|Current site name||Hansen Creek Deposit|
|Alternate or previous names||satellite deposit of Getchell Gold Mines|
|Related records||10310336, 10310488|
|Geographic coordinates:||-117.25874, 41.20989 (WGS84)|
|Relative position||The Getchell Mine is located in Potosi Mining District, about 45 miles (70 kilometers) northeast of Winnemucca, Nevada. Access to the property is by paved road from the main Interstate Highway, I-80.|
|(click for info)|
|Mount Diablo||038N||042E||04, 09||Nevada|
|Mount Diablo||039N||42E||28, 29, 32, 33||Nevada|
|Materials||Type of material|
|USGS model code||26a.1|
|Deposit model name||Sediment-hosted Au|
|Mark3 model number||17|
|Host or associated||Host|
|Rock type||Sedimentary Rock > Clastic Sedimentary Rock > Shale|
|Rock unit name||Preble Formation|
|Host or associated||Host|
|Rock type||Sedimentary Rock > Carbonate > Limestone|
|Rock type qualifier||silty|
|Rock unit name||Preble Formation|
|Host or associated||Associated|
|Rock type||Plutonic Rock > Granitoid > Granodiorite|
|Rock unit name||Osgood Mountains pluton|
|Local||Gold mineralization is generally found at the intersection of a number of high-angle and low-angle fault sets. The low-angle faults and associated folds are the result of Devonian and Permian-age compressional events and the higher angle faults and fracture sets formed during Tertiary extension. Mineralization is both structurally and stratigraphically controlled. The Getchell fault is a zone of overlapping fractures which have an overall strike of N10W. Hotz and Willden (1964) offer evidence for up to 3500 feet of left lateral strike slip displacement and only a relatively small amount of dip slip movement along the Getchell fault. McCollum and McCollum (1991) indicate that the sense of movement on the Getchell fault is right lateral.|
|Regional||thrust faults to the north and NNW-trending faults.|
|General form||Individual orebodies are roughly tabular|
|Commodity type||Both metallic and non-metallic|
|Discoverer||Edward Knight and Emmet Chase|
|Year of first production||1938|
|Year of last production||1999|
|Production years||1938-1945; 1948-1950; 1962-1967; 1985-1999|
|District name||Potosi District|
|District name||Getchell District|
|Ownership category||BLM Administrative Area|
|Area name||Winnemucca BLM Administrative District|
|Owner||Placer Dome Gold|
|Owner||Newmont Gold Mining Company|
McCollum, L. B. and McCollum, M., 1991, Paleozoic rocks of the Osgood Mountains, Nevada, in Raines, G. L., et al, eds., Geology and Ore Deposits of the Great Basin, The Geological Society of Nevada, Reno, p. 735-738.
Bagby, W. C. and Cline, J. S., 1991, Constraints on the pressure of formation of the Getchell gold deposit, Humboldt County, Nevada, as interpreted from secondary-fluid-inclusion data, in Raines, G. L., et al, eds., Geology and Ore Deposits of the Great Basin, The Geological Society of Nevada, Reno, p. 793-804.
Madden-McGuire, D. J., 1991, Stratigraphy of the limestone-bearing part of the lower Cambrian to lower Ordovician Preble Formation near its type locality, Humboldt County, North Central Nevada, in Raines, G. L., et al, eds., Geology and Ore Deposits of the Great Basin, The Geological Society of Nevada, Reno, p. 875-893.
Berger, B. R. and Tingley, J. V., 1985, History of discovery, mining, exploration of the Getchell mine, Humboldt County, Nevada, in Hollister, V. F., ed., Discoveries of epithermal precious metal deposits, case histories of mineral discoveries vol. 1, Society of Mining Engineers, New York, P. 49-51.
Berger, B. R., 1985 Geological and geochemical relationships at the Getchell Mine and vicinity, Humboldt County, Nevada, in Hollister, V. F., ed., Discoveries of epithermal precious metal deposits, case histories of mineral discoveries vol. 1, Society of Mining Engineers, New York, p. 51-59.
Dunning, Gail E., 1988, calcium arsenate minerals new to the Getchell Mine, Nevada, The Mineralogical Record, Vol. 19, No. 4, p. 253-257.
Erickson, R. L., Marranzino, A. P., Oda-Uteana, and Janes, W. W., 1964, Geochemical exploration near the Getchell Mine, Humboldt County, Nevada, USGS Bulletin 1198-A, 26 pp.
Hardy, R. A., 1940 Geology of the Getchell Mine, AIME Technical Publication No. 1240, 3 Pp.
Wise, F. and Wark, C. W., 1940, Metallurgy and milling practice at Getchell Mine, AIME Technical Publication 1260, 9 Pp.
First Mississippi Corp., Annual Reports for fiscal years 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991.
NBMG, 1994, MI-1993
Nevada Division of Minerals, 1994
Long, K.R., DeYoung, J.H., Jr., and Ludington, S.D., 1998, Database of significant deposits of gold, silver, copper, lead, and zinc in the United States; Part A, Database description and analysis; part B, Digital database: U.S. Geological Survey Open-File Report 98-206, 33 p., one 3.5 inch diskette.
Placer Dome Gold Company website, 2003
|Subject category||Comment text|
|Deposit||The known gold deposits within the Getchell Trend are Carlin- type, sediment-hosted, replacement deposits containing micron gold. Gold mineralization is found in a number of different rock types generally at the intersection of a number of high-angle and low-angle fault sets. The low-angle faults and associated folds are the result of Devonian and Permian-age compressional events and the higher angle faults and fracture sets formed during Tertiary extension. Mineralization is both structurally and stratigraphically controlled. Gold is associated with arsenic, mercury, and to a lesser extent antimony, and commonly with pervasive decalcification, silicification and carbonaceous alteration. Gold is micron-scale generally intergrown with arsenical pyrite, which in turn, is encrusted in barren, diagenetic pyrite. Late stage realgar and orpiment are commonly associated with high-grade ores. The main deposit is confined to a zone nearly 7000 ft. long at the northern end of the Getchell fault zone. Deep exploration shows that the mineralization persists at least 1 km down-dip on the Getchell fault system and also occurs along the parallel Village fault. Maximum width of ore is 200 ft., with an average width of 40 ft. Within ore zones, gold occurs as native grains that range in size from <1 micron to nearly 1 mm, with smaller grains more abundant than larger grains. Most of the gold is intimately associated with the fine grained quartz-carbon matrix of the altered rock termed "gumbo" by Joralemon (1951). Of the sulfides, pyrite and marcasite are principal hosts to gold. As of 1951, the gold:silver ratio in bullion ranged from 2:1 to 134:1 and averaged 10:1 for the entire bullion production to that date. Joralemon (1951) observed microscopic metallic grains in the Getchell ore that he concluded were native silver, although the particles were so small that conclusive chemical tests were not possible. No other silver minerals have been recognized except for very rare grains of electrum. Geochemical work at the Getchell mine and vicinity has demonstrated that As-W-Hg anomalies occur in rocks and soils over the arsenic-gold deposits and that these anomalies are not broad haloes but are restricted to the mineralized area. The highest metal contents are found in oxidized iron-rich material along fractures and bedding planes in barren bedrock, lesser values in caliche coatings on exposed bedrock, and lowest but still anomalous values in soil.|
|Reporter||01-JUN-2005||LaPointe, D.D.||Nevada Bureau of Mines and Geology|
|Editor||01-SEP-2007||Schruben, Paul G.||U.S. Geological Survey||Converted from S&A FileMaker format to Oracle. Edit checks on rocks, units, and ages with Geolex search, and other fields.|