100 



WESTEEN 



To see the structure of the Wasatch Mountains, the traveler should 

 make a side trip to the local scenic attraction, Ogden Canyon, which 



can he reached hy street car from Ogden station. In 



Ogden Canyon. 



bright atternoon sunlight it can easily be seen tnat 

 the face of the range is divided into hands of different 



rock formations. 



XX\ 



itself is a mass of pink rock called quartzite. 



Observation Peak 

 5 rock was a wide- 



of sand which was laid down on the bottom of the sea 

 time the earliest forms of hfe appeared on the earth. 



ame 



footnote. A dark band 

 ber, lies below the peak. 



brush 



iwn 



which m 



similar tc 

 formation 



This pink 



) 



being due to breaking of the earth's crust and pilin< 

 ments. In fact the structure of tlie mountains at Og 

 that of the cakes of ice in an ice jam. 



the repetition 



to thousands of feet, \\lien the rocks on 

 one side are shoved up over those on the 

 other side. The break is called a re- 

 verse or overthrust fault. (See fig. 12.) 



period of slow earth movement which 

 made these mountains flat-lying paralle' 

 beds of rock were locally turned on edge, 

 crumpled, and folded in a wonderfully 



xm 



a b 



FiGUKE 12.— Diagram showing normal faults (a) and a reverse or overtlirust fault (b). 



In tlie region now occupied by the intricate manner. These upturned and 



crumpled rocks are well exposed in Ogden 

 Canyon. The west face of the Wasatch 

 Range is believed to mark the plane of a 

 normal fault (fig. 12) at a nearly vertical 



cloee 



the broken pieces of the earth's crust be- 

 tween them were pushed up, the rocks on 



Cambrian 



Carbonirenous 



A!gonXlan 



Arch 



FiGTiRE 13.— Biagramtaatic stracture secti 



one side of e-ach crack riding up over 

 tliose on the other aide until a great moun- 



f 



range 



plain. 



Range 



IKC 



companying diagram (fig. 

 le etructiire of the Wasatch 

 section. During the long 



crack in the earth's crust, the rocka on 

 the east aide of which went np or those 

 on the west side went down. The forces 

 which have raised these mountains are 

 still active, for movement along this 

 ^ult has disturbed the surface recently. 



