122 KANSAS ACADEMY OF SCIENCE. 



beds of Benton shales underlying the resistant limestones are known 

 as the Blue Hill shales, from the same locality. It is the erosion of 

 these beds which gives rise to the escarpment. 



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 part of the Cretaceous system 

 known as the "Dakota formation." To travelers on the Central Branch railroad, 

 passing through Washington and Cloud counties, these sandstones are conspicu- 

 ous objects. On the line of the Kansas Pacific, the same sandstones, underlain 

 by colored shales, make the wild country from Bavaria by old Fort Harker to 

 Ellsworth. . . . Further north, in Ellsworth county, are ravines with pre- 

 cipitous sides, on some of which a lost race have carved hieroglyphics of war and 

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

 alone. In Russell county are the worn pinnacles and crags of Rock City, and in 

 Ottawa county the quaintly rounded concretionary masses of another rock city. 

 . . . (Hay, 8th Bien. Rep. Kan. St. Bd. of Agri., vol. XIII, pt. II, pp. 109, 

 110, 111.) 



A large portion of western Kansas is included in the High plains. 

 Their eastern boundary is defined by the Blue Hills escarpment in 

 the northern part of the state. South of the Arkansas river they 

 merge with the undissected western margin of the Red Hills upland. 

 The western limit of the High plains lies well toward the foot-hills of 

 the Rocky Mountains, in Colorado. Their north and south extent has 

 not yet been defined with any degree of definiteness. They corre- 

 spond with what has sometimes been called, for convenience, the Cen- 

 tral plains, and form an irregular belt midway in the long eastward 

 slope of the Great plains. They are characterized by a general dead- 

 level surface when viewed in their broader aspect. Thei;* surface is a 

 constructional plain, which has survived in large measure since the 

 close of Tertiary times. The divides between the streams are flats or 

 fragments of an extended surface which was formed by the spreading 

 of a quite even mantle of Tertiary sediments over the older rocks, 

 which are principally of Cretaceous age. The valleys, which are 

 scored into the Tertiary and often expose the Cretaceous, are relatively 

 but slight furrows compared with the broad extent of level land. 

 Along the larger streams, however, are found occasional striking 

 erosional forms, which are all the more conspicuous because of their 

 occurrence in the High plains. Cretaceous formations, which are ex- 

 posed where the rivers have cut through the Tertiary beds, give rise 

 to canon walls along the small tributaries, and in the broad valleys 

 remnants of them occur as bluffs and standing rocks. The Dakota is 

 seen at Point of Rocks, on the Cimarron river, in Morton county, and 

 the bluffs on Bear creek, in Stanton county. The Benton and Fort 

 Hays limestones occur along the bluffs of the Arkansas river and its 

 tributaries in Hamilton county. The Niobrara, however, gives rise 



