List of Earth MRI focus areas with mineral system = Reduced intrusion-related

Reduced intrusion-related

Reduced intrusion-related systems form in continental magmatic arcs by similar processes from fluids exsolved from calc-alkaline plutons and stocks that assimilated carbonaceous pyritic country rocks. Resulting ore deposits tend to be poor in Cu, Mo, Sn and enriched in W, Au, Ag, Te, Bi, Sb and As.

Color on map:

Deposit types

Name	Commodities	Critical minerals
Pegmatite LCT	Li-Cs-Ta	Li, Cs, Ta, Nb, Sn, Be, Cs
Gold	Au, Ag	Te, Bi, Sb, As
Greisen-V tungsten	W, Mo	W, Mo
Skarn copper-molybdenum-tungsten	W, Mo, Cu, Au, Ag	W, Te, Bi, Re
Polymetallic sulfide S-R-V-IS	Au, Ag, Pb, Zn, Cu	Mn, Ge, Ga, In, Bi, Sb, As
Distal disseminated silver-gold	Ag, Au	Te, Bi, Sb, As
Intermediate sulfidation	Au, Ag, Pb, Zn, Cu	Mn, Ge, Ga, In, Bi, Sb, As
Intermediate sulfidation antimony	Sb	Sb
Graphite	Graphite (lump)	Graphite (lump)

References

Hart, C.J.R., 2007, Reduced intrusion-related gold systems, in Goodfellow, W.D., ed., Mineral deposits of Canada--A synthesis of principal deposit types, district metallogeny, the evolution of geological provinces, and exploration methods: Geological Association of Canada, Mineral Deposits Division, Special Publication 5, p. 95-112.
Nutt, C.J., and Hofstra, A.H., 2007, Bald Mountain gold mining district, Nevada--A Jurassic reduced intrusion-related gold system: Economic Geology, v. 102, no. 6, p. 1129-1155. [Also available at https://doi.org/10.2113/gsecongeo.102.6.1129.]
Luque, F.J., Huizenga, J.M., Crespo-Feo, E., Wada, H., Ortega, L., and Barrenechea, J.F., 2014, Vein graphite deposits--Geological settings, origin, and economic significance: Mineralium Deposita, v. 49, no. 2, p. 261-277. [Also available at https://doi.org/10.1007/s00126-013-0489-9.]
Wang, Z., Li, M.Y.H., Liu, Z.R.R., and Zhou, M.F., 2021, Scandium--Ore deposits, the pivotal role of magmatic enrichment and future exploration: Ore Geology Reviews, v. 128, article no. 103906, accessed April 12, 2021, at https://doi.org/10.1016/j.oregeorev.2020.103906.

Source: Hofstra, A.H., and Kreiner, D.C., 2020, Systems-Deposits-Commodities-Critical Minerals Table for the Earth Mapping Resources Initiative: U.S. Geological Survey Open-File Report 2020-1042, 24 p., https://doi.org/10.3133/ofr20201042.

Focus area	Region	States	Mineral Systems	Deposit types	Commodities
Alaska Peninsula-Aleutian Range Gold	Alaska	Alaska	Reduced intrusion-related	Gold	gold; silver
Central Alaska-Seward Peninsula Gold	Alaska	Alaska	Reduced intrusion-related	Gold	gold; silver
Chugach Range Gold	Alaska	Alaska	Reduced intrusion-related	Gold	gold; silver
Eastern Alaska Range-Talkeetna Mountains Gold	Alaska	Alaska	Reduced intrusion-related	Gold	gold; silver
Eastern Brooks Range-Old Crow Gold	Alaska	Alaska	Reduced intrusion-related	Gold	gold; silver
Kuskokwim Mountains Gold	Alaska	Alaska	Reduced intrusion-related	Gold	gold; silver
Western Alaska Range Gold	Alaska	Alaska	Reduced intrusion-related	Gold	gold; silver
Yukon-Tanana Upland Gold	Alaska	Alaska	Reduced intrusion-related	Gold; Skarn copper-molybdenum-tungsten	copper; gold; molybdenum; silver
Shawangunk Mountains Area	Northeast	New York	Reduced intrusion-related	Polymetallic sulfide S-R-V-IS	copper; gold; lead; silver
Big Iron	Northwest	Washington	Reduced intrusion-related	Skarn copper-molybdenum-tungsten	copper; gold; iron; molybdenum; silver
Latah County beryllium	Northwest	Idaho	Reduced intrusion-related	Pegmatite LCT	(none)
Orogrande Mining District	Northwest	Idaho	Reduced intrusion-related	Skarn copper-molybdenum-tungsten	copper; gold; molybdenum; silver
Bald Mountain mineral district	Southwest	Nevada	Reduced intrusion-related	Skarn copper-molybdenum-tungsten	copper; gold; molybdenum; silver
Buffalo Canyon	Southwest	Nevada	Reduced intrusion-related	Gold; Greisen-V tungsten	gold; molybdenum; silver