190 FORMATION WEST OF THE LAKE — FIELD OF SALT. 



crossed it, and attempted also to cross the cliannel whicli separated 

 it from the main shore, when we were driven back by the depth 

 of the water. 



After a hearty breakfast on fresh beef-bone soup, which the 

 poor fellows from the region of " Tophet" enjoyed exceedingly, 

 they were despatched after the rest of their company, with direc- 

 tions to join me at once, in order to survey the island upon which 

 we were at present encamped. They were in rather a deplorable 

 condition ; their coffee being exhausted — their flour almost gone — 

 and theii' stock of water reduced to a single five-gallon keg. 



The rest of the day was spent in erecting a station upon the 

 highest peaks of the island, and in unloading the yawl upon a plat- 

 form placed upon kegs and barrels set up in the water, preparatory 

 to hauling her up, she having become so leaky, from thumping on 

 the rocks and being dragged over sand-bars, as to endanger the 

 safety of the provisions. The gnats here were perfectly intolera- 

 ble, and drove us almost mad. 



The character of the country passed over by the line of survey 

 during my absence was much the same as that which had prevail- 

 ed more to the northward ; viz. extended plains, with grease-wood 

 and sage. Water, there was none ; and our sole dependence was 

 now upon the supply to be furnished by the boat from the eastern 

 side of the lake. 



The detritus from the mountains, whenever encountered, con- 

 sisted principally of compact sandstone, abundance of calcareous 

 tufa, coarse sandstone, and conglomerate. From the report of 

 Mr. Carrington, of a partial examination made by him of the range 

 west of Dolphin Island, it consists of calcareous tufa and conglo- 

 merate, overlying which was argillaceous limestone of various 

 colours and texture, extending to the base of the short spurs of the 

 ridges ; above this was found black, bluish, and gray limestone, 

 very compact and fine grained, veined with calc spar ; above this 

 again, was an inferior or earthy limestone, overlaid by a brownish- 

 gray fossiliferous limestone, capped by an argillaceous limestone, 

 which extended to the summit of the range. The vegetation was 

 the ever-recurring artemisia, bunch-grass, and a few scattering 

 dwarf cedars not more than ten feet high. 



On the flats near the lake, and immediately west of the island, 

 a large field of solid salt occurred, beautifully crystallized upon 

 the sand, about half an inch thick ; and the crystals, from one to 

 two inches in diameter, glittered in the bright sunshine like a bed 



