22 University of Kansas Geological Survey. 



them. The Cretaceous is made up of at least three divisions — 

 the Dakota, Benton, and Niobrara ; the upper members appear 

 to be absent. He says concerning the Benton that certain 

 limestones, if indeed they are not to be relegated to the Nio- 

 brara, afford stratigraphical evidence upon which to base the 

 limits of the western exposure. He estimates the total thick- 

 ness at 2200 feet. He says concerning the shales at the top of 

 the Niobrara, that they strongly resemble the " Colorado shales," 

 i. e., Fort Pierre and Fox Hills. He says that the salt springs 

 and wells of the Cretaceous are probably supplied from, the Car- 

 boniferous deposits. To the south of the Arkansas valley, hori- 

 zons discovered by G. S. Chase are characterized by a molluscan 

 fauna which indicates affinities with the Texas Cretaceous 

 fauna. 18 He believes that the Cretaceous has been eroded pro- 

 gressively more deeply toward the east, so that the Tertiary 

 rests upon successively lower beds toward the east. 



1887 — St. John. 19 In southwestern Kansas only the Dakota 

 and Niobrara have been identified with certainty. Beds now 

 known to belong to the Comanche series are here described as 

 Dakota. Those described by him as Niobrara are referred since 

 to the Benton. 



1888 — Hay. 20 From the north boundary of the state to Mc- 

 Pherson county the Dakota sandstone rests upon the Permo- 

 Carboniferous, an example of erosive non-conformability. 

 From McPherson county south the Triassic beds intervene. A 

 shorter period of erosion appears to have taken place there. 

 The Dakota is from 300 to 500 feet thick. The passage to the 

 Benton is without break, the beds being absolutely conformable. 

 Total thickness probably does not amount to 400 fe^et. The 

 Niobrara consists of two conspicuous strata, a succession of soft 

 limestones, beneath which is a thick shale bed containing con- 

 cretions. This shale, with occasional intercalations of lime- 

 stones, is 100 to 300 feet in thickness. The limestones do not 

 reach 100 feet. The Fort Pierre and Fox Hills appear to be ab- 



18. Probably the first reference to the Lower Cretaceous in Kansas. 



19. Notes on the Geology of Southwestern Kansas, Fifth Bi. Rep. Kans. St. Bd. Agr., 1885-'86. 



20. Sixth Bi. Rep. Kans. St. Bd. Agr., 18S7-'S8. 



