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II ^— CRETACEOUS SYSTE:\r. 

 1.— NlOBEAEA. 



2.— Dakota. 



The Cretaceous ia Kansas covers an area of over forty thousand 

 square miles, or more than half of the surface of the State. The Pierre 

 and Fox Hill groups of Haydeu, and all equivalents of those periods, 

 are entirely wanting. The Benton gronp also appears to be absent. 

 The Cretaceous is, therefore, represented in Kansas by the Niobrara and 

 Dakota only. The line of demarkatiou between the Pliocene and Creta- 

 ceous is well defined and sharp. Adjoining the Permian easterly, it is 

 not so clear ; yet some recent examinations, made in company with 

 Prof. O. St. John, show that the boundary is not difficult to trace. We 

 have never been able to find any fossils of the Jurassic or Triassic, the 

 beds of the Cretaceous resting conformably or nearly so on the Per- 

 mian. 



That portion south of the Arkansas River has been little examined, 

 either by myself or others, but appears to be represented by the Fort 

 Hays and Dakota groups. 



1. — Niobrara. 



a. — Xiohrara. 



b. — Fort Hays. 



The Niobrara, or its equivalents in time, is well represented. It is 

 divided into two clearly-defined portions, by a massive bed of limestone 

 or yellow chalk, which when fnlly exposed, where it has not suffered 

 from abrasion, is GO feet in thickness. It is seen in the valley of the 

 Smoky, southwest of Fort Hays, as well as seven miles west of that 

 place, and at various points to the northeast, crossing the Solomon juf^t 

 above the Forks, near Osborne City, and entering Nebraska in Eepub- 

 lican Yalley, near where that river crosses the State line. It is com- 

 posed of layers of yellow chalky limestone, from 1 to 3 feet in- thick- 

 ness. It makes an excellent building-material, working easily, yet 

 sufficiently compact to be used for stores or dwellings. At 

 Hays, the school-house and court-house are built from it; and ten 

 miles west of that place the Kansas Pacific Eailway has opened a 

 quarry for supplying stone for use along its line. It also burns to a 

 good quicklime. The massiveness and persistence of this stratum 

 make it a well-defined geological horizon. Below this line, as well as 

 in it, vertebrate fossils are few, while above it they are numerous and 

 of varied type. Its fossils are Inocerami, fragments of Saploscapha, 

 Ostrea, with occasional remains of fish and Saurians. The vertebrates 

 are always so rare that we never wasted our time in hunting them in 

 this stratum ; still our largest Saurian, Brimosaurus of Leidy, was found 

 in it in Jewell County. 



a. — Xiohrara jjroper. 



The Niobrara in Kansas differs from the same deposit on Niobrara 

 Eiver. The upper j)ortion, which we shall call Niobrara proper, or sim- 

 ply Niobrara, is very unlike the lower, which shades imperceptibly into 

 deposits like the Benton. The two divisions differ in a very marked 



