U. S. GEOLOGICAL SURVEY 



u 



GEOLOGIC AND TOPOGRAPHIC MAP 



OF THE 



RIO GRANDE ROUTE 



From Denver, Colorado, to Salt Lake City, Utah 



Compiled from United States Geological Survey atlas 

 sheets and reports, from railroad alinements and pro- 

 files supplied by the Denver & Rio Grande Western 

 Railroad Co., and from additional information col- 

 lected with the assistance of that company 



PREPARED UNDER THE DIRECTION OF 

 GEORGE OTIS SMITH, DIRECTOR 



EXPLANATION 



Great Ice Age 



Mountain glaciers as they were during the 



B hi^heat ataee and the 

 1 in its waters 



White shale and sandstone (Green River formation) 



Red shale, sandstone, and conslomerste 

 (Wasatch formation) 



Shale and aandstone (Mancos shale) 



Limestone and saDdstone 



Bright-red shale and sandstone 



Red sandstone and j (Park City fonnatioi 

 conglomerate i (Weberq --=--■ 



I {EoceTie) 

 Upper Cretaceous 



Triassic 



I Carboniferous 

 J- (1^7-mian and 

 j P^nnsylvanian) 





V Shale a 

 W Quartdte. schist, and slat« 



Y Lava flows 'andesite) 



_ Igneous intrusive rocks (g 

 *• and porphyry) 



Fault 



The geology of 



I I Miseigsippian > 

 ] Devonian 

 I Cambrian 



Cambrian 



Pre-Cambrian 



Tertiary 



1 about Salt Lake City is very complicated, and it has 

 i oeen mapped in detail except in the mining districts. The map here given 

 based largely on that of the Fortieth Parallel Survey, modified to fit. as well 



BULLETIN 707 SHEET No. 10 



Scale 500,000 

 Approximately 8 miles to 1 inch 

 ^ ^ ^ ^ 5 !0 Miles 



p 5 10 ISKilomet. 



