Unnamed (upper Peace River)

Prospect, Active

Commodities and mineralogy

Geographic location

Quadrangle map, 1:250,000-scale CA
Quadrangle map, 1:63,360-scale B-5
Latitude 65.4544
Longitude -161.0809
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is on the north side of the headwaters of the Peace River, about 4.8 miles east-northeast of the top of Granite Mountain. It is about 0.6 mile southwest of the center of section 25,T. 1 N., R. 12 W., of the Kateel River Meridian. The location is accurate.

Geologic setting

Geologic description

The upper Peace River area is underlain by a small satellitic stock of the Late Cretaceous Granite Mountain pluton. The stock is composed of several varieties of syenite. Locally, the syenite is cut by quartz veins and contains abundant disseminated pyrite cubes, some fine-grained molybdenite, and abundant magnetite and purple fluorite. A canary-yellow alteration product found both in the veins and in the syenites was identified as ferrimolybdite. The syenite is bleached, oxidized, and contains disseminated pyrite, and where it is cut by quartz-pyrite veins, sporadic molybdenite. The syenite and associated quartz veins locally contain anomalous amounts of molybdenum, bismuth, silver, copper and lead. Numerous rock and soil samples were collected from this area by Miller and Elliott (1969). One rock sample contained: 150 parts per million (ppm) silver, 30 ppm molybdenum, 3,000 ppm lead, 700 ppm copper, and 0.04 ppm gold. Another rock sample contained: 1.5 ppm silver, greater than 2,000 ppm molybdenum, 500 ppm copper, and 300 ppm lead. Both were grab samples of oxidized syenite.
Gault and others (1953) collected pan-concentrate stream-sediment samples from this area in their search for uranium. Their samples contained anomalously high concentrations of uranothorianite and other metallic minerals, including galena, chalcopyrite, bornite, tetradymite, sphalerite, pyrite, and pyrrhotite. Intergrowths of galena, sphalerite, chalcopyrite, pyrite, and gummite were observed in some mineral grains. The mineral associations suggested to them that the uranium minerals are derived from a sulfide-bearing lode (or vein), rather than occurring as accessory minerals in in granitic rocks.
Linux Gold Corp. (2007) located 16 mining claims on this prospect in March 2005 and began mapping the geology at the surface and sampling in August, 2005 (Linux Gold Corporation 2007). As described by Adams (2007), the deposit is associated with a small stock of pinkish, fine- to medium-grained Cretaceous hornblende-biotite nepheline syenite that intrudes undifferentiated volcanic rocks. The exposure in the area is poor but the stock is at least a half mile across. Garnet-bearing syenite crops on the ridge to the northeast.
The mineralization is largely hosted in the syenite but locally occurs in pyroxenite or altered andesite near the contact of the stock. Gossans occur locally. The syenite has undergone weak to strong phyllic alteration and is locally intensely silicified. Five types of mineralization are recognized: 1) weakly altered syenite with sparse disseminated sulfides, 2) altered syenite with well-developed sulfides, 3) altered syenite with quartz-sulfide veinlets, 4) highly altered syenite with sulfide veinlets, and 5) highly silicified syenite breccia with disseminated sulfides. The sulfides are ubiquitous fine-grained pyrite and locally fine-grained molybdenite, often accompanied by fluorite. Surface oxidation has formed hematitic surface coatings and hematite along fracture fillings; locally, bright-yellow ferromolybdite from the oxidation of molybdenite is abundant. Samples of the syenite contain highly anomalous silver, lead, bismuth, copper, tungsten, antimony, uranium, and thorium. Four samples contained up to 306 parts per billion gold, 83.3 parts per million (ppm) silver, 900 ppm arsenic, 139 ppm bismuth, 6,290 ppm copper, 1,135 ppm molybdenum, 144 ppm lead, 1,001 ppm antimony, 10.9 ppm tin, 137.5 ppm thorium, 46.20 ppm uranium, 190.50 ppm tungsten, and 1,155 ppm zinc.
Adams (2007) considers the mineralization to be a highly fractionated, alkaline porphyry-Mo deposit, prospective for uranium and rare-earth elements.
Geologic map unit (-161.083544076853, 65.4537283556062)
Mineral deposit model Highly-fractionated alkaline porphry-molybdenum deposit.
Age of mineralization Probably Late Cretaceous.
Alteration of deposit The syenite that hosts the mineralization has undergone weak to strong phyllic alteration and is locally intensely silicified.

Production and reserves

Workings or exploration The area was mapped by the U.S. Geological Survey and examined by various exploration companies beginning in the 1950s. Linux Gold Corp. located 16 mining claims on this prospect in March 2005 and initiated surface geology studies and sampling in August, 2005. Surface and geochemical work continued in 2006.
Indication of production None

References

MRDS Number A013495; A015720; D002613

References

Adams, D.D., 2007, Geologic report on the Granite Mountain property, Koyuk Mining District, Candle B-5 and C-5 quadrangles, west-central Alaska: Unpublished Technical Report for the Linus Gold Corp., 71 p. (posted on www.sedar.com on February 8, 2008).
Linux Gold Corporation, 2007: (http://www.integratir.com/newsrelease.asp?news=2130980673&ticker=LNXGF&lang=EN&title=null) (as of April, 2007)
Reporters Anita Williams (Anchorage, AK); Travis Hudson (Applied Geology, Inc.); D.J. Grybeck (Port Ludlow, WA)
Last report date 6/5/2008