Location: The Fishhook prospect covers an area of approximately 2 square miles. It is location 7 of Eberlein and others (1977). It is located to the west of the Fishhook Bend of the Sixtymile River. Accessibility is limited; the Taylor highway passes about 24 miles west of the prospect. However, rough overland access is available from Canada (Curt Freeman, unpublished data, 1998). The coordinates are for the approximate center of the claim block, but the center of mineralization and prospecting could be elsewhere within the claim block. The location is accurate to within 1 mile.
Geology: The country rock within the Fishhook prospect area is augen gneiss having a possible igneous protolith (Mertie, 1931; Foster, 1970). This protolith has a possible emplacement age (inferred from dating other exposures in the region) of Devonian to Mississippian (360 Ma), with resets in the Late Jurassic (190 Ma) and Early to mid-Cretaceous (135-107 Ma) time (Dusel-Bacon and Aleinikoff, 1985). Cretaceous-Tertiary, fine-grained biotite granite, granodiorite, monzodiorite, and a coarse-grained alkali granite intrude the augen gneiss and are exposed in small outcrops at the prospect. Tertiary (?) volcanics are also present (Gill, 1977). Local structures are dominated by numerous, high-angle, NE-trending fault zones. Many subordinate fault zones in the area parallel the NE strike and possibly reflect underlying igneous activity (Curt Freeman, unpublished data, 1998). The mineralization at the Fishhook prospect appears to be structurally controlled by the NE-trending faults. Minerals include chalcopyrite, galena, gold, molybdenite, pyrite, silver, sulfosalts, and stibnite. The more highly mineralized areas occur as breccias along the NE faults. The plutonic rocks also contain elevated values of lead, silver, barium, antimony, and gold. Anomalous bismuth along some of the faults suggests a plutonic-source fluid. Extensive hydrothermal alteration and silicification is present in many of the fault zones (Curt Freeman, unpublished data, 1998). This property was examined in the 1970's as a porphyry-copper deposit, but no significant grades of copper were found. Soil sampling, rock-chip sampling, and stream-sediment sampling were done on the property in the 1970's. In 1978, a shallow drill hole was put in, but no significant mineralization was found. In recent years, soil and rock chip sampling, geologic mapping, and a ground-based magnetometer survey have been conducted (Curt Freeman, unpublished data, 1998).
Workings: Soil sampling, rock chip sampling, and stream sediment sampling were carried out in the 1970's. In 1978, one shallow drill hole was put in, but did not encounter significant mineralization. In recent years, soil and rock-chip sampling, geologic mapping, and a ground-based magnetometer survey have been conducted (Curt Freeman, unpublished data, 1998). This prospect was examined in the 1970's as a porphyry-Cu deposit, but no significant grades of copper were found (J.M. Messing, oral communication, 1998).
Age: Late Cretaceous-early Tertiary.
Alteration: Intense hydrothermal alteration and silicification is found in many of the NE-trending fault zones and in portions of intrusive units at the prospect (Curt Freeman, unpublished data, 1998).

Commodities (Major) - Ag, Au; (Minor) - Barite, Cu, Mo, Pb, Sb
Development Status: None
Deposit Model: Plutonic-related (?) ore deposit along NE-trending faults

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Mineral List

9 valid minerals.