Callahan mine area

Region East, Northeast
Mineral systems
Deposit types
Critical minerals
Other minerals

Information leading to the delineation of this focus area

Basis for focus area Polygons extracted from Hibbard and others (2006).
Identified resources Historical production of copper, lead, silver, and zinc.
Production Production from the Callahan pit totaled about 800,000 tons of ore, with an average ore grade of 4.91% Zn, 1.30% Cu, 0.35% Pb, and 0.50 oz/ton of Ag. (Ayuso and others, 2013).
Status Past mining. Designated USEPA Superfund site now under reclamation. Five million tons of sulfide-bearing waste and unprocessed ore remained on-site bordering ponds and tidal flats that comprise the estuary proper.
Estimated resources Unknown.
Geologic maps Osberg and others (1985), scale 1:500,000; Stewart and Tucker (1999), scale 1:62,500.
Geophysical data Inadequate aeromagnetic and aeroradiometric coverage.
Favorable rocks and structures Cambrian Ellsworth Schist and Castine Volcanics: metamorphosed interlayered mafic and felsic volcanic rocks and flows.
Deposits Douglas copper mine (MRDS dep_id: 10306809), Emerson and North Castine (MRDS dep_id: 10100490), Penobscot unit (MRDS dep_id: 10218684), Tapley mine (MRDS dep_id: 10145659), Deer Isle mine (MRDS dep_id: 10084400), Black Hawk-Blue Hill Zn-Cu (MRDS dep_id: 10073177).
Evidence from mineral occurrences MRDS; Mosier and others (2009); Stephens and others (1984).
Geochemical evidence Favorable mineralogy and rock type.
Geophysical evidence Unknown.
Evidence from other sources Unknown.
Cover thickness and description Some exposure at the surface.
Authors Nora K. Foley, Gregory J. Walsh.
New data needs Geophysics.
Geologic mapping and modeling needs Unknown.
Geophysical survey and modeling needs High resolution aeromagnetic and aeroradiometric coverage.
Digital elevation data needs Lidar complete.