Northern Brooks Range

Region Alaska, Alaska
Mineral systems
Deposit types
Other minerals

Information leading to the delineation of this focus area

Basis for focus area Prospectivity analyses highlight this belt as being moderate to high prospectivity for VMS systems. ARDF occurrences are present over a >1 mile trend of alteration and mineralization.
Identified resources None.
Production None recorded.
Status Past exploration limited to mapping and geochemical sampling.
Estimated resources None.
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 Carbonaceous shale and silicified mudstone associated with altered submarine bi-modal felsic tuffs and lesser mafic volcanic rocks including trachyte, trachyandesite, and basalt.
Deposits None.
Evidence from mineral occurrences ARDF occurrences including the Drenchwater trend.
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 to high potential defined by prospectivity analysis; Karl and others (2016).
Comments A known 1.2 mile trend in the Drenchwater trend has seen past exploration, but an area roughly twice the aerially extent is highlighted by high prospectivity drainage basins to the southeast along strike including significant unknown potential. This new area contains no known ARDF localities.
Cover thickness and description Unknown.
Authors Douglas C. Kreiner, James V. Jones, III.
New data needs New geologic mapping, geophysical surveys and well-constrained geochemical sampling.
Geologic mapping and modeling needs Mapping at 1:100,000 scale or better.
Geophysical survey and modeling needs Rank 1 or 2 aeromagnetics over the entire belt.
Digital elevation data needs IfSAR coverage is complete over entire focus area.