Southeast Alaska VMS

Region Alaska, Alaska
Mineral systems
Deposit types
Critical minerals
Other minerals

Information leading to the delineation of this focus area

Basis for focus area Major regional trend of volcanogenic seafloor mineralization extends in a broadly north-south belt and is hosted within the Triassic Hyd Group stratigraphy. Prospectivity analyses highlight both known and unknown segments of the belt as being moderately to highly prospective for seafloor volcanogenic systems.
Identified resources Identified resources and current mining of copper, gold, lead, silver, and zinc (current production at Greens Creek, active exploration and resource definition at Palmer, and historical production along the belt).
Production Unknown.
Status Past and current mining (Greens Creek, advanced exploration and resource definition at Palmer, exploration along various portions of the belt).
Estimated resources Palmer: 17.7 M short tons @ 0.9% Cu, 0.3% Pb, 5.04% Zn, 0.011 oz/t Au, 1.65 oz/t Ag; Greens Creek: 19 M short tons @ 2.94% Pb, 7.79% Zn, 0.093 oz/t Au, 12.52 oz/t Ag; Niblack: 9.9 M short tons, 0.81% Cu, 1.29% Zn, 0.039 oz/t Au, 0.59 oz/t Ag.
Geologic maps Statewide geologic map database; Wilson, Hults and others (2015), scale 1:1,584,000.
Geophysical data Mostly (>90%) inadequate aeromagnetic and aeroradiometric coverage.
Favorable rocks and structures Triassic Hyd Group which includes massive and pillow basalts and fragmental basalt and andesites intercalated with siltstone, tuff, and rare rhyolite flows and dikes. The Hyd Group is a regional host to volcanogenic seafloor systems throughout southeast Alaska.
Deposits Greens Creek, Palmer, Sumdum, Alaska Tressure, Zarembo Island, NiblackKhayyam.
Evidence from mineral occurrences ARDF occurrences all along the belt.
Geochemical evidence Sediment and soil anomalies in pathfinder elements including Cu, Ag, Pb, Zn, Cd, or Co. Additional geochemical evidence comes from pan concentrates containing anglesite, cerussite, chalcopyrite, copper sulfide/oxide, galena, or sphalerite. Heavy Mineral concentrates containing Cu, Pb, Zn or Ag.
Geophysical evidence No data.
Evidence from other sources Moderate and high potential defined by prospectivity analysis; Karl and others (2016).
Comments This belt in southeast is primarily hosted in the Hyd Group stratigraphy. The southeast volcanogenic seafloor belt is world renowned, and contains one of the emerging new discoveries at the Palmer project. Historical production and resources have been defined at multiple occurrences throughout, with current production at Greens Creek. Additional deposits with similar characteristics also extend into Canada (for example, Windy Craggy).
Cover thickness and description Unknown.
Authors Douglas C. Kreiner, James V. Jones, III.
New data needs New mapping, geophysics, updated geochemical sampling.
Geologic mapping and modeling needs Mapping at 1:100,000 scale or better.
Geophysical survey and modeling needs Aeromagnetics and radiometrics collected at Rank 2.
Digital elevation data needs IfSAR coverage is complete over entire focus area.