ABSTRACTS OF PAPERS 85 



camp : first, because of the extraordinary richness and extent of the deposit ; 

 second, because of the depth of the ore shoot below the surface ; third, because 

 of very interesting geological conditions that are likely to throw considerable 

 liglit on the origin of these tellurides. At a depth of 1,265 feet a large cham- 

 ber was struck on November 25, 1914, the walls of wliich were heavily impreg- 

 nated with calaverite. The chamber was lined with a white porous material 

 that consisted mainly of celestite and that ran from $10,000 to $16,000 to the 

 ton. Evidences point to the chamber being part of a watercourse rising from 

 considerable depth. 



Presented in abstract extemporaneously. 



Discussion 



Dr. C. N. Fenner inquired whether there was not some similarity between 

 the general relations of the main ore-pipe at tlie Cresson mine as described by 

 Mr. Patton and those at the old Bassick mine in Custer County. In the latter 

 also there was a main ore-pipe of elliptical cross-section filled with a breccia, 

 whose pebbles were crusted with ore minerals. 



Messrs, Whitman Cross and H. B. Patton took part in the discussion. 



PLATINUM-OOLD LODE DEPOSIT IN SOUTHERN NEVADA 

 BY ADOLPH KNOPF 



(Abstract) 



The ore of the Boss gold mine in the Yellow Pine mining district, Nevada, 

 has recently been shown to contain considerable platinum. The deposit occu- 

 pies a vertical zone of fracturing in dolomite of Carboniferous age. The 

 gangue consists mainly of fine-grained quartz, but streaks of bismuth-bearing 

 plumbojarosite (a hydrous sulphate of lead and ferric iron) are found carry- 

 ing as high as 111 ounces gold, 99 ounces platinum, and 16 ounces palladium. 

 Some 600 feet from the mine is a small intrusion of granite porphyry, but no 

 basic intrusives occur ; in fact, none are known to occur in the whole district, 

 which is the most productive lead and zinc district in Nevada. 



Eead in full from manuscript. 



Eemarks were made by Prof. AV. H. Emmons. 



OROANIC ORIGIN OF SOME MINERAL DEPOSITS IN UNALTERED PALEOZOIC 



SEDIMENTS 



BY GILUEKT VAN INCiEN 



{Ahstnirl) 



The common association of galena, sphiilcritc, and some other minerals with 

 reef deposits of early I'alco/olc age was desci'ibed, and a suggestion was 

 otfert'd that the i-ecf-buildiiig organisms were directly responsible for tlu> pri- 

 mary concentration of these minerals, and that deposits of the Joplin, Mis- 



