SHAFTS AT CONTACT OF ODDIE BHYOLITE. 



MIRIAM SHAFT. 



193 



On the Miriam claim a shaft about -iO feet deep had been sunk at the time of 

 the writer's visit.. This shaft lies about 1,200 feet southeast of the Belle of Tonopah 

 and is at the contact of rhyolite and later andesite. It cuts at the top 30 feet of 

 brown decomposed later andesite and below this 10 feet of white rhyolite, which 

 is intrusive into the andesite. The rhyolite is typical and shows abundant quartz 

 and orthoclase phenocrysts with brown glassy groundmass. From some streaks 

 along this contact assays in gold were obtained, with no silver. 



DESERT QUEEN SHAFT. 



At a depth of 920 feet the Desert Queen shaft passed into the Oddie rhyolite, 

 the contact being flat. Twelve feet below this there was encountered a nearly flat 

 quartz vein, which is parallel with the rhyolite contact and consists of white or red 

 NE. sw. 



Surface 



Scale 



5 



10 feet 



FIG. 72. Vertical sketch section of shallow trench just north of Belmont shaft, showing contact of the Oddie rhyolite 

 intrusion with the later andesite. a=Oddie rhyolite; 6=later andesite. 



quartz carrying some pyrite. This quartz was 7 feet thick and had as a foot wall 

 the same body of rhyolite. The highest of several assays made showed 0.08 ounce 

 gold and 2.12 ounces silver, with a little galena and traces of arsenic and copper. 

 As this practically barren vein is within the Oddie rhyolite, it must be of later origin 

 than the rich veins in the earlier andesite. 



SHAFTS AT THE UNMINEHALJZED CONTACT OF THE OUDIE RHYOLITE. 



BELMONT SHAFT. 



The Belmont shaft (distinct from the Desert Queen shaft, which is also on 

 the Belmont property) is situated on the north side of Rushton Hill. At the 

 time of the writer's last visit, in July, 1903, the shaft was 340 feet deep, all in 



a For the description of the geology of the rest of the Desert Queen shaft, see p. 125. 

 16843 No. 4205 13 



