes are yielding so rapidly that vegetation cannot get a foothold. Sometimes also circular mounds are to be observed standing out in the broad valley entirely separated from the greater land bodies. They usually retain the limestone covering, and their sides are in every respect similar to the faces of the bluffs just mentioned.

The valley of the Osage river varies somewhat in width, but is from two to four miles wide. The stream itself meanders greatly within this valley, but the bluff lines approximate as great a degree of regularity as is usual for the bluffs of other rivers. The lateral tributaries entering the river at different places have cut their channel to a depth equal to that of the Osage river itself, and have similar bluffs bounding their valleys, the latter in some instances almost equal in width to the valley of the Osage river. This is well illustrated by Sugar creek. Its depth is equal to that of the river itself; the width of the valley is Dearly three miles, and it is bounded on both sides from Boicourt to Blue Mound by bluffs equalling if not surpassing those of the Osage river.

The Iola Limestone

As was shown in chapter II the uppermost of the limestone at La Cygne is the Iola limestone. From La Cygne it passes to the northward to Fontana and from Fontana dips slightly to the northwest, covering the surface of the country to beyond Osawatomie. At this place it covers the surface of the hill on which the insane asylum rests. Westward it can be seen all over the Pottawatomie valley to the vicinity of Lane, near which place it disappears beneath the Pottawatomie river. Along the Osage river its westwardly dip and the general rise of the surface cause it to continuously occupy relatively lower positions until finally it passes downward out of sight on the uplands in the vicinity of O'Brien, four miles to the west of Osawatomie, but it can be seen along the bluffs and the river valley much farther.

The Garnett Limestone

Just above the Iola limestone is a bed of shale known as the Lane shales, which is about 90 feet thick. These shales are of a light buff color shading in the lower half to a bluish gray, and in structure they are almost homogeneous, that is, they are of the same consistency throughout their entire thickness. After losing sight of the Iola limestone, four miles to the west of Osawatomie, and having passed over the Lane shales two new systems make their appearance simultaneously. These two systems are with difficulty separated when they first come into view, owing to the thinness of the bed of shales which lies between them. It is only 12 feet thick, and lias in it a great many small shell-like pieces of limestone, so that when exposed to the weather these are brought out so prominently they give the appearance of a continuous system of limestone. These two systems are called the Garnett limestones. The lower one is only 6 feet thick, while the upper one at its first appearance is only a foot to 18 inches, but gradually thickens as it extends to the west until it attains a maximum thickness of 30 feet. The upper Garnett limestone can be easily traced to Ottawa, at which place it is exposed on the north bank of the Marais des Cygnes river, while the lower one cannot be traced all the way but it is found in the bottom of the river underneath the wagon bridge that crosses it on Main street. At the crossing of the railroad and the county line between Miami and Franklin counties the Iola limestone lies five feet below the railroad track and the lower one of the Garnett limestones covers the top of the hills 50 feet above the track. In the uppermost of the Garnett limestones occur the Lane quarries, famous throughout the state for the so-called "Lane marble," which is a hard, gray limestone that is capable of taking a very good polish. At this place the limestone reaches a thickness of 45 or 50 feet, a local thickening where the conditions for the same were especially favorable. Here the dip of some of them is most extraordinary, being in some instances a foot or even 18 inches in a hundred feet distance.

The Lawrence Shales

Passing west from Ottawa one of the heaviest beds of shales in the whole section is reached. It corresponds with the heavy bed that is found so extensively around Lawrence, and has been called the Lawrence shales. They are particularly characterized by the large amount of sandstone they contain and the irregularity with which it occurs. Nowhere does it reach a high degree of perfection as sandstone, but frequently grades back and forth from a soft, friable sand rock into arenaceous shales. Almost every stream that has cut a deep channel into the shales has bluffs of such sandstone here and there throughout its course. A prominent one of these occurs on the south bank of the Marais des Cygnes river, about 10 miles west of Ottawa, in the vicinity of Pomona. Here above the heavy bed of sandstone the formations bear good evidence of having been produced in marginal areas, or shallow water lagoons, for the shales pass into sandstone and back into soft shales with great frequency. The upper sandstone is hard, and has an appearance very like limestone. The surfaces of the different layers are covered with ripple marks and wave marks, which are made more apparent by weathering. Some of the sandy shales are quite firm and hard, but are so perfectly laminated that they cleave with great perfection parallel to the bedding planes. Upon weathering, however, they produce very irregular surfaces, the ripple marks being remarkably pronounced and exceedingly intense.

The Lawrence shales, like most heavy shale beds in the state, have in them seams of coal which are of so good a quality that they are mined and put upon the market. The principal mines are located in Franklin county, the coal from which in commerce is known as the "Franklin county coal." It is placed upon the markets of Ottawa and neighboring towns, and to a limited extent freighted to other parts of the state. Near the outcroppings of the coal seams the mining is conducted by the ordinary "stripping" process, but in a few localities, particularly near Pomona, the shafting method is used. The Franklin county coal, seams vary in thickness from a few inches to a maximum of 2 feet. It is found at different horizons within the shales, but the heaviest veins are found near their base. To the north of the limits of this section, in Douglas county, coal also is found in the Lawrence shales, the details about which are given in chapter VII.

Along the line of this section the Lawrence shales are considerably oyer 100 feet thick, so that their southeastern limit produces strong physiographic features. The protection of the overlying limestone in connection with the soft character of the shales in certain localities produce exceedingly rugged bluffs, while in other places the interbedded sandstone is sufficiently abundant to resist erosion to so great an extent that almost no escarpments are produced, Occasionally a circular or oblong mound exists a few miles to the southeast, having been in some way preserved while the remainder of the surrounding material was worn away in the production of the valleys.

The Oread Limestone

Above the Lawrence shales two systems of limestone are found, the Oread limestone, separated from each other by from 12 to 15 feet of shale. The lower of the two is about 15 feet thick; the upper one when first found is eroded away almost to a thin edge, but soon thickens to 18 or 20 feet.

Systems Above the Oread Limestone

The first limestone system above the Oread limestone appears 10 miles west of Ottawa, and is 4 feet thick covering a shale bed 50 feet thick. The general appearance of the limestone is much like that of the Oread limestone and would make good building stone. The shales below this limestone are buff in color and generally soft, and hence yield to the weathering agents quite readily, but some, times they turn into a brown sandy shale which is very coarse, instead of being composed of the usual fine particles that generally make up the shales.

Following up the river another limestone, No. 2, is reached a mile west of Quenemo, and is 5 feet thick, covering a shale bed of 20 feet. It is composed of two layers of almost equal thickness and is of a grayish yellow color and quite hard. The shale bed has so many thin layers of sandstone, which are made up almost entirely of silica, that it wears away nearly as slowly as the limestones. The layers of silicious sandstone are none of them more thun 2 or 3 inches thick, while most of them do not exceed half an inch.

Six miles to the northwest of Quenemo system No. 3 crops out, which is 10 feet thick, the upper 4 feet of which is brown in color, while the rest is almost white. The whitish portion contains one layer about a foot thick which is composed of fossil fusilina, the shells of which are about the size and shape of a medium-sized grain of wheat.

The Osage City Shales, Coal and Limestone

Six miles southeast of Burlingame system No. 4 crops out, but can only be traced a short distance until it is lost to sight. It is 15 feet thick, and corresponds so closely with the one found over the coal at Burlingame both in thickness and general structure that there can be little doubt but that it is the same system. It is 60 feet above No. 3, and is of a grayish white color. It is very soft, and therefore easily worked, but not used much on account of its softness.

The coal found at Burlingame is from 75 to 90 feet below the surface of the ground, depending on the position of the shaft. There is a broad almost level strip of country extending over nearly the whole of Osage county, underneath which the coal is found. The coal varies in thickness from 18 inches to 3 feet. It is mined at Osage City, Scranton, Burlingame, and Peterton, and formerly was mined at Carbondale, but these mines have not been worked for some time. The whole country is dotted with coal shafts, some of which are worked only for private use, while the majority are worked and the coal put upon the market.

The Burlingame Limestone

Just west of Burlingame system No. 5 makes its first appearance. It is 8 feet thick, is brown in color, shelly in character and covers the third and last heavy bed of shales in this section. The shale bed is 150 or 200 feet thick, and throughout it are found thin beds of limestone which tend to cause the shales to resist erosion. Here, as with all other thick beds of shale, are a number of isolated mounds which are covered with limestone that corresponds in general so closely with that found on the main bluffs one cannot help believing they are the same system. These mounds are most numerous to the north of Burlingame, and differ in height from 50 to 125 feet. The most important one is about two miles from Burlingame and is 85 feet high, and covers an area of almost a square mile.

Systems Above the Burlingame Shales

Four miles west of Burlingame another limestone, No. 6, makes its appearance. It is 10 feet thick and 40 feet above No. 5. It has a dark yellow color where it has been exposed to the weather and breaks up into almost square blocks, due to the prevalence of vertical seams. The shale beds beginning with this one. from now on to the end of the section are so thin and so similar and almost identical in character that no description of them seems necessary, except the one that occurs above the system that is known as the Cottonwood Falls rock, which will be described in its proper place.

The next system, No. 7, appears one mile northwest of Harveyville, and is 8 feet thick. It has a dark brownish yellow color, and when exposed to the weathering agents becomes quite shelly. The limestone can easily be traced to the northwest until it is covered by the next system.

No. 8 is seen on the northwest of Harveyville. It is of a grayish white color and is composed almost entirely of well-preserved brachiopod shells, none of which are more than half an inch across. The system is only 3 feet thick and is 20 feet above No. 7.

After losing sight of No. 8 there appear three systems: No. 9, which is shown four miles southeast of Eskridge, and is only 2 feet thick; No. 10 appears one-fourth of a mile back from the edge of No. 9, and is 3 feet thick. The third of these systems is No. 11, and is only a foot thick, and is light gray in color. These three systems are all found in a rise of the ground of 150 feet.

One mile east of Eskridge system No. 12 makes its appearance. Its thickness could not be determined here, but the next higher one was traced across the hills into the Kansas river valley and the thickness of system No. 12 was found to be 15 feet, and was 20 feet above No. 11.

Just east of the railroad station at Eskridge system No. 13, which is known as the Cottonwood Falls rock, makes its first appearance. With the advent of this rock there comes in a change in the general character of the limestones. They become very white, and instead of breaking into small pieces when exposed to the weather they seem to wear away gradually and almost regularly, that is about equally in all parts. The system is 6 feet thick and has two layers of almost equal thickness and is used throughout the state for building purposes. In it there are three rows of flints which do not wear away as rapidly as the rest of the rock. It can easily be traced to Alma or the end of the section. Above it in the shale bed there are found an unusually great number of fossils, mostly brachiopods and a few short pieces of crinoid stems and a few spines of sea urchins. These fossils are all found in the lower six feet of a shale bed of 15 feet.

Above this system there are yet three others, the first of which, No. 14, is 3 feet thick and where exposed weathers white. The next system, No. 15, is 30 feet above No. 14, and weathers white the same as the preceding ones. The next and last system is No. 16, and can only be found on the tops of some of the highest points of the bluff. It is 20 feet above the last one and is 3 feet thick in one or two places. It weathers white with the exception of, a number of very fine black specks. The last four systems can be traced from Eskridge to Alma because they are exposed on the sides of the precipitous bluffs.

Plate V--A Geologic Section principally along the Osage river from the east line of the state to Alma.

By John G. Hall; to accompany Chapter V.
Scale: Vertical, 1 inch equals 500 feet; horizontal, 1 inch equals 5 miles.
The limestones are represented by the conventional masonry. The Shales and sandstones are left bare.
The contours are almost entirely taken from the United States Geological Survey Topographic sheets.
Available as an Acrobat PDF, 1.5 MB.


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Kansas Geological Survey, Geology
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