The Schroff-O'Neil is a gold mine located in Alaska.
About the MRDS Data:
All mine locations were obtained from the USGS Mineral Resources Data System. The locations and other information in this database have not been verified for accuracy. It should be assumed that all mines are on private property.
Mine Info
Satelite View
MRDS mine locations are often very general, and in some cases are incorrect. Some mine remains have been covered or removed by modern industrial activity or by development of things like housing. The satellite view offers a quick glimpse as to whether the MRDS location corresponds to visible mine remains.
Schroff-O'Neil MRDS details
Site Name
Primary: Schroff-O'Neil
Secondary: Newman and Miller
Secondary: Miller-Newman
Commodity
Primary: Gold
Secondary: Zinc
Secondary: Lead
Secondary: Copper
Secondary: Tellurium
Location
State: Alaska
District: Willow Creek
Land Status
Not available
Holdings
Not available
Workings
Not available
Ownership
Not available
Production
Not available
Deposit
Record Type: Site
Operation Category: Past Producer
Operation Type: Unknown
Years of Production:
Organization:
Significant:
Physiography
Not available
Mineral Deposit Model
Model Name: Low-sulfide Au-quartz vein
Orebody
Not available
Structure
Not available
Alterations
Alteration Type: L
Alteration Text: Wall-rock alteration within a few inches of the veins is intense, but seldom extends more than 10 to 12 inches beyond the quartz filling. Sericitization and carbonate alteration predominate, but there is some pyritization and in the outer parts of the alteration zone chloritization is present (Ray, 1954).
Rocks
Not available
Analytical Data
Not available
Materials
Ore: Pyrite
Ore: Gold
Ore: Galena
Ore: Coloradoite
Ore: Chalcopyrite
Ore: Altaite
Ore: Tetrahedrite
Ore: Sphalerite
Ore: Nagyagite
Gangue: Quartz
Comments
Comment (Exploration): Status = Inactive
Comment (Geology): Age = Late Cretaceous or younger; vein cuts the Late Cretaceous Willow Creek Pluton.
Comment (Deposit): Other Comments = This mine apparently was originally referred to as the Newman and Miller prospect (Brooks, 1925).
Comment (Reference): Primary Reference = Ray, 1954
Comment (Workings): Workings / Exploration = Developed by 60 ft of open cuts in 1923 (Brooks, 1925). Most of the erosisional remnant was mined out by 1950 (Ray, 1954).
Comment (Deposit): Model Name = Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a)
Comment (Geology): Geologic Description = Mine located on an erosional remnant of a 1 to 6 inch thick quartz vein that cuts the Willow Creek Pluton. The coarsely crystalline quartz vein carries gold; the tellurides nagyagite, altaite, and coloradoite(?); galena in large cubes; pyrite; sphalerite; chalcopyrite; and tetrahedrite. The vein strikes N 70 E and dips 21 to 34 NW. The main vein is crossed by a barren copper-stained quartz vein. Ore deposition was apparently localized at the vein intersections. Nagyagite is an important mineral in that free gold shows a preference to it, especially in the richer ore. Some nagyagite and gold deposition appear to be contemporaneous (Ray, 1954).? the Willow Creek Pluton is a zoned pluton: the outer part consists of hornblende quartz diorite and lesser hornblende tonalite; the core consists of hornblende-biotite granodiorite, and lesser hornblende-biotite quartz monzodiorite and biotite quartz monzonite. Wall-rock alteration within a few inches of the veins is intense, but seldom extends more than 10 to 12 inches beyond the quartz filling. Sericitization and carbonate alteration predominate, but there is some pyritization and in the outer parts of the alteration zone chloritization is present (Ray, 1954).
References
Reference (Deposit): Brooks, A.H., 1925, Alaska's mineral resources and production, 1923: U.S. Geological Survey Bulletin 773, p. 3-52.
Reference (Deposit): Ray, R.G., 1954, Geology and ore deposits of the Willow Creek Mining district, Alaska: U.S. Geological Survey Bulletin 1004, 86 p.
Reference (Deposit): Cobb, E.H., 1972, Metallic mineral resources map of the Anchorage quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-409, 1 sheet, scale 1:250,000.
Reference (Deposit): Cobb, E.H., 1979, Summary of references to mineral occurrences (other than mineral fuels and construction materials in the Anchorage quadrangle, Alaska: U.S. Geological Survey Open-File Report 79-1095, 184 p.
Reference (Deposit): MacKevett, E.M., Jr., and Holloway, C.D., 1977, Map showing metalliferous mineral deposits in the western part of southern Alaska: U.S. Geological Survey Open-File Report 77-169-F, 38 p., 1 sheet, scale 1:1,000,000.
Reference (Deposit): MacKevett, E.M., Jr., and Holloway, C.D., 1977, Map showing metalliferous and selected non-metalliferous mineral deposits in the eastern part of southern Alaska: U.S. Geological Survey Open-File Report 77-169-A, 99 p., 1 sheet, scale 1:1,000,000.
Reference (Deposit): Chapin, Theodore, 1921, Lode developments in the Willow Creek district: U.S. Geological Survey Bulletin 714-E, p. 201-206.
The Top Ten Gold Producing States
These ten states contributed the most to the gold production that built the West from 1848 through the 1930s. The Top Ten Gold Producing States.
