CENTEAL AlfD EASTERN NEVADA. 339 



for a considerable distance along the ridge, are limestone-shales striking across 

 it in an easterly direction, with a southerly dip, forming almost a synclinal 

 with the limestones and shales in Smith's Canon. A boulder of the Point of 

 Rocks propylite was found in this canon, which may indicate that that body 

 extends under the ridge as far as this; as its origin was not discovered it can 

 be merely a matter of conjecture. 



From Smith's Canon, south to Washington Canon, extends a body of 

 limestone, forming the flanks of the main ridge, now a single crest, having a 

 strike parallel to its general direction, and resting on the slate series, which 

 are found, higher up in the canon, conformably stratified, while the crest of 

 the ridge is of white quartzite and granite, the former resting on the latter 

 and dipping westward. These limestones and slates form a high, rounded 

 hill, between Crane's and Washington Canons, inclosing a considerable inte- 

 rior basin, at the head of the latter, which was not visited. 



Beyond Washington Canon the limestones have changed in direction, hav- 

 ing an easterly strike and dipping to the northward, a change which, taken in 

 connection with the extension of the granite body to the west at the head of 

 San Juan Caiion, and the appearance of rhyolite at the mouth of this canon, 

 would seem to indicate a lateral fracture or fold at this point. 



In these limestones between Washington and Cottonwood Canons is the 

 New Hope Vein, which when visited showed only the croppings of a large 

 body of quartz, apparently striking north and south, carrying ores of silver, 

 combined with the yellow oxides of lead and blue carbonate of copper. This 

 was said to be very rich, yielding $800 to the ton. 



The white quartzite body forms the head of Cottonwood Canon, and the 

 high point of the main crest above it. At the head of San Juan Canon, how- 

 ever, the granite extends to the west side of the crest, succeeded, as else- 

 where, by the quartzites, and lower by the slates, on whose flanks comes the 

 rhyolite flow. This granite is noticeable on two accounts ; first, that asso- 

 ciated with large translucent crystals of orthoclase, it contains smaller crystals 

 of a feldspar, which, from the brilliant play of green and blue colors on the 

 cleavage facets, would seem to be a labradorite, though none of the crystals in 

 the specimens taken were sufficiently well defined to afford a satisfactory 

 crystallographical determination ; secondly, that its quartz is mostly in distinct 



