Chelan Butte

Region West, Northwest
Mineral systems
Deposit types
Other minerals

Information leading to the delineation of this focus area

Basis for focus area Cluster of tungsten-bearing prospects; porphyry-related.
Identified resources Past production of gold.
Production Holden-Campbell mine produced a considerable amount of Au ore from polymetallic veins (Derkey and others, 1990).
Status Past mining.
Estimated resources Unknown.
Geologic maps Washington Division of Geology and Earth Resources (2016), scale 1:100,000.
Geophysical data Inadequate aeromagnetic and aeroradiometric coverage.
Favorable rocks and structures Tonalitic gneiss of the Cretaceous Methow Gneiss cut by Eocene (?) dikes.
Deposits Holden-Campbell mine (MRDS dep_id: 10008486), Minnie mine (MRDS dep_id: 10056011), Methow mine (MRDS dep_id: 10104287).
Evidence from mineral occurrences MRDS.
Geochemical evidence Assays indicate 0.25% WO3 at Holden-Campbell mine; 0.25% scheelite at Minnie mine.
Geophysical evidence Unknown.
Evidence from other sources Unknown.
Comments The deposit area is largely covered by state owned and national forest land. Proximity to the town of Methow and its watershed may be a concern for future development.
Cover thickness and description Exposed at surface and reaches to some depth.
Authors Daniel W. Eungard.
New data needs High resolution mapping and geophysics.
Geologic mapping and modeling needs Partial mapping of three to four quadrangles at 1:24,000 scale or better resolution.
Geophysical survey and modeling needs High resolution aeromagnetic and aeroradiometric survey. Gravity may not be helpful with the similarity to the host/intrusive rock types.
Digital elevation data needs Lidar in progress or planned/funded.