WICHITA FORMATION OF NORTHERN TEXAS 117 



subdivided them into five divisions as follows: Richland, Milburn, 

 Brownwood, Waldrip, and Coleman. Later the Milburn was 

 included in the Brownwood. 1 The relations of these rocks as now 

 recognized are as follows : 2 



The beds dip to the west at a low inclination estimated by 

 Cummins to be 30 feet per mile for the "Albany" and 75 for the 

 Canyon. 



Limestones constitute the dominant characteristics of the 

 "Albany" and Canyon formations, while sandy shales and sand- 

 stones, with some conglomerates, make up the larger part of the 

 Strawn and Cisco formations. It is with the two uppermost of 

 these, the "Albany" and Cisco, that the "Red Beds" problem is 

 concerned. 



The "Albany." — The "Albany," named from the county seat of 

 Shackelford County, consists of blue, gray, and yellowish lime- 

 stones, alternating with beds of blue and dark-gray shales. The 

 upper 500 feet are characterized by massive beds of hard blue 

 limestone, with partings of blue shale, while the lower portion 

 shows a greater development of shale, the limestone being for the 

 most part thin-bedded and shaly. The heavy ledges of limestone 

 appear at the surface in a succession of terraces which extend in 

 sinuous curves from north to south. Sandstones and conglomerates 

 are almost entirely lacking. The formation contains an abundant 

 marine fauna, which, taken in connection with the notable devel- 

 opment of limestones, indicates deep seas and quiet conditions of 

 deposition. Above, the formation grades rather abruptly into red 

 gypsiferous clays and red sandy shales and sandstones. The base of 



1 R. T. Hill, Twenty-first Annual Report of the U.S. Geological Survey, Part VII 

 (1899, 1900), 98. 



2 The thicknesses cited are those given by Drake, "Report of the Colorado Coal 

 Field of Texas," Fourth Annual Report, Texas Geological Survey (1892), 371-446. 



