FRYER HILL. 257 



sheet of White Porphyry, and on the north slope of Carbonate Hill into the 

 Blue Limestone. This Gray Porphyry is exposed in the Vulture No. 2 

 workings of the Chrysolite mine, in the No. 5 shaft and drifts connecting it 

 with No. 1 of the New Discovery mine, and on Carbonate Hill in the lower 

 workings of the Waterloo and Henriett claims. The porphyry dike is seen 

 in the workings of the Chrysolite, Little Chief, Little Pittsburgh, Amie, Big 

 Pittsburgh, Hibernia, and Lee mines. The White Limestone has been 

 reached in the Amie No. 2 shaft, New Discovery No. 6, and found at the 

 surface under the Wash in the shafts of the Fairview, All Right, and Kit 

 Carson, and in the Chrysolite No. 6 (S-51), while the Lida shaft (S-52), 

 near Gumming & Finn's smelter, and the Little Eva (S 53) reach the 

 Lower Quartzite below the Wash, the former finding a small body of White 

 Porphyry included in it. 



PROSPECT MOUNTAIN. 



North of Evans gulch the geological structure, although probably more 

 simple, is more difficult to read, owing to the thickness of loose detrital mate- 

 rial above the rock surface and the relatively small amount of underground 

 exploration. The North Evans moraine covers an area, widening towards 

 its lower end, which but few miners have been enterprising enough to pen- 

 etrate to the rock surface beneath, while on Prospect Mountain itself the 

 Weber formations and the various porphyry bodies, of which it is mainly com- 

 posed, present but few definitely distinctive characters by which to guide 

 the geologist. In this region faulting action has apparently entirely ceased, 

 and the structure is that of a somewhat irregular system of anticlinal and 

 synclinal folds, whose axes run in such varying directions that it is difficult 

 to deduce from them a satisfactory system. Sections A and B, Atlas Sheets 

 XV and XVI, which run east and west, and Sections M and N, Atlas Sheet 

 XXII, which run north and south, give a graphic delineation of the system 

 of folds at right angles to either. 



crest of the ridge. To the north and east the White Porphyry gradually 

 thins out and the Gray Porphyry comes in contact with the Blue Lime- 

 stone, while above this a sheet of Mount Zion Porphyry rapidly thickens 

 and reaches its maximum on the north side of the Prospect Mountain, facing 



MON XII 17 



