WICHITA FORMATION OF NORTHERN TEXAS 119 



Wichita River and Beaver Creek in the line of their strike north- 

 ward. Greater difficulty is encountered in the effort to trace the 

 lower beds of the "Albany," owing to the greater proportions of 

 clays and sands and the disturbed condition of sedimentation, both 

 conditions becoming more pronounced as the beds are followed 

 northward. Certain of the limestone beds, however, are persistent, 

 although showing changes in their physical character, and by means 

 of these the eastern boundary of the formation was ascertained 

 with a fair degree of accuracy. At Fane Mountain, a low eleva- 

 tion in the southeastern corner of Throckmorton County, is an 

 outcropping of limestone characterized by an abundance of Myalina 

 permiana. These beds occur at intervals northward in eastern 

 Throckmorton County, and at Spring Creek in the northwestern 

 corner of Young County they outcrop in the bank of the river about 

 a mile from the post-office. Here the beds show locally a gradation 

 into sandstone suggesting near-shore conditions of sedimentation. 

 On Godwin's Creek, in the western part of Archer County, the 

 diminished representatives of these, or possibly somewhat higher, 

 beds appear, as also farther north on the Big Wichita River. The 

 limestone which outcrops on the Big Wichita north of Fulda, 

 referred to on p. 116, is evidently one of the lowermost beds. The 

 most northerly appearance of presumably the equivalents of these 

 beds was noted in the vicinity of Electra in the western part of 

 Wichita County, where occasional plates of limestone appear over 

 the surface apparently as a result of the weathering out of lenses 

 of limestone in the clays. In the case of the Cisco formation the 

 changes which these undergo toward the North have not had care- 

 ful study. The limestone, however, appears to thin out entirely 

 in the northern part of Young County, there being no representa- 

 tives of these formations in the "Red Beds" area except it be the 

 impure, calcareous nodular beds described above. 



Nowhere in the southern area so far as observed are there any 

 indications of unconformity. Notwithstanding the lithological and 

 faunal characteristics which distinguish the "Albany," these beds 

 appear perfectly conformable with the Cisco below and the Clear 

 Fork above, nor is there within the formation any indication of 

 stratigraphic discordance. The change in the lithological character 



