DIAMOND -^lOl'NTAIXS. 27 



stones of the Upper I)evi>iii:ui foriu the reiiiainihT of the steep shtpe for 

 ;i1)out 1,000 feet and tlien stretch far out into the valley in a line of low 

 hills and isolatecl huttes, still dipping toward the east. The entire western 

 side of the mountain, iiu-ludin<^- the summit of the ridge, dips uniformly 

 toward the west, and is in tui-u overlain hy the White Pine shales through 

 Avhicli Hayes C'an\dn has been eroded. < )n the nortli side of Newark 

 Mountain these flexible shales curve around to the northeast and form tlie 

 east base of Diamond I'eak, only the uppermost beds of the Nevada lime- 

 stone here appearing alioxc tlie level of the valley, the remaining portion 

 of the Devonian beds upon l»oth sides of the fold having dropped completely 

 out of sight. 



Diamond Peak rises al)ove Newark Valley over 4,000 feet, with an 

 excei^tionally steep slope, tlie White Pine shales pre.senting smooth rounded 

 ridges along the base of tlie mountain. The shales are overlain by a great 

 thickness of rough and rugged Diamond Peak quartzites, followed ])v the 

 Lower Coal-measure limestones which for a- long distance form the summit 

 of the ridge. In its structure the Diamond Range is in strong contrast with 

 tlie anticlinal sti-ucttu'e of Newark Mountain, presenting a synclinal fold 

 whose axis lies in the Lower Coal-measures. The identical series of beds 

 found dipping into tlie pt-ak on the east side come in again on the west 

 side, but with a res'erse dip, except that the White Pine shales are not 

 brought to the surface, owing to a longitudinal fault which extends along 

 the west side of Diamond Peak, completely cutting them off ami bringing 

 up still higher Carboniferous formations than those found near the summit. 

 From the axis of the anticline on the east slope of Newark Mountain diag- 

 onally across Diamond Peak there is exposed an admirable section, includ- 

 ing Nevada limestones, White Pine shales, Diamond Peak quartzites, and 

 Lower Coal-metusure limestones. The geological importance of this section 

 lies in the fact that it offers, across the middle of the Paleozoic rocks, a con- 

 formable anil continuous series of beds rarely found elsewhere, imiting the 

 upper Paleozoic with the great development of Silurian and Cambrian rocks 

 beneath. From Bold lUutf, at the southern end of Diamond Peak, the New- 

 ark fault brings the I^ower Coal-measures against the White Pine shales, the 

 entire develoj)ment of Diamond Peak quartzite having been displaced ah^ng 



