406 GEOLOGY OF NORTHWESTERN TEXAS. 



before reaching the river there is a line of sand hills running parallel with 

 the river. They are simply sand dunes caused by the drifting sands from 

 the surrounding level country. 



The hills in the vicinity of the Double Mountain Pork are composed of 

 red clay and a thin seam of impure bluish limestone. The clays are a lighter 

 red than those farther east. The following section was made three and one- 

 fourth miles southeast of Kiowa Peak and below the junction of the Double 

 Mountain Fork and the Salt Fork of the Brazos River: 



section no. 14. 



1. Red clay, with seams of fibrous gypsum 40 feet. 



2. Greenish gypsiferous sandstones , . . . 10 feet. 



3. Blue clay, with thin seam of copper 4 feet. 



4. "White cross-bedded sandstone, with worm borings 12 feet. 



5. Conglomerate, in thin seams at top, and slanting back to top of hill 20 feet. 



Total 86 feet. 



At this place we have the beginning of the great gypsum fields that extend 

 to near the foot of the Staked Plains. The waters are all impregnated with 

 salts and are not palatable. 



The following section was made at the copper mine about one mile south 

 of Kiowa Peak: 



section no. 15. 



1. Gypsum and sandstone, thin bedded 10 feet. 



2. Red clay 20 feet. 



3. Blue clay, with copper 4 feet. 



4. White thin-bedded sandstone 3 feet. 



Total .' 37 feet. 



The base of this section is about two hundred feet above the top of the 

 previous section. The entire distance is a succession of sandstones and gyp- 

 sum, with only one thin bed of impure limestone. 



The copper clay mentioned in the above section is the upper copper bear- 

 ing bed in the Permian in the State, and is found in several places north of 

 this locality. The bed at the smelter west of Benjamin, in Knox County, is 

 at the same geological horizon, as is also the bed of copper on Raggedy 

 Creek, in Hardeman County. The country west of Kiowa Peak is very 

 rough, the hills high, and the gulches very deep. 



The following section was made at Kiowa Peak: 



