CHAPTER VI. 



AGE OF THE RED BEDS. 



The age of the Red Beds north of Oklahoma, in Kansas, was long in 

 doubt, due to the absence of fossils. At first considered as Carboniferous, 

 or Permian, by the earliest writers, they were later referred to the Cretaceous, 

 and finally to the Triassic and Upper Permian. The history of the various 

 discussions of the age of these beds has been summarized by Cragin "* and 

 Prosser,'' and need not be reviewed here. The final conclusion of those who 

 have worked latest upon the Kansas beds is that they are of the same age as 

 the Texas-Oklahoma beds, i. e., Permian or Pcrmo-Carboniferous. This con- 

 clusion has been reached because of the more or less complete tracing of the 

 beds into Oklahoma and even Texas, and the finding of Permo-Carbonifer- 

 ous fossils in the Red Beds of Kansas. 



With regard to the Texas Red Beds the opinion is less consistent. Cope, 

 and, following him, later writers, considered the vertebrate fauna as indicating 

 the Permian age of the beds. Case," in 1908, reported on the fossils found in 

 Upper Pennsylvanian beds of Pennsylvania, and this led him to a recon- 

 sideration of the value of the evidence of the vertebrate fauna of Texas for 

 the Permian age of the Red Beds. His results were purely negative,'' but a 

 single genus common to America and Europe being restricted to the Permian 

 of Europe. Later he discovered Spirifer rockymontana above beds carrying 

 Permo-Carboniferous vertebrates in New Mexico. This is a Pennsylvanian 

 form not occurring above that horizon (Schuchert) and perhaps limited to 

 the Allegheny (Girty, letter to the author). These facts have led Williston 

 and Case " to the conclusion that the vertebrate beds of Texas, Oklahoma, 

 and New Mexico are to be considered on the border-line between the Permian 

 and Carboniferous. 



Taff ^ places the Permian {sic) of Texas above the Cisco. "This group 

 (the Albany) is succeeded by the Permian, which overlaps upon the Cisco 

 division between the Brazos and the Red River." 



Udden*^ says the Wichita "rests on the Cisco." And again, page 31: 

 "Evidently the geographic conditions prevailing during the deposition of the 

 Wichita beds were different from those existing during the making of the 

 Cisco." 



" Cragin, Colorado College Studies, vol. VI, pp. 2 and 396. 



'' Prosscr, Kansas University Geological Survey, vol. II, pp. 55 and 97, 1897. 



" Case, Ann. Carnegie Mus., vol. iv, Nos. 3 and 4, pp. 23 and 41. 



■1 Case, Jour. Geol., vol. 16, No. 6, pp. 572-580, 1908. 



" Williston and Case, Jour. Geol., vol. xx, No. i, pp. 1-12, 1912. 



' Taff, 22 Ann. Rpt. U. S. Geological Survey, part 3, p. 402, 1902. 



s Udden, Bull. University of Texas No. 246, p. 1, 1912. 



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