382 GEOLOGICAL EXCURSION TO THE ROCKY MOUNTAINS. 



Croup. 



Cenozoic 



Mesozoic 



System. 



Pleistocene ..'. 



Pliocene 5 



Miocene 5 



Eocene 



( hretaceous. 



.1 arassic 

 Triassio 



Paleozoic. 



Carboniferous 



Devonian 



Series. 



Where found. 



Bonneville Lake beds Qreal basin. 



Wyoming conglomerate Uinta mountains. 



Humboldt Cache valley. 



Traokee In Nevada- 

 White River K;ist of Rooky mountains. 



Bridgor Wasatoh and eastn ard. 



t; reen River Wanton and eastward. 



Wasatch (Vermillion Creek) . Waaatob. and eastward. 



Laramie Waaatob and *-;i si ward. 



Montana (FOX Hills) Wasatch and i ast ward. 



Colorado Wasatch and cast ward. 



Dakota : Waaatob and eastward. 



; Waaatob (tod eastward. 



Red beds Waaatob and eastward. 



l'cnno ( iarboniferous 



Upper Carboniferous 



Weber (grits and quartettes) . 



Lower Carboniferous 



Sub-Carboniferous 



Nevada (limestone) 



I J Ogilen (quartzite) 



Silurian ' Utel*oe;onil> (limestone) 



( 'amlirian . 



,. ,. , .i Huroiiian (Algonkiun). 

 Pre-Paleoxoio ! 



I Archean 



Middle Cambrian. 



Low it ( 'amhrian . 



Wasatch 

 Wasatch 

 Wasatch 

 Waaatob 



Wasatch 



Waaatob 



Wasatch 



Waaatob 



Wasatch 



Waaatob 



and e.ist ward. 



east and west, 

 east and west, 

 east and west, 

 cast and west. 



and westward. 



and west w ard. 

 east and west. 

 and west w ard. 



and w est w ard. 



Wasatch east and west. 

 Wasatch east and w est . 



While in the more recent phase of its geological history the range is 

 a great faulted block, the internal structure of that block proves the 

 existence of a succession of more ancient mountain ranges of compli- 

 cated structure produced by a succession of orographic movements at 

 different periods in the earth's history, of which only the most brief 

 and scanty outline can here be given. 



The following great transgressions or unconformities have been 

 observed, which mark critical epochs in its geological history : 



First. At the close of the Archean. 



Second. During Algonkiau or Pro-Cambrian times. 



Third. At the close of the Paleozoic. 



Fourth. Toward the end of the Jurassic. 



Fifth. At the close of the Mesozoic. 



Sixth. The final uplift in Tertiary times, which is continuing to the 

 present day. 



Of these movements the First, Third, and Fifth were the most wide- 

 spread, and have left, the most definite evidence of their existence, not 

 only here, but in other parts of the Oordilleran system. 



