The Difficult Creek is a zinc, copper, and 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
Difficult Creek MRDS details
Site Name
Primary: Difficult Creek
Commodity
Primary: Zinc
Primary: Copper
Primary: Gold
Location
State: Alaska
District: Reboubt
Land Status
Not available
Holdings
Not available
Workings
Not available
Ownership
Not available
Production
Not available
Deposit
Record Type: Site
Operation Category: Occurrence
Operation Type: Unknown
Years of Production:
Organization:
Significant:
Physiography
Not available
Mineral Deposit Model
Model Name: Massive sulfide, kuroko
Orebody
Not available
Structure
Not available
Alterations
Alteration Type: L
Alteration Text: The Difficult Creek occurrence has alteration characteristics of a Kuroko type massive sulfide deposit that includes sulfate alteration, and silification.
Rocks
Not available
Analytical Data
Not available
Materials
Ore: Sphalerite
Ore: Pyrite
Ore: Gold
Ore: Chalcopyrite
Gangue: Quartz
Gangue: Calcite
Gangue: Barite
Gangue: Anhydrite
Comments
Comment (Geology): Age = Jurassic massive sulfide.
Comment (Exploration): Status = Inactive
Comment (Deposit): Model Name = Kuroko massive sulfide (Cox and Singer, 1986; model 28a)
Comment (Deposit): Other Comments = This occurrence is owned by Cook Region Native Association.
Comment (Geology): Geologic Description = The Difficult Creek occurrence is within the lower Jurassic Talkeetna Formation, an approximately 2,575 meter thick sequence of volcanic and volcaniclastic rocks (Determan and Hartsock, 1966). The volcanic section near the prospect is structurally bounded on the west by the Bruin Bay Fault, a major fault system traceable for over 500 kilometers. On the east, the volcanics are unconformably overlain by upper Jurassic marine sediments (Determan and Hartsock, 1965). The Talkeetna Formation is intruded by rocks of the Aleutian range -Talkeetna Mountain plutonic belt approximately 23 km southwest of the prospect. These intrusives which consist dominantly of coarse-grained quartz diorites and quartz monzonites have been dated between 175 and 145 m.y. ( Steefel, 1987). . At Difficult Creek, the Talkeetna Formation has been divided into three major groups (Steefel, 1987). The lowest group consist of purple and green andesite flows and breccia which locally show well-developed pillows. The middle group that host the mineralization, consists of coarse-grain felsic breccias, reworked volcaniclastic rocks, crystal tuffs, and dacite flows. The upper group consists of polymitic andesitic breccias and conglomerates with minor amounts of andesitic flows. . The mineralization consists of strataform massive sulfides layers and lens which contain pyrite, chalcopyrite and sphalerite. There are no published assay results for this occurrence. William Ellis (personal communication, 1999) speculates that this occurrence is a Kuroko type massive sulfide deposit.
Comment (Workings): Workings / Exploration = The occurrence was discovered by Anaconda Minerals in 1982 as part of a exploration program at the Johnson River prospect. To date there has been detailed mapping, stream and soil geochemical surveys, and surface trenching and sampling. No assay results are available.
References
Reference (Deposit): Detterman, R.L., Reed, B.L., and Lamphere, A.A., 1965, Jurassic plutonism in the Cook Inlet region, Alaska: U.S. Geological Survey Professional Paper 525-D, p. D16-D21.
Reference (Deposit): Detterman, R.L., and Hartsock, J.L., 1966, Geology of the Iniskin-Tuxedni region, Alaska: U.S. Geological Survey Professional Paper 512, 78 p.
Reference (Deposit): Steefel, C.I., 1987, The Johnson River Prospect, Alaska: Gold rich sea-floor mineralization from the Jurassic: Economic Geology, V. 82, p. 894-914.
Reference (Deposit): Swainbank, R.C., Bundtzen, T. K., Clough A.H., and Henning, M.W., 1997, Alaska's mineral industry 1996: Alaska Division of Geological and Geophysical Surveys Special Report 51, 68 p.
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