| Lat / long: | 47.09778, -88.58033 |
| Primary: | Copper |
| Secondary: | Silver |
| Ore: | Copper |
| Gangue: | Feldspar, Epidote, Quartz, Calcite, Sericite, Pumpellyite-(Mg) |
| Orebody form: | TABULAR |
| Operation type: | Unknown |
| Deposit type: | Lode |
| Production size: | Medium |
| Development status: | Past Producer |
| Production years: | 1853-1885; 1901-1925 AND POSSIBLY LATER. |
| First production started: | 1853 |
| Last production ended: | 1885 |
| Host rock: | Isle Royale Amygdaloid, Portage Lake Volcanics |
| Host type: | Basalt |
| Structure: | Syncline, Isle Royale syncline--the largest structure seen in the mine. The only fau |
| Alteration processes: | Early oxidation followed by epidotization/pumpellitization associated with copper mineralization |
| MRDS | W062231 |
| DEP | 10082868 |
| Reference | {Deposit:: BUTLER, B.S., AND BURBANK, W.S., 1929, THE COPPER DEPOSITS OF MICHIGAN: USGS PROF PAPER NO. 144, 238 PP.}{Deposit:: WHITE, W.S., 1956, GEOLOGIC MAP OF THE CHASSELL QUADRANGLE, MICHIGAN: USGS MAP MF-43, SCALE 1:24000.}{Deposit:: JOHNSON, A.M. AND GROTH, E.H., 1998, INVENTORY OF UNDERGROUND MINES, HOUGHTON COUNTY, SITE ID 310016, MICHIGAN DEPARTMENT OF NATURAL RESOURCES.}{Production:: BUTLER, B.S., AND BURBANK, W.S., 1929, P. 87.} |
| Reporter | Sutphin, D.M. (Cannon, W.F.), Mason Jr., G.T., Anderson, Arlene (M. Gere) |