346 



GEOLOGY OF TUB OENYEIl IJASIN. 



is given below. It comprises the entire series, and is as representative a 

 section as can lie obtained in a region showing so much variation in the 

 composition of its beds. 



DB 





-a 



Os/rea, 



tli of Mn 



.slmll N'„ 



■,1 of qu 



gnated 



i bed ut li 



■ half. 



luvors 



1 Sandsi ■ 11 1 solid forming top of bill t 



■' Sandstone white; shalj 



3. Sandstone; white; moderately coarse grains 



throughoui this report u^ "C" sandstone. 

 ■i. Workable coal bed "I" Marshall tfo. 5 mine. The outcrop of thit 



weathered as tt have the appearance of an extremely lignitic shale with a large 



portion of pure coarjj Layers threaded through it. It is possible thai the coal 



111111 belong .1 little lower down than this, 



5. Sandstone solid, bui incli 1 to shaly structure; slightlj Lignitic ofthequartz 



composition usual In the lower Laramie measures. 



6. Shale; lignitio; often verj brown, particular] 



7. Sandstone; white; fine-grained; quartzose; i 



uliirhtli ferruginous. Shades into 8. 



8. Sandstoue; one-grained; white; stained bro\ 



few bands of lignitic shale. 

 !i. Sandstone; white; quartzitic; resembles 14. 



10. Ostron bed; oonsists of calcareo-i 



n I mm 11 is in Ostrea; varies in thickness from 3 to 6 feet. Occasionally 1 mes n 



solid sandstone. 



11. Sandstone; white; fine-grained; contains a small amoui 'ablaok mineral with 



its black quartz. 



12. Coal; locally workable, bui not in the Marshal] field. Here it is of thenatureof 



lignitio Bbale. In ii« relation to sandstone B (No. U) it forms an excellent refer- 

 ence horizon 



13. Shale; lighi colored to white, with brown layers here and tliore. 



14. Sandstone; white; heavy-bedded; composed wholly of quartz; thickness vory 



persistent; designated in tlii* reporl as sandsi B. 



15. Shale; locally lignitio ; occasionally .1 coal, llways' present. 



18. Sandsi heavj bedded; white: thickness persistent; designated 



Sllllll- 



niti'l nil 



gray, yellow, 



us siinilsti.il. ■ A ; 11 anil if. (sandstone 

 stones .•!' tin- Laramie. 



I: iiimI A 1 are Kit 



• J. Oft 



1 tin' basal siinil- 



I'm 16 

 Laramie, M 



Section of coal 

 iwer .In. -ion of 

 iislmll district. 



Sandstone A is immediately underlain by the heavy lied of sandstone 

 which everywhere tonus the cap of the Fox Hills formation. At their line 

 of junction, bui in the lower sandstone, there is generally an abundance of 

 characteristic Fox Hills mollusks. 



In the locality affording this section there are two well-developed coal 



-cams, also several beds of lignitic shale, any one of which mighl he else- 



