GRAYS PEAK. 133 



obliquely, with approximately the same strike as the strata on South Hill. 

 In this southern extension the only fossils obtained were ChaeMes and as- 

 sociated corals so abundant in the Lower Nevada limestone. 



Grays Peak. This name has been given to the flat topped summit which 

 forms the eastern limit of the broad quartzite plateau. It offers a command- 

 ing 1 view, as the country falls off rapidly to the south and east. On the 

 summit the beds lie nearly horizontal, but break away abruptly and dip 

 off iu every direction accompanied by mural-like escarpments produced by 

 a series of small parallel faults lying wholly within the quartzite. On the 

 eastern side the slope descends for nearly 1,000 feet, with an average dip 

 of 20, the angle of the slope and the inclination of the beds coinciding 

 within 1 or 2. South and east the quartzites are overlain by the Nevada 

 limestones which dip away from the peak with varying angles. On the east 

 side the line of contact between the two formations is strongly marked by 

 a deeply eroded ravine draining into Grays Canyon. While these lime- 

 stones have been referred to the Nevada period, it is by no means definitely 

 ascertained that beds which in other places have been assigned to the Lone 

 Mountain series may not here, in some instances, rest upon the quartzite. 

 In many instances there is an entire absence of bedding, and in others the 

 strata rest unconformably upon the quartzite. Apparently the underlying 

 limestones belong to the transition series between well recognized Silurian 

 and Devonian, but pass rapidly into limestone which has everywhere else 

 in the district been assigned to the Nevada epoch. These limestones stretch 

 away to the south in insignificant monotonous hills and ridges of lower 

 Devonian age and have as yet yielded only a few obscure corals of wide 

 vertical range. North of Grays Peak on the plateau where the beds lie 

 either horizontally or at low angles, there are several patches of limestone 

 still left in place as remnants of erosion. These exposures resemble the 

 beds of the Lone Mountain series and serve to show by their geological 

 position that the quartzites on the ridge belong to the upper members of 

 the Eureka epoch. To the westward of these Silurian limestone patches 

 the quartzites break down in abrupt walls and cliffs toward Lamoureux 

 Canyon much in the same way as seen on the east side of Grays Peak. 

 Along Lamoureux Canyon, however, the wall is most persistent, continuing 



