90 



TE 



Just before entering Morgan tlie train passes close to the foot of a 

 slope on the right (north) in which dark-colored limestone containing 

 fossil corals and shells of early Carboniferous Olississippian) age is 

 well exposed. Farther west rocks of Ordovician and Cambrian age 

 are exposed north of the track, but these can not be readily distin- 

 guished from the train. 



The soft Tertiary rocks that occupy the basin west of Morgan may 

 be seen to the right from the train, north of Peterson, where they 

 appear as light-green to pink strata, slightly conglomeratic and in- 

 clined toward the east. 



The station at Peterson is near the center of the basin just described. 

 The basm was formerly occupied by a bay of the ancient Lake Bonne- 



Peterson. 



Elevation 4,892 feet. 

 Population 277.* 

 Omaha 983 miles. 



ville, whose waters backed up throudi Web 



yon 



(See pp. 97-99.) Along the margin of this bay, 



more 



accumulated ii 

 withdrew from 

 heK, remnants 



Wh 



accumulations 



railroad at many places on the slopes. 



Alany a ^'station" along the Union Pacific Raiboad consists of 



more than a signpo 



Strawberry. 



Elevation 4,S42 feet. 

 Omaha 9S5 miles. 



Vis 



sidetrackino; cars to e; 



maj 



railroad, and which furnish gravel for ballast. From 



m 



views 



which 



& 



Wasatch Range.^ 



prominent mountain north of the railroad. 

 ^s the main mass of the southern nart of the 



The Wasatch is the easternmost of the 



I* 



basin ranges. Although 



:ribed 



earth ^s crust 



western 



that it inclines eastward, 

 made possible by a break 



tilting 



base 



along what 



The rocks 



fracture 



tha 



lug- 



producing a great fault. Later the ele- 

 vated part of the block was eroded, so that 

 now ita surface is a compUcated mass of 

 nigged mountains, separated from one an^ 

 other by valleys, canyons, and mr^^ 



The western face of the range which was 

 originally nearly straight and might have 

 been a single cliff had it not been eroded, 

 is still ver>' precipitous and forms what is 

 known as a great fault scarp. It is this 

 western fault scarp that is so impressive 

 as seen from Ogden and other points in 

 the valley of Great Salt Lake. 



The Uinta Mountains differ from the 

 Wasatch Mountains in that they have re- 

 sulted from the erosion of a broad arch 



axis 



asatch 



The Uinta is 



the westernmost of the Eocky Mountain 

 ranges, which reach their maximum de- 

 velopment farther east in central Colo- 

 rado. The junction of this range with the 



