Seventeenth Annual Meeting. 109 



from the water, except where the beds have been since locally altered, to a limited ex- 

 tent, by rivers and other streams of water cutting through them. 



1 am aware that erosion and changes in the elevation of land, of continental extent, 

 occurred during Post-Tertiary time, but it is not probable that all the changes happened 

 at the same time, and we must look to the respective changed localities to determine the 

 relative ages wlicn this work was done. 



In this paper 1 have considered southeastern Kansas only, and have attempted to 

 sketch the condition of tilings wrought out by natural forces in it. 



IN THE DACOTA H. 



BY ROBERT HAY. 



Across central Kansas, from north to west of south, stretches a belt of country, 

 marked in ravines by rugged sandstone rocks, and by long-rounded slopes on the prairie. 

 This belt belongs geologically to the lower part of the Cretaceous system, known as the 

 Dacotah formation. To travelers on the Central Branch Railroad, passing through 

 Washington and Cloud counties, these sandstones are conspicuous objects. On the line 

 of the Kansas Pacific, the same sandstones, underlaid by colored shales, make the wild 

 country from Bavaria by old Fort Harker to Ellsworth. On the Santa Fe Railroad, a 

 single hill standing out in the broad valley of the Arkansas, covered on its precipitous 

 front with names of visitors — archdukes and naturalists — a hill of varied sandstone, 

 capped with chalk, is the sole mark left by the tremendous erosion of a million years 

 that here too the Dacotah formation occupied its place. Away north in Nebraska and 

 to British America, away south in the Indian country and Texas, the same sandstones 

 appear. The same, but varied — varied, but still the same. 



At our northern State line, the surface-development of the Dacotah is about thirty 

 miles across, forming the bluffs of the ravines on the west side of the Little Blue, and 

 disappearing under the Inoceramus limestones of the Benton series in the west of Wash- 

 ington county, north and south of Haddam. Further south, the belt is wider, in some 

 places exceeding fifty miles. This is probably due to a greater slope of the surface in 

 the south, in past ages, causing greater erosion of superincumbent deposits. 



The hill in the Arkansas valley is forever wedded to a tale of terror. It is the fa- 

 mous Pawnee Rock. But a little shred chipped from it tells another story. It is 

 marked with the remains of an ancient flora. Further north, in Ellsworth county, are 

 ravines with precipitous sides, on some of which a lost race has carved hieroglyphics of 

 war and travel ; and there are huge single rocks, like giant pulpits, standing out and 

 alone. In Ottawa county are the worn pinnacles and crags of Rock City. In Washing- 

 ton county the bold sandstone cliffs are seen resting on permian limestone, while their 

 upper surfaces have been ground by the huge hard boulders of the glacial age. And in 

 all these places are the relics of the Old World flora leaves — dicotyledonous leaves. 

 < >ther of our counties have them — Clay, Cloud, Saline — and they are found away north 

 and south far beyond our borders. Professor Mudge and others have estimated the 

 thickness of the Dacotah at about five hundred feet, and this thickness is composed 

 mainly of sandstones, those near the top in most of the exposures we have seen, being 

 light-colored, and the lower ones dark brown or red. In some places it is blood red, 

 streaked with yellow; and when the sun shines on it we have a gorgeous glory. The 

 coloring-matter is largely composed of some compound of iron, and in places this 

 has oxidized in most curious forms, suggesting by their vitreous surfaces the action of 

 fire. In many places we have picked up specimens with a botryoidal surface not to be 

 distinguished from kidney hematite from Europe and elsewhere. Then there are nodules 



