| 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. |
