ABSENCE OF WHITE PINE SHALE. 145 



desert region of Hayes Valley out into Diamond Vallev. On the south 

 side of The Gate the beds strike N. 20° W., dipping- 20° easterly, but on 

 the north side they strike X. 55° W., with a dip increased to 30° easterly. 

 Owing to tlie tiu-ust wliich forced the beds toward the east the walls on the 

 south side l)elong mainly to the Diamond Peak quartzite, while those on the 

 north side are formed of a bold cliff of Nevada limestone. The sections 

 across the strata on opposite sides of the gorge are readily correlated by 

 structural features confirmed by i)aleontological evidence. Fortunately, 

 just beneath the Diamond Peak beds south of The Gate a fauna character- 

 istic of the Upper Nevada limestone occurs in the low ridge near the west 

 entrance to the pass. There is exposed here a thickness of 1,000 feet of 

 the upper limestones. The underlying beds ai'e dark gray in color, with 

 poorly pi'eserved fossils, followed b}- a black baud bearing many large 

 Sfromatopora and other corals. Interstratified in these limestones are several 

 quite shaly beds, seldom more than 1 foot in thickness. These gray beds 

 are followed by a belt of distinctly stratified black limestones, weathering 

 a light color, and yielding numerous corals. Above this, again, are thinly 

 bedded, dense limestones, extending up to the overlying quartzites. In 

 these latter beds occur the Upper Devonian fauna already mentioned. 

 Conformably overlying the limestones occurs a broad belt of Diamond 

 Peak beds, forming the wall along the south side of The Gate and extend- 

 ing in low, round, monotonous hills out to Diamond Valley. The cliffs on 

 the north side of The Gate expose about 500 feet of massive, dark lime- 

 stones, passing into shaly and fissile beds 2 or 3 feet in thickness. A rich 

 and varied fauna from this locality will be found published in full on 

 page 83. The locality would well re])ay a more diligent and careful 

 search. 



Absence of White Pine Shale.— On both sides of the gorgc the overlyiug 

 siliceous beds are much the same, the base of the series being made up of 

 quartzites, iuterbedded, impure sandstones, compact, dense argillites, fine 

 conglomerates, and black sherty layers, rapidly passing into purer quartz- 

 ites. On the south side the black cherty belts present a greater thickness 

 and are not confined to the base of the horizon. 



It will be noticed that no mention has been made of the White Pine 

 MON XX 10 



