lO THE PERMO-CARBONIPEROUS RED BEDS OF 



corner of Haskell County and thence southward, he says that it is the type 

 area of the Wichita formation: 



"The western part of this area is characterized by the occurrence of beds of 

 limestone and blue shale interbedded with red clays and sandstones, while the 

 eastern part is notable for the entire absence of limestones and the very limited 

 development of blue shale and clay. If a line be drawn from a point where the 

 Salt Fork of the Brazos crosses the boundary between Throckmorton and Young 

 Counties, a little east of north to the Red River, it will mark approximately the 

 boundary between the areas thus lithologically distinguished. * * *" (Page 112.) 



"Rocks of the Wichita Area. — East of Baylor County the rocks consist for the 

 most part of red concretionary clays, red sandstones and sandy shales with occa- 

 sional beds of blue shales, and bluish to grayish-white sandstones. Limestones are 

 conspicuously absent. Occasional impure nodular layers occur, however, which con- 

 tain considerable calcareous matter, but these do not constitute strata of limestone. 

 The sandstones are usually soft and distinctly cross-bedded. In some places they are 

 shaly, in others massive. Some layers are streaked and specked with grains of 

 black iron oxide, while others contain nodular masses and concretions of iron ore. 



' ' The clays are mostly deep red or red mottled with bluish-white and drab 

 colors. The red clays contain an abundance of nodular concretions of irregular 

 shape, varying in size from that of a pea to masses 4 or 5 inches in diameter. They 

 consist of clay, iron, and lime, and are at times hollow or with the interior filled 

 with calcareous clay or lime carbonate. In some cases they are flattened and stand 

 in vertical position in the clays, suggesting their origin through the filling of fissures. 



' ' Occasionally a bed is met with consisting of rounded lumps of hardened clay 

 cemented together by ferruginous matter, representing what Cummins called a 

 'peculiar conglomerate.' This formation is believed to have had its origin in the 

 breaking-up of a bed of clay by running water or wave action. 



"In places the bluish clays are copper-bearing. Efforts to mine these deposits 

 have not been profitable. The ore occurs in the form of small nodules in the clays 

 and also as a replacement of wood. 



"In the sandstones occasional traces of plants occur, and sometimes remains 

 capable of identification are found. White reports Taniopteris from the sandstones 

 near Fulda. The stratification of the beds is very irregular. The sandstones, 

 shales, and clays grade into each other both vertically and horizontally. More- 

 over, there is a monotonous similarity in the sandstones and shales respectively 

 throughout the area, which, taken in connection with the absence of any persistent, 

 easily recognizable stratum, renders the stratigraphic correlation of the beds, except 

 within very narrow limits, practically impossible. In eastern Clay and Montague 

 Counties, the beds, considered Cisco, show a greater development of sandstones, 

 some of which are conglomeratic. In the western part of the area, however, no 

 true conglomerates were observed. * * * 



"In the bluffs of the Wichita River, in the northwestern comer of Wichita 

 County, some beds of limestone, aggregating 4 feet in thickness, appear at the top 

 of the escarpment on the west side of Horseshoe Lake, and outcrops of these appear 

 at intervals along the boundary of Archer and Baylor Counties. The limestone 

 is earthy, very hard, dark blue where fresh, and weathers to dark brown or black. 

 It is underlain by 4 feet of blue clay. The remainder of the section to the foot of 

 the hill, about 100 feet, consists of red, concretion-bearing clay, with a limited 

 development of red and white shaly sandstone. From this point west the strati- 

 fication becomes more regular, consisting of the blue shales alternating with red, 



