2o6 A. J. TIEJE 



below might be expected to exhibit signs of disturbance. They do 

 not. If the folding were due to change in volume in underlying 

 beds, "crinkled" strata ought to be fairly common. The Lykins 

 "crinkled" bed seems to stand almost alone. Without asserting 

 that the final word has been said, it may be suggested that limy 

 strata slipped, buckled, and brecciated upon a fairly steep sea slope 

 at a date when the foreland of early Lykins time was submerged. 



In upper Lykins time (Triassic ?),^ on the other hand, the climatic 

 pendulum was probably again swinging toward increased aridity, 

 hence the well-known but sporadic and discontinuous deposits of 

 gypsum, and the coarsening of the upper sandstones. Within the 

 last year, also, borings have penetrated salt beds near Eads in 

 southeastern Colorado. 



Interpretation: climate and paleo geography. — Climate has been 

 treated of, but it is interesting that what is known of Permo- 

 Carboniferous paleogeography bears out the upper-delta hypothesis. 

 Case, in an elaborate study of Permo- Carboniferous conditions, is 

 rather emphatic in tracing the marine limestone (W^reford) of south- 

 ern Kansas into the Red Beds (continental) of Oklahoma and thence 

 north to Nebraska and the Black Hills. There would seem, also, 

 to be a relationship between the Cimarron shales of Kansas and the 

 Lykins through the gypsiferous beds at Two Buttes (25 miles west 

 of the Kansas- Colorado line) and in the Purgatoire Valley (see 

 p. 204). Case remarks, finally, that the lower Red Beds of Permo- 

 Carboniferous age are in two areas of deposition, separated (see 

 his Plate IV) by a continuous land mass extending from Mexico 

 indefinitely northward, but at least uninterruptedly to far beyond 

 Colorado.^ The area of deposition involved in the present problem 

 Case defines as reaching from "north-central Texas to the Black 

 Hills and west to the Front Range of the Rocky Mountains."^ 

 _A11 this area "can only be considered," he writes, as "great flood 

 plains or deltas."'* 



' Whether or not the upper few hundred feet of the Lykins are Triassic, the writer 

 is not prepared to discuss. The evidence consists of a Belodon bone found by Darton 

 in the Purgatoire Valley. See also E. C. Case, "The Permo-Carboniferous Beds of 

 North America," Car. Inst. Pub. 207, p. 66. 



^ E. C. Case, op. oil., p. 88. 3 lUd., p. 71. " Ihid., p. 91. 



