| GMRAP ID | 3434 |
|---|---|
| Alternate names | Unnamed (at head of Geroe Creek), MAS |
| Tract name | Brooks Range (003pCu5008) |
| Site status | prospect |
| Country | United States |
|---|---|
| State or province | Alaska |
| Geographic location | -148.814, 67.6804 |
| Geologic map unit | -148.814, 67.6804 |
| Nearby data |
| Deposit type | Porphyry copper |
|---|---|
| Age (Ma) | 395Ma |
| Age determination method | Pb-Pb |
| Age range | 395.0 Ma, 388.0 Ma, 381.0 Ma (Pb-Pb) (Inferred from ages from the nearby Baby Creek batholith and Horace Mountain plutons.) |
| Age reference | Dillon and others (1996) |
| Minerals | chalcopyrite, molybdenite, pyrite |
| Tectonic setting | mixed |
| Stratigraphic age | Devonian(?) |
| Development status | Prospect |
|---|---|
| Major commodities | Au, Cu, Mo |
| Minor commodities | Pb |
| Gold-Moly ratio | -9999 |
| Comments | One of several quartz stockworks and altered zones in the northeast-trending belt of Devonian peraluminous biotite-muscovite granite of the Baby Creek batholith and Devonian, metaluminous biotite-hornblende granite and granodiorite of the Horace Mountain pluton. Sericitization and propylitization of porphyritic host rocks; veinlets in stockworks are accompanied by intense quartz-sericite-chlorite-(+/- epidote) alteration. A block of 239 claims was staked over this prospect in 19751976. |
|---|---|
| Study area name | United States |
| References | U.S. Geological Survey (2014a); Newberry and others (1986); Kurtak and others (2002); Dillon and others (1996) |
| Site reference | U.S. Geological Survey National Mineral Resource Assessment Team (2002) |