246 E. C. CASE 



described as the Wichita conglomerate north of Seymour. Its 

 persistence and pecuHar character make it readily recognizable. 

 Just beyond Sagerton, southwest of Haskell, there is a steep bluff 

 of red clay and shales capped by a heavy sandstone just below which 

 is a thin layer of impure limestone with large-sized, irregular ripple 

 marks. A section taken on the east side of this bluff, locally known 

 as Flat Top, is as follows: 



Gray sandstone and fine reddish conglomerate 6-7 feet 



Impure limestone, gray, ripple marked 1-2 



Red clay with local harder layers and thin seams of gypsum .... 67 

 Shaly red clay and bluish clay 12 



In the lower beds are some nodules of gypsum and thin layers of 

 satin spar. 



These beds are evidently above the Clear Fork and are different 

 in color, in the regularity and persistence of the beds, and in the 

 first occurrence of gypsum in any quantity. Moreover, a careful 

 search failed to reveal any bones; not even fragments in the con- 

 glomerate. Cummins found fragments of bones on Paint Creek a 

 few miles southeast of Haskell. The country between Haskell 

 and the exposure just described is very flat or rolling, with a smooth 

 surface and few exposures of the rocks; there is no opportunity, 

 therefore, to determine the line of separation between the Clear 

 Fork and the Double Mountain and I doubt very much whether 

 such a line could be detected in the most favorable exposure. The 

 two series shade into each other so gradually that a sharp line of 

 demarkation does not exist. Double Mountain time was initiated 

 by a slow change in the sedimentation and the climate which 

 resulted in a more regular deposition and for short and irregular 

 periods in a great concentration of the waters. Either of these 

 changes would render the occurrence of vertebrate fossils in the 

 beds much less probable. West of Sagerton the surface of the 

 country is more irregular owing to the occasional breaking-down of 

 the capping layer of sandstone. This is especially true of the 

 breaks on the sides of the Double Mountain Fork of the Salt Fork of 

 the Brazos River. Just before the deeper part of the valley is 

 reached there are several layers of impure limestone which must be 

 considerably higher stratigraphically than the limestone seen at 



