THE WASATCH MOUNTAINS. 381 



THE WASATCH MOUNTAINS. 

 i>v 8. P. Emmons. 



The Wasatch Range, whose Imposing western front the party will 

 pass in review, is one of the most important single chains to the whole 

 Cordilleran system. Within its mass may be found representatives of 

 all the great geological formations recognized in the western United 

 States, and as a rule developed in greater thickness than the same hori- 

 zons show elsewhere in the system. Its topographical relations are also 

 somewhat interesting. All the waters drained from its slopes, whether 

 on the east or on the west, tiow finally into Great Salt Lake, which lies 

 at its western base, and these waters are practically the only feeders of 

 the lake. Thus the lake constitutes a great hydrometer, which meas- 

 ures the relation between the amount of water precipitated upon the 

 mountain range and that taken up by the dry desert winds which 

 sweep over its glassy surface. The general level of the lake surface is 

 about 4,200 feet, but the actual rocky bottom of the great valley in 

 Which it lies must be far deeper, for borings through the lake deposits, 

 which fill up the inequalities of its surface, have gone down 1,500 feet 

 in places without reaching the underlying rocks. The western or higher 

 crest of the range rises abruptly from 5,000 to nearly 8,000 feet (2130 m.) 

 above the present surface of the valley plains. 



Its present form, geologically considered, may be said to represent 

 only the eastern portion of the original range, the western half having 

 been sheared off and sunk below the valley level by a great fault, which 

 followed closely the line of its present western base. 



The internal geological structure of the Wasatch range is most compli- 

 cated, and the various dynamical movements by which it was produced, 

 if thoroughly and accurately worked out, would present an epitome of 

 the geological history of the greater part of the Cordilleran system. 

 The range was first systematically studied in 1809 by the geologists 

 of the exploration of the Fortieth parallel, and the preliminary deter- 

 mination of horizons thus made served as a basis for later determina- 

 tions throughout the whole breadth of the Cordilleran system. The 

 following table shows the general geological column of the Cordil- 

 leran system as a whole, as represented here. 



