Prospector East

Prospect, Active

Commodities and mineralogy

Main commodities Ag; Au; Bi; Cd; Pb
Ore minerals galena; gold
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale CH
Latitude 67.565
Longitude -148.1882
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Prospector East prospect is at an elevation of about 3500 feet along the ridge about 1.2 miles north-northeast of Little Squaw Peak. It if about 0.3 mile south of the center of section 27, T. 32 N., R. 3 W. The location is accurate.

Geologic setting

Geologic description

Placer gold was discovered in the Chandalar area on Little Squaw Creek (CH039) in 1902 (Barker, and Bundtzen, 2005; Barker, 2007; Barker and others, 2009). By 1909, four quartz veins had been discovered and many more were located prior to WWI. Most of the important properties in the district were consolidated by William Sulzer from 1909 to 1941. Those properties were taken over in 1946 into what became the Little Squaw Mining Company in 1959 and the Little Squaw Gold Mining Company in 1968. In 2008, the Little Squaw Gold Mining Company became the Goldrich Mining Company, the operator as of early 2010 (Goldrich Mining Company, 2010). From 1967 to 1999, Little Squaw Gold Mining Company leased some of their Chandalar lode and placer ground for mining and/or exploration to a succession of companies, notably the Chandalar Gold Mining and Milling Company (1967-1971), Noranda Mining (1974-1976), the Chandalar Development Corporation (1980-1983), and Gold Dust Mines (1989-1999). There was some earlier small lode production from the district but the first documented gold produced from the lodes was 870 ounces produced from 1967 to 1980 from the Mikado Mine by the Chandalar Gold Mining and Milling Company. In 2003, Little Squaw Gold Mining Company and its direct descendent Goldrich Mining Company began an aggressive exploration program for lode and placer deposits over a large block of land that covers almost all of the know deposits in the Chandalar area and as of early 2010, that effort continued (Goldrich Mining Company, 2010).
The geology of the Chandalar area is dominated by a system of west-northwest-trending regional faults including a major thrust fault in the southern part of the district and a series of major high-angle faults through the center of the area (Bundtzen and Laird, 2009a, 2009b). These faults separate the rocks into two major units, a west-northwest-trending Upper Plate unit about 3 miles wide in the center of the area and a Lower Plate unit to the north and south. The contact of the two units is a major thrust fault on the south side of the Upper Plate rocks and a high-angle fault on the north side. Most of the Upper Plate rocks consist of Devonian upper-Greenschist-facies metamorphic rocks, mainly carbonaceous schist; quartz-chlorite-muscovite schist, schist and phyllite derived from turbidites that comprise the Mikado Phyllite, metamorphosed calcareous sandstone, and quartz-muscovite schist. The Lower Plate rocks consist of Devonian, upper-Greenschist facies metamorphic rocks, mainly metamorphosed volcanic agglomerates, chlorite-rich tuffaceous schist, quartz-mica schist derived from mudstone, mica-quartz schist, and quartzite. Both the Upper and Lower Plate rocks are cut by irregular masses, dikes and sills of greenstone, metagabbro, and metadiorite of unknown age. Most of the mineral deposits in the Chandalar area are in the Upper Plate rocks and the deposits often occur along the regional, steep-to-vertical, west-northwest-trending faults. There is an additional set of north-northeast-trending conjugate faults that offset the Upper Plate rocks and at least some of the mineralization may be localized at the intersections of the regional west-northwest-trending faults and the conjugate faults.
The vein at the Prospect East prospect is not exposed but can be traced northwest for about 400 feet in shallow trenches and a short caved adit. In the Chandalar district, it is uniquely a silver prospect (Barker and Bundtzen, 2004, Barker, 2006; Barker, 2007; Barker and others, 2009). Two samples contained 171 and 740 parts per million (ppm) silver, 2.94 and 2.50 ppm gold, and up to 11.65 percent lead, 1,120 ppm bismuth, and 104 ppm cadmium. Barker (2009) considers the mineralization to be the northwest extension along the Pioneer fault of the mineralization at the Pioneer and Grubstake East prospects (CH110). The gold veins in the Chandalar district are considered mesothermal (Barker and Bundtzen, 2004) by comparison with similar deposits elsewhere and consideration of fluid inclusion and oxygen and lead isotope studies of the Chandalar mineralization (Ashworth, 1983; Rose and others, 1988; Gacetta and Church, 1989).
Geologic map unit (-148.190935976384, 67.5646184421334)
Mineral deposit model Silver-lead-gold-quartz vein.
Age of mineralization Possibly Middle Cretaceous based on the assertion of Dillon (1982) that the gold-quartz veins of the central Brooks Range are that age. However, there is no definitive data for the age of the veins of the Chandalar area.
Alteration of deposit Not noted specifically.

Production and reserves

Workings or exploration A few old trenches and a short, caved adit. As of early 2010, this is one of the sites being studied by Goldrich Mining Company in their intensive exploration of the Chandalar area.
Indication of production None
Reserve estimates None.
Production notes None.

References

References

Ashworth, K.K., 1983, Genesis of gold deposits at the Little Squaw mines, Chandalar mining district, Alaska: Bellingham, Western Washington University, M.Sc. thesis, 98 p.
Ashworth, (Lamal) Kate, 1984, Fluid inclusion study of the Eneveloe Vein, Chandalar Mining District: Private Report, Chandalar Development Associates, 8 p. (in files of the Goldrich Mining Company).
Barker, J.C., 2006, Chandalar Mining District, a report of findings and recommendations, 2005: Unpublished report for Little Squaw Gold Mining Company, 93 p. (on the Internet at http://www.goldrichmining.com/Files/corporate/2005AnnualReport011906.pdf, as of February 14, 2010).
Barker, J.C., 2007, Chandalar Mining District, Annual Report of findings for 2006; Unpublished report for Little Squaw Gold Mining Company, 124 p. (On the Internet at http://www.goldrichmining.com/Files/chandalar/chandalar_barker_rpt_2007.pdf, as of February 14, 2010).
Barker, J.C., and Bundtzen, T.K., 2004, Gold deposits of the Chandalar Mining District, Northern Alaska: An information review and recommendations: Unpublished report for the Little Squaw Gold Mining Company, 165 p. (in files of the Goldrich Mining Company).
Barker, J.C., Murray, R.B., Keener, J.O., and Martin, P.L., 2009, Evaluation of the Chandalar mining property: Unpublished report prepared for Goldrich Mining Company, 165 p. (on the Internet at http://www.goldrichmining.com/Files/chandalar/Chandalar_tech_rept_4_15_09.pdf (as of February 14, 2010).
Goldrich Mining Company, 2010, Chandalar, Alaska; Project overview: http://www.goldrichmining.com/pages/prop_chan_over.htm (as of February 16, 2010).
Reporters D.J. Grybeck (Contractor, U.S. Geological Survey)
Last report date 4/2/2010