CENTRAL ROCKIES 



329 





SW MONTANA 



LIVINGSTON 



MT. LEIDY 



HOBACK BASIN 



EVANS TON 



COALVILLE 



STRAWBERRY 



WASATCH 

 PLATEAU 



SW UTAH 



PLEISTOCENE 



Glacial deps. 





7 



Glacial deps. 



Glacial deps. 













PLIOCENE 



Gravels on 

 intermed. surface 







Bivouac 

 Teewinot 



Camp Davis 



Huntsville 

 f angl. 







7 



Rhyolite flows 

 and pyroclaatics 



MIOCENE 



Medicine Lodge 

 Blacktail Deer Cr. 



Bozeman 

 Lake 



Colter 









Bishop cgl. 



Traychyte flows 



Page Ranch (vol3. ) 



OLIGOCENE 



Muddy Cr. 

 Cook Ranch 



beds 





Wiggins vol. 











Gray Gulch vols 



Quichapa (vols.) 

 Isom (vols. ) 



EOCENE 



Sage Creek 



1 



■7 



Aycross 

 Wind River 

 Indian Meadows 



Pass Pk cgl. 



Fowkes tuff 



Knight 



Fowkes tuff 

 Knight 



Park City vols. 

 Uinta 



Crazy Hollow 



•> 

 Green River 



Colton 



Needles Ra 

 Gray Clare 



n 



;e( voLs . ) 



e. 



PALEOCENE 



Beaverhead cgl. 





Pinyon cgl 



Hoback 



Almy 

 Evanston 





Current Cr. 



Flagstaff 



U. North Horn 



Red Clarori 



4 



DANIAN 



c 

 C 



o 



a 



•o 



Livingston 



Harebell cgl. 

 Meeteetse 





Adaville 





Ii 

 Mesaverde 



L. North Horn 



ICaiparowits 



MAESTRICHTIAN 



a > 



-H 

 C <D 



Eagle 



Lenticular 

 sequence 



7 





Echo Can. cgl. 



Price River cgl. 



Wahweap 



SENONIAN 



<0 > 



U H 





Coaly sequence 





Hilliard 



Wanship 



-; 



Blackhawk 



Strait Cliffs 







•o 

 a 

 c 







(H 

 O 



u 



TURONIAN 



.«- >> 



•H .O 

 T3 3 



C o! 



3 w 



Colorado 



Bacon Ridge 

 Cody 



Frontier 



Frontier 



Frontier 



Frontier 



Mancos 



Star Point 



Indianola 

 gr . ( cgl . ) 



Tropic 

 Dakot ,i 



to 



M 

 c c 



O -H 



u u 

 m a 



CENOMANIAN 



ALBIAN 



01 



3 

 



u o 

 4> u 



s a 



-U 



b 



O 



Aspen 





Mowry 



Aspen 

 Bear River 



Aspen 

 Bear River 



Aspen 

 Kelvin 



Mowry 







APTIAN 

 NEOCOMIAN 



Kootenai 





Thermopolis 

 Cloverly and 



Gannett 

 gr 



Gannett 

 gr. 



7 



Cedar 

 Mountain 



PORTLAND IAN 



Morrison 



Cloverly ? 



Morrison 





Morrison 



Morrison 





Morrison 



Morrison 



Fig. 22.2. Correlation of Cretaceous and Cenozoic formations along the east front of the Central Rockies. 



in Figs. 22.3 to 22.6 compiled in order to understand the situation bet- 

 ter. 



Although the standard time divisions need not have any bearing on 



I nature's orogenic phases in any particular region they seem to reflect 



the rhythms or cycles in the Central Rockies. Five main pulses of what are 



conventionally called compressional orogeny are indicated, namely, Early 



i Cretaceous, Colorado, Montana, Paleocene, and Eocene. The coarse and 



: thick clastic deposits and shifting sites of activity provide the basis for 



the recognition of the five main phases. After Eocene time volcanism 



and large-scale normal faulting were widespread and dominant (Fig. 



22.7). 



SOUTHWESTERN MONTANA 



Early Cretaceous Phase 



Ry reference to the paleotectonic maps of Chapter 3, it will be seen 

 that the Paleozoic formations thicken westward into the geosyncline from 

 about Dillon (see Fig. 22.3), and thin to shelf aspects eastward. As an 

 example the Pennsylvanian Quadrant sandstone is nearly 3000 feet thick 

 in the thrust sheet west of Lima, but a few miles to the northeast it is 

 only 400 to 500 feet thick. The shore line of the Triassic and Jurassic 

 formations lay approximately along the Idaho-Montana border west of 

 Lima, but a deep trough failed to develop immediately on the east of the 



