emmons] GEOLOGICAL PANORAMA OF THE WASATCH RANGE. 387 



daikcr limestone above, ean be readily distinguished at the very crest, 

 while the lower part of its steep western face is formed of darker struc- 

 tureless Archean rocks. 



At a re-entering angle of the mountain front, just south of the Hot 

 Springs, known as Ogden's Hole, is a transverse fault at right angles 

 to the trend of the range, whose .movement has been a downthrow on 

 the south, by which movement the Cambrian and Silurian are brought 

 down to the foot of the steep western face of the mountains, while Lower 

 Carboniferous limestones form the crest of the ridge. 



Directly east of Ogden city is Ogden canyon, a narrow gorge cutting 

 entirely across the range, and connecting with a small interior valley, 

 once a bay of Lake Bonneville, which affords an admirable exposure of 

 the whole series of rocks from the Archean up to and through the Lower 

 Carboniferous. 



,7 ust south of Ogden canyon a smaller ravine marks the line of an- 

 other transverse fault, with upthrow to the south, by whose movement 

 the Archean rocks on the south are brought nearly to the crest of the 

 range, with a thin covering of Cambrian quartzite which disappears to 

 the south. 



A few miles south of Ogden is the still deeper gorge cut by Weber 

 river which drains a large portion of the eastern slopes of the Wasatch. 

 The Rio Grande Western railroad passes round a delta of the Bonne- 

 ville Lake beds that in great measure hides this fine gorge. The gorge 

 affords an admirable section from Archean up to Cretaceous and un- 

 conformable Tertiary beds, which can be seen along the line of the 

 Union Pacific railway as it crosses the mountains. 



Prom Weber canyon southward for nearly 20 miles (32 km.) the crest 

 and west front of the range is of Archean rocks; while coarse Tertiary 

 conglomerates rest high up on the eastern Hanks and conceal all the 

 lower beds. At the southern end of this Archean mass the older sedi- 

 mentary beds appear again, through denudation of the conglomerates, 

 striking nearly cast and west, and dipping southeast and south away 

 from the Archean. These upturned beds, broken through by erupt i\ e 

 locks and partly covered by Tertiary beds, jut out to the westward of 

 the main front of the range, forming a projecting promontory between 

 the Mormon town of Oenterville (east of Lake Shore station) and Salt 



Lake city. 



This promontory is formed of steeply upturned Paleozoic beds, partly 

 covered by a coarse conglomerate of supposed Tertiary age and an 

 eruptive body of trachyte or andesite. The Warm Springs at the 

 point of the promontory issue from the much broken Paleozoic lime- 

 stones. The canyon of City creek, directly north of Salt Lake city, 

 cuts through the conglomerate and eruptive body, and near its head, 



