APPENDIX E. — GEOLOGY. 405 



corresponding to that of the elevating force, appears to be nearly 

 in the direction of north by west and south by east. From the 

 form of the lake and the different localities at which rocks of this 

 character occur, we may infer that there were two lines of eleva- 

 tion, corresponding with the divisions of the lake. 



The more elevated portions of the lake shore, and the mountain 

 ranges, consist of carboniferous limestone. In some localities this 

 limestone is partially altered, losing its granular character and 

 becoming sub-crystalline, or threaded by numerous veins of cal- 

 careous spar. In most localities, however, the limestone abounds 

 with fossils, particularly corals of the cyathophyllidese. 



From the records in the journal of observation and from speci- 

 mens, I have been able to indicate several localities of importance. 

 The principal of these is Stansbury's Island, the summit of which 

 is of limestone, and has an elevation of three thousand feet. The 

 limestone is said to rest on coarse sandstone and conglomerate, 

 specimens of which accompany the limestone. Limestone also 

 occurs on the mountains of the Spring Valley range, to the south- 

 west of the lake. 



Stansbury's Island, from its position at the southern extremity 

 of the lake, and from its isolated and elevated character, has been 

 more fully exposed than the localities on the west side. Along the 

 western shore, southward of Strong's Knob, the same limestone 

 was examined and noted in three places, and in two it is marked 

 as underlaid by sandstone. Limestone also occurs at Strong's 

 Knob with the altered rocks. West of the knob, another point is 

 indicated as limestone ; and northward of this, Gunnison's Island is 

 of the same rock. Dolphin Island, and also a considerable space 

 on the shore west of this island, are indicated as limestone, both 

 from specimens and the journal. On the eastern shore, opposite 

 Dolphin Island, limestone occurs in close proximity to metamor- 

 phic strata. 



It should not be omitted that the same limestone occurs to the 

 north of Great Salt Lake City, and is quarried in that neighbour- 

 hood. It appears both from the specimens and the notes of ob- 

 servation that the limestone overlies a coarse sandstone, or con- 

 glomerate, which almost invariably accompanies it. 



Although I have not felt at liberty to colour on the map any 

 other points than those indicated both by the notes and by specimens 

 examined, yet I can have no doubt but all the elevated ranges on 

 the west, south, and north of the Great Salt Lake are capped by 



