PEOQUOP AND TOANO PASSES. 501 



between 6 and 7 miles in width, composed of the Lower Quaternary fine 

 clays and silts which characterize the Great Desert. In the dry season, 

 over the greater part of this area, is found a heavy incrustation of quite 

 pure common salt, derived from the beds below, which are evidently 

 strongly impregnated, if, indeed, they do not carry a stratum of chloride 

 of sodium. If necessary, there is no doubt but that this formation could 

 be made to yield immense quantities of salt. From Pilot Peak, numerous 

 streams run down beneath the debris of the slopes, coming to the surface 

 near the plain in large springs. Many of them are quite fresh, but others, 

 where the waters percolate through the Lower Quaternary strata before 

 reaching the surface, are either brackish or highly charged with salt. At 

 the Ombe Gap, north of the mountains, through which the railroad runs, 

 occur alkaline deposits, consisting of an admixture of chloride of sodium 

 and sulphate of soda. 



Peoquop and Toano Passes. — Directly north of the Little Cedar 

 Mountains, Peoquop and Gosi-Ute Ranges, and on a line nearly due east 

 from the termination of the East Humboldt Archaean mass, occurs an inter- 

 esting break in the structure of the Palaeozoic strata. The Carboniferous 

 quartzites and limestones which form these narrow meridional uplifts are 

 here thrown abruptly into a northeast and southwest direction, accompanied 

 by considerable displacement, causing marked depressions and physical 

 breaks in all three ranges, which may be easily recognized by reference to 

 the geological maps. The railroad company have taken advantage of these 

 gaps in constructing their line from the Salt Lake Basin to the headwaters 

 of the Humboldt River. At Cedar Pass, the beds are much disturbed ; at 

 Peoquop Pass, the continuity of strata is broken, and a deep basin lying 

 between the Peoquop Range and the Fountain Head Hills is occupied by 

 Eocene Tertiary deposits; while, north of Toano Pass, the Carboniferous 

 strata strike almost directly across the trend of the Gosi-Ute Range. 



The Tertiary deposits which occupy Peoquop Pass extend in an east 

 and west line for a distance of 8 miles, and rest unconformably upon the 

 steep flanks of both sides of the gap. They strike northeast and southwest, 

 and dip both to the north and south at angles varying from 6° to 15°. 

 The railroad-cuts and stream-beds expose a series of fine carbonaceous 



