GEOLOGY OF THE LARAMIE PLAINS 



Graphite occurs in the Laramie Hills. Among the western 

 foothills near Brush and Cottonwood creeks are quartz veins 

 which carry small quantities of gold, also magnetite and red 

 and brown garnets. At several points along the Laramie 

 Range the Upper Carboniferous is found resting directly on the 

 Archean. Tliis has been mentioned also by Hague. 



Arnold Hague's general section of the Jurassic and Cre- 

 taceous as published in "Geology of the 40th Parallel " is as 

 follows: 



Section southern part of Laramie plains, 

 Jurassic — 



1 . Friable white sandstone ] 



2. Reddish brown sandstone with thin layers of va- \ mnf t 



riegated clays and marls { 



3. Cream-colored sandstone and marls J 



4. Bluish gray cherty limestone [ 25 feet. 



5. Grayish white sandstone [ 75 feet. 



Triassic — 



6. Yellowish red sandstone 1 ^-jr. c 



7. Fine deep red sandstone j 



8. Argillaceous sand and shales with interstratified ) ten t 



u J f oo f . 1 50 feet, 



gypsum, one gypsum bed or ZZ leet J 



9. Red compact sandstone. [ 250 feet. 



1 0. Reddish gray sandstone. 



1 1 . Thin bed of gray cherty limestone. 



12. Coarse friable ash colored sandstone with pebble ) 0')'^ ( 



of angular chert and Archean fragments J 



The Como anticlinal consists of a steep mural face on the 

 north, sloping to the south, the main axis trending east and west. 

 Ridge bears north 60°; east dip 20° to 25°. Hague section 

 shows: 

 Jurassic — 



1. Compact yellowish brown sandstone, Dakota, 



with some conglomerate layers. 



2. Gray sandy marl. 



3. Cream colored marls with thin sandy layers. 



4. Bluish drab cherty limestone. 



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