Mosquito Prospect, Southeast Fairbanks Census Area, Alaska, USAi

Regional Level Types
Mosquito Prospect	Prospect
Southeast Fairbanks Census Area	Census Area
Alaska	State
USA	Country

This prospect lies within Doyon Ltd. selected lands. For more information, contact Doyon Ltd.
Location: The Mosquito prospect is located within sections 3,4, 9, and 10, T. 24 N., R. 10 E., of the Copper River Meridian. It is location 1 of Singer and others (1976), and location 9 of Eberlein and others (1977). It is 6 miles south of the Mosquito Fork of the Fortymile River. The location is accurate to within 1/2 mile. The coordinates correspond to the approximate center of the prospect. The location is accurate to within 1/2 mile.
Geology: The Mosquito prospect consists of disseminated chalcopyrite, magnetite, molybdenite, and pyrite in an intrusion of hydrothermally altered quartz monzonite and quartz latite porphyry (Singer and others, 1976). The area contains small, isolated outcrops of felsic volcanic rocks that are reported to be more extensive than shown on Foster and others (1976) geologic map. The most common texture is porphyritic with a fine- to medium-grained groundmass. Phenocrysts include euhedral and subhedral quartz, some of which is mildly strained, and altered feldspar, biotite, and hornblende. The rocks range from slightly altered to so completely altered that the original texture and composition cannot be determined. Sericite, clay minerals, quartz, and chlorite are the most common alteration products. However, limonite and carbonate also occur (Foster and others, 1976). Potassium feldspars in a vein cutting the intrusion have an integrated 40Ar/39Ar age of 70.0 + / - 0.3 Ma (Newberry and others, 1996). The prospect has anomalous values in gold, bismuth, and tellurium, suggesting that it is an extension of the Carmacks porphyry belt (Alaska Division of Geological and Geophysical Surveys, 1993; Burleigh and Lear, 1994; Newberry and others, 1996). In 1974-75, some drilling and sampling took place on the prospect. Grades of up to 0.17% Mo were reported, but it is unclear if they refer to the Mosquito prospect or the Peternie prospect (TC022) (Singer and others, 1976).
Workings: In 1970-73, Resource Associates of Alaska did mapping, trenching, rock and soil sampling, and completed 3 miles of IP lines. In 1974-75, Cities Services did 788 feet of drilling in 2 holes, and 2.5 miles of IP lines. This was followed in 1979 by WGM Inc., who carried out petrographic analyses, mapping at 1:10,000 and 1:5,000 scales, a geochemical soil and rock sampling grid, and magnetics on the soil grid. In 1981 Arctic Resources Inc. analyzed 22 miles of soil traverses, and in 1984 Doyon Ltd. briefly visited the prospect. In 1990 Doyon Ltd. conducted rock, soil and stream sediment sampling for gold (Doyon Ltd., 1998).
Age: If this prospect represents a porphyry Cu-Mo deposit, the age of mineralization is likely the same or close to the age of alteration, reported by Newberry and others to be 70.0 +/- 0.3 Ma (1996).
Alteration: Zones of quartz-sericite-pyrite, quartz-magnetite, and epidote-chlorite-quartz pyrite alteration (Doyon Ltd., 1998).

Commodities (Major) - Cu, Mo; (Minor) - Ag, Pb, Zn
Development Status: None
Deposit Model: Porphyry Cu-Mo deposit (Cox and Singer, 1986; model 21a)

Other Databases

Link to USGS - Alaska:	TC015

Other Regions, Features and Areas containing this locality

References