210 COAL FIELDS OF THE COLORADO RIVER. 



Feet. In. 



1. Soil 6 



2. Limestone 6 



3. Red clay 9 



4. Sandstone 2 10 



5. Clay with, ironstone concretions 5 



6. Fossiliferous lime shale 2 



1. Blue shale 12 



8. Hard limestone (compact) 8 



9. Red clay shale 22 



10. White sandy shale 18 



11. Blue clay rock 12 



12. Coal (very irregular, sometimes a pure shale) 6 



13. Clay parting (variable) 3-10 



14. Coal ., 6-8 



15. Clay parting 3-4 



16. Coal (quite uniform) 8 



11. Fireclay 2 



Note. — The clay partings are sharply separated from the coal, so that in mining the coal is obtained free from 

 clay. The two lower seams of coal are chiefly depended upon, and they are easily mined. 



Quite uniformly covering the Waldrip coal division, and generally not 

 more than one hundred feet above the coal, is a layer of limestone, the lowest 

 member of a series of alternating limestones, clays, shales, and sandstones 

 which I shall call the Coleman division, on account of their splendid devel- 

 opment in Coleman County and near the town of Coleman, the county seat. 

 The thickness of this lower limestone is quite variable, being more than 100 

 feet west of Trickham; but west of the Silver Moon coal mine, near the Jim 

 Ned, it does not exceed 25 feet. 



In order to show the general character of the beds of the Coleman series 

 the following section is given, from the upper beds of the Waldrip coal 

 series, four miles southeast of Santa Anna, in a northwest direction, through 

 the town of Coleman to the Cretaceous, eight miles northwest of Coleman. 

 The construction of a section in a region so largely composed of soft clays, 

 which by their ready disintegration hide the strata beneath, is a difficult 

 task. It is impossible to make a direct section, and I have been obliged to 

 interpolate largely from one side or the other of my general section line. 



Feet. 



1 . Compact limestone 20 



2. Sandstone , 50 



3. Rusty limestone 25 



4. Sandy shale 10 



5. Pulverulent limestone ....... 3 



6. Mottled clays 25 



1. White limestone 50 



8. Sandstone, changing to sand limestone below. ...*,* . * ,<.,.,. ^ ..,.,, , .,,,»*. 12 



