THE FLORA OF THE CHEYENNE SANDSTONE OF KANSAS. 



By Edward Wilber Berry. 



INTRODUCTION. 



The present study is based on collections 

 made by Hill in 1894, Ward and A'aughan in 

 1896, Ward, Gould, White, and Cain in 1897, 

 and Lee in 1919. These collections were very 

 extensive, but the bulk represented small 

 fragments of the more abundant species, such 

 as the Sequoia and Sapindopsis. The flora 

 itself as at present kno\vn consists of a very 

 small number of species. 



The Cheyenne sandstone comprises about 

 100 feet of gray to yellow friable quartz sand- 

 stone with subordinate lenses of dark shale. 

 The sandstone ranges from fine to coarse and 

 contains a few layers of quartz and chert 

 pebbles. It is in the main only slightly 

 consolidated and is very friable and easily 

 eroded. The bedding is extremely irregular 

 and discontinuous, and cross-bedding is obvious 

 throughout and in places extremely pronounced. 

 Logs of silicified wood and CycadeoiJia minuta 

 from these beds were recorded by Cragin.' 



The Cheyenne sandstone rests upon " Red 

 Beds" of supposed Permian age and is over- 

 lain by the Kiowa shale — shallow-water and 

 lagoon deposits of alternating layers of marl 

 and bituminous clay shale, with a marine 

 fauna that includes many species character- 

 istic of the Washita group of the Texas Cre- 

 taceous. 



The invertebrates are said by Twenhofel to 

 number about 50 species, of which the follow- 

 ing are some of the commoner forms: 



Cardium kansasense Meek . 

 Cyprimeria kiowana Cragin. 

 Exogyiti texana Roeiner. 

 Gryphaea comigata Say. 

 Gryphaea na\'ia Hall. 

 Ostrea quadriplicata Shiunard. 

 Pecten te.xanus Roemer. 

 Protocardia texana Conrad. 

 Schloenbachia belknapi (Marcou). 

 Schloenbachia peruviana (Von Biich). 

 Trigonia emoryi Conrad . 



' Cragin, F. W., Washburn Coll. Lab. Nat. fflst. BuU., vol. 2, pp. 

 35-66, 1889. 



In some places the Tertiary overlies the 

 Kjowa; elsewhere the following units in ascend- 

 ing order have been recognized by Gould: 

 Spring Creek clays, Greenlcaf sandstone, Kirby 

 clays, and Reeder sandstone. The names are 

 those proposed by Gould and Cragin and have 

 not been formally recognized by the United 

 States Geological Survey. These units are 

 cliiefly local phases or lentils in the Kiowa, of 

 little significance except as indicative of local 

 and more or less contemporaneous variations 

 in conditions of deposition, with perhaps a 

 basal member of the Dakota sandstone repre- 

 sented in the "Reeder." 



raSTORICAL SUMMARY. 



The term "Dakota group" was first used in 

 1861 by Meek and Hayden^ for the lower por- 

 tion of their section of the Cretaceous of Ne- 

 braska, corresponding to No. 1 of the classic 

 Meek and Hayden Upper Missouri section.^ 

 This term or simply Dakota or Dakota sand- 

 stone has subsequently been used in innumer- 

 able references to local geologic sections 

 throughout the West. The assumption that 

 the Upper Cretaceous of that whole region 

 contained two persistent sandstones — the Da- 

 kota at its bottom and the Fox Hills near its 

 top — and the fancied recognition of these 

 sandstones over a wide area have caused much 

 of the confusion and controversy that have 

 arisen over the interpretation of the western 

 Cretaceous. 



As originally understood the term Dakota 

 was applied to the pre-Benton Cretaceous, no 

 Lower Cretaceous being then recognized in 

 that region. Unquestionably the typical Da- 

 kota sandstone represents the littoral or mar- 

 ginal deposits of the transgressing Benton sea, 

 but that there are similar and somewhat 

 earlier continental or marginal sandstones in 



= Mcck, F. B., and Hayden, F. V., .\ca<l. Nat. Sd. Philadelphia 

 Proc, vol. 13, p. 419, IS61. 



silall, Jaraei, and Meek, F. B., .\m. .\cad. Mem., vol. 5, p. 405, 1856. 

 Meek, F. B., and Hayden, F. V., Acad Nat. Sci. Philadelphia Proc, 

 vol. 8, p. 63, 1856. 



19U 



