600 



UNITED STATES MINERAL RESOURCES 



pyrite, smithsonite, and chalcocite ores are not gen- 

 erally so analyzed. Silver-rich sphalerite is mined 

 in southeast Missouri and in the Nigadoo mine in 

 the Bathurst district of New Brunswick ; silver-rich 

 chalcocite is mined at White Pine, Mich., and is com- 

 mon in the sandstone chalcocite ores of Connecticut 

 and near Walton, Nova Scotia. Silver-rich pyrite was 

 thrown on the dumps of the Milan massive sulfide 

 mine in New Hampshire; silver-rich smithsonite 

 ores were found in several districts in Colorado, 

 Utah, Nevada, and California, but the silver was 

 seldom recovered because the silver content was not 

 recognized. Analyses for silver should be made in 

 these and in many other common minerals from the 

 waste material in old mining districts as well as in 

 all new discoveries. 



Minerals bearing silver, such as the manganese 

 oxides, or chlorides, iodides, and bromides, have been 

 automatically classed as supergene minerals wher- 

 ever found. Hewett (1968) has shown that hypo- 

 gene silver-manganese oxide minerals are common 

 at one locality, and they have been identified else- 

 where in the West (Hildebrand, 1967). Cerargyrite, 

 embolite, and other silver halides theoretically could 

 be deposited as hypogene minerals as well as super- 

 gene ; these minerals are notably difficult to identify. 

 They might occur in closed lake basins where chlo- 

 ride brines are present to precipitate silver from sil- 

 ver-bearing hot-spring solutions, such as those found 

 at the edge of the Salton Sea in southern California. 



As the lead-zinc industry becomes increasingly 

 dependent on eastern low-cost silver-lean lead and 

 zinc, silver production will probably depend increas- 

 ingly on copper-silver deposits of the several types 

 and upon silver-rich ores in which silver is the main 

 product. With the gap increasing between silver 

 production and consumption, another search for epi- 

 thermal silver deposits is probably warranted, using 

 the newly developed geochemical and geophysical 

 prospecting techniques. 



The recovery of more bjT)roducts will help sup- 

 port production of marginal ores. Valuable elements 

 now wasted, such as manganese, bismuth, germani- 

 um, tellurium, and tin, as well as silver might 

 be recovered by new and better metallurgical 

 techniques. 



SELECTED REFERENCES 



Ageton, R. W., 1970, Silver, in Mineral facts and problems: 



U.S. Bur. Mines Bull. 650, p. 723-737. 

 Anderson, C. A., 1969, Massive sulfide deposits and vol- 



canism: Econ. Geology, v. 64, no. 2, p. 129-146. 

 Anderson, C. A., and Creasey, S. C., 1958, Geology and ore 



deposits of the Jerome area, Yavapai County, Arizona: 



U.S. Geol. Survey Prof. Paper 308, 185 p. 



Anderson, E. C, 1957, The metal resources of New Mexico 

 and their economic features through 1954: New Mexico 

 Bur. Mines and Mineral Resources Bull. 39, 183 p. 



Bachau, Christian, 1971, Essai de typologie quantitative des 

 gisements de plomb et de zinc avec la repartition de 

 I'argent: Bur. Recherche de Geol. et Mineralogie, thesis, 

 Univ. de Lausanne, Faculte des Sci. 116 p. 



Banistu, D'Arcy, and Knostman, R. W., 1969, Silver in the 

 United States: U.S. Bur. Mines Inf. Circ. 8427. 



Barnes, M. P., and Simos, J. G., 1968, Ore deposits of the 

 Park City district with a contribution on the Mayflower 

 lode, in Ridge, J. D., ed.. Ore deposits of the United 

 States 1933-1967, Graton-Sales Volume, v. 2: Am. Inst. 

 Mining, Metall., and Petroleum Engineers, p. 1102-1126. 



Bastin, E. S., 1922, Bonanza ores of the Comstock lode, 

 Virginia City, Nevada: U.S. Geol. Survey Bull. 735, p. 

 41-63. 



Bateman, A.M., and McLaughlin, D. H., 1932, Geology of the 

 ore deposits of Kennecobt, Alaska: Econ. Geology, v. 27, 

 no. 2, p. 291-306. 



Becker, G. F., 1882, Geology of the Comstock lode and 

 Washoe district: U.S. Geol, Survey Mon. 3, 422 p. 



Bischoff, J. L., and Manheim, F. T., 1969, Economic jtotential 

 of the Red Sea heavy metal deposits, in Degens, E. T., 

 and Ross, D. A., eds.. Hot brines and recent heavy metal 

 deposits in the Red Sea: New York, Springer- Verlag, 

 p. 535-541. 



Boutwell, J. M., 1933, Excursion 4, Park City mining dis- 

 trict: Intemat. Geol. Cong. Guidebook 17, p. 69-81. 



Boyle, R. W., 1963, The geochemistry of silver and its de- 

 posits: Canada Geol. Survey Bull. 160. 



1972, The geology, geochemistry, and origin of the 



barite, manganese, and lead-zinc-copper-silver deposits 

 of the Walton-Cheverie area, Nova Scotia: Canada Geol. 

 Survey Bull. 166, 181 p. 



Bradbury, J. C, 1961, Mineralogy and the question of zoning, 

 northwestern Illinois zinc-lead district: Econ. Geology, 

 V. 56, no. 1, p. 132-148. 



Brown, J. S., 1970, Mississippi Valley type lead-zinc ores: 

 Mineralium deposita, v. 5, p. 103-119. 



Burbank, W. S., and Luedke, R. G., 1968, Geology and ore 

 deposits of the western San Juan Mountains, Colorado, 

 in Ridge, J. D., ed.. Ore deposits of the United States 

 1933-1967, Graton Sales Volume, v. 1 : Am. Inst. Mining, 

 Metall., and Petroleum Engineers, p. 714-733. 



Butler, B. S., 1913, Geology and ore deposits of the San 

 Francisco and adjacent districts, Utah: U.S. Geol. Sur- 

 vey Prof. Paper 80, 212 p. 



Cannon, R. S., Jr., Pierce, A. P., Antweiler, J. C, and Buck, 

 K. L., 1961, The data of lead isotope geology related to 

 problems of ore genesis: Econ. Geology, v. 56, no. 1, p. 

 1-38. 



Clark, L. D., and Miller, F. K., 1968, Preliminary geologic 

 map of the Chewelah Mountain quadrangle, Stevens 

 County, Washington : Washington Div. Mines and 

 Geology, Geol. Map GM-5. 



Cox, M. W., 1968, Van Stone mine area (lead-zinc) , Stevens 

 County, Washington, in Ridge, J. E., ed., Ore deposits 

 of the United States 1933-1967, Graton-Sales Volume, 

 V. 2: Am. Inst. Mining, Metall., and Petroleum Engi- 

 neers, p. 1511-1519. 



Creasey, S. C, and Granger, A. E., 1953, Geologic map of 

 the Lake Valley manganese district, Sierra County, New 



