. Transactions. he New York. Throughout thewhole distance, it is attended with fissuring. At the NewYork there is a belt of the limey shale, with possibly a fissureddike which the vein follows, being always parallel to the fissur- QUARTZ-VEINS OF SILVER PEAK, NEVADA. 651 ing. The quartz outcrop is very prominent for 500 ft. overthe New York hill, and extends some distance beyond. Thebelt of foreign rock (limey shale, etc.), included in the granite,is about 100 ft. wide, but is local; another inclusion joins it onthe north, more evidently the limey shale country-rock; here,both the shale and gr
. Transactions. he New York. Throughout thewhole distance, it is attended with fissuring. At the NewYork there is a belt of the limey shale, with possibly a fissureddike which the vein follows, being always parallel to the fissur- QUARTZ-VEINS OF SILVER PEAK, NEVADA. 651 ing. The quartz outcrop is very prominent for 500 ft. overthe New York hill, and extends some distance beyond. Thebelt of foreign rock (limey shale, etc.), included in the granite,is about 100 ft. wide, but is local; another inclusion joins it onthe north, more evidently the limey shale country-rock; here,both the shale and granite are sheared, but more nearly northand south than at the vein, and with some silicification. Along-side the vein the granite is not sheared on the New York(as it is further south),—as if there had been enough of theshale to take up the movement. There are, perhaps, three ages of greenstone dikes,—a dioritequite recent, running NW-SE.; a greenstone later than the HIGHEST POINTSTOPED ONCROWNING GLORY VEIN. BRUNTON1 SHAFT 46 19Vein inTunnel Fiw. 1.—Projected Cross-Section of Crowning Glory andDrinkwater Veins. veins and sometimes faulting them, and a greenstone olderthan the veins, which, to a great extent, the latter have followed. Mr. Spurr thinks that all the dikes are later than the veins;but those followed by the veins sometimes enclose them, andthe quartz is not sheared or broken, while the dike, especiallythat portion occupied by the vein, is sheared to quartz, both in the dikes and granite, is usually remark-ably clean. Distinct silicification of the dikes is seen, which,however, might be secondary. The Sentinel mine is on the divide between the New Yorkand the Drinkwater, in the limey shale. The only ore-body andoccurrence of quartz of consequence is at the open cut alongside 652 QUARTZ-VEINS OF SILVER PEAK, NEVADA. the road. This lens is about 30 ft. long, 20 ft. at the widest,strikes K 20° W., and dips from 20° to 25° E., conformablywith th
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