432 GEOLOGY OF NORTHWESTERN TEXAS. 



distance to the westward without break or change for hundreds of miles, ex- 

 cept here and there where some stream has cut its way through, forming a 

 deep, narrow chasm a mile or less in width, with perpendicular walls on both 

 sides, often to the depth of the entire formation. 



In No. 6 of this formation I found the fossil remains of a small turtle 

 about six inches across and fragments of a large mammal. 



1 made the following section about one mile south of Mount Blanco. Be- 

 ginning at the bottom: 



1. Reddish clay 30 feet. 



2. Red clay 2 feet. 



3. Sandy greenish clay 30 feet. 



4. Chalk 8 feet. 



5. Packsand 20 feet. 



6. Chalk 4 feet. 



1. White sandy clay . 30 feet. 



8. White calcareous sandstone 4 feet. 



9. Stalactitic limestone 4 feet. 



10. Sandstone 3 feet. 



1 1. Limestone, hard 2 feet. 



12. Soil 8 feet. 



Total 145 feet. 



The reddish clay (No. 1) of the above section looks very much like it had 

 been deposited in a fresh water lake. In the packsand (No. 5) of the section 

 are remains of large mammals. I found the tooth of a fossil horse. There 

 is not much uniformity in any of the beds at this place except that of the 

 reddish clay and the stalactitic limestone, which everywhere form the base 

 and top of the Plains. 



The following section was made one-fourth of a mile northwest of H. C. 

 Smith's house and one mile north of Mount Blanco: 



1. Red clay (same as No. 1 of previous section) 130 feet. 



2. Stalactitic limestone 10 feet. 



3. Limestone 2 feet. 



Total 142 feet. 



North of this there is no chalk along the canyon, but the stalactitic lime- 

 stone lies directly upon the heavy beds of red clay. At the base of this 

 formation there is a bed of sand that furnishes an abundance of water. About 

 four miles above Mount Blanco there are two large springs that come up 

 from this sand and give a large amount of water at all times. Wherever 

 wells have been put down to this sand on the plains an abundant supply of 

 good water has been obtained. Along the canyon below Mount Blanco at 

 various places large springs are found. A fine flow comes from a spring on 

 Crawfish Creek, about one mile south of Mount Blanco. In the vicinity of 



