GEOLOGY OF THE LARAMIE PLAINS 



Soapstone and sandstone between all the coals. 



Below to 1 , 1 80 feet all sandstone. The record shows an 

 extraordinary development o[ coal strata, sixteen beds of 

 coal aggregating 48 feet. Some of this coal I saw last summer 

 in coal bins at Medicine Bow station and it certainly is a 

 beautiful and pure looking coal. 



Lesquereux considers the Laramie of carbon to be Miocene 

 at Evanston; Upper Eocene at Raton, and Golden, Lower 

 Eocene. The vegetation he considers Oligocene; at Black Butte 

 and Rock Springs, Lower Eocene; at Point of Rocks, Rock 

 Creek and Evanston, Upper Eocene and Lower Miocene form 

 the flora. 



These coals are often termed lignitic. Some even have 

 over I 2 per cent of water in their composition, which would 

 show a relation to the English brown coals. The percentage of 

 ash is low, being from 2 to 6 per cent. Marvin, in Hayden's 

 report for 1873, speaks of this, and also of their remarkable 

 purity. Iron pyrites occur in exceedingly small quantity. A 

 mineral resin is sometimes found. The following analyses are 

 from Hayden's report, 1873: 



Sp. Grav. 



1.38 



1.33 



1.31 

 1.34 

 1.29 

 1.23 



Fix. Carb. 



47 



49 to 51 



50 



46 to 50 



54 



52 



Cooper, Wyo . 

 Carbon 



v. P. 



Bl. Butte 

 Pt. of Rocks 

 Rork 



Springs 



Much more could be said descriptive of the various coals 

 but the above is probably sufficient. 



G. C. BROADHEAD, 



Columbia, Mo. 



Ash 



4.5 



6 to 8 



3.22 



3 to 8 



1.73 



9.55 



Locality 



47 — 



