Ginger

Prospect, Undetermined

Commodities and mineralogy

Main commodities Ag; Au; Cu
Ore minerals azurite; chalcopyrite; magnetite; malachite; pyrite

Geographic location

Quadrangle map, 1:250,000-scale CH
Quadrangle map, 1:63,360-scale C-5
Latitude 67.7085
Longitude -149.2818
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Ginger prospect is along the ridge between Big Spruce Creek and Sheep Creek, about 3.7 miles northwest of the west peak of Horace Mountain. It is about 1.0 mile south of peak 5147 and about 0.5 mile north-northeast of the center of section 11, T. 33 N. R. 8 W. The location is accurate. Kurtak and others (2002) include a map showing the regional geology of the area and the location of this and the other deposits of the Chandalar Copper Belt.

Geologic setting

Geologic description

The Ginger prospect was discovered by Bear Creek Mining Company in 1967 in what would would become known as the Chandalar Copper Belt (Kurtak and others, 2002). Bear Creek explored the property until 1970 and from then to the 1980s WGM studied the deposit in conjunction with their work along the Copper Belt. Apparently, the work at the Ginger prospect consisted only of mapping and sampling, and geochemical and geophysical surveys. (Kurtak and others, 2002).
The Ginger prospect is a skarn deposit in Devonian Skajit Limestone that structurally overlies Ordovician phyllite, marble, and calcareous schist (Kurtak and others, 2002). Discontinuous masses of skarn crop out for 2.5 miles from peak 4109 to peak 5147. The Ginger prospect is in skarn that covers an area about 1,000 feet by 3,000 feet, about a mile south of peak 5147. The skarn contains zones of rubblecrop up to 50 by 100 feet in area with chalcopyrite, pyrite, and copper staining. Eight samples contained an average of 1.8 percent copper and 12.2 parts per million (ppm) silver. Three of the samples contained 548 to 1,201 parts per billion gold. Three samples of quartz-sericite schist next to the skarn contained 5,467 ppm copper and 3.3 ppm silver. Newberry and others (1986) concluded that the mineralogy, mineralization, and alteration of the skarns in the Chandalar Copper Belt suggest that they are continental-margin, porphyry-related copper skarns. The deposits along the belt are generally considered to be Devonian and genetically related to several meta-granodiorite plutons along the belt, notably the Horace Mountain pluton to the southeast (Dillon and others, 1996).
Geologic map unit (-149.284561933775, 67.7080999219741)
Mineral deposit model Cu skarn deposits (Cox and Singer, 1986; model 18b).
Mineral deposit model number 18b
Age of mineralization Devonian(?) based on Early Devonian Pb/Pb zircon ages from the nearby Baby Creek batholith and Horace Mountain plutons (Dillon and others, 1996).
Alteration of deposit Copper skarn developed in limestone and calcareous rocks.

Production and reserves

Workings or exploration The Ginger prospect was discovered by Bear Creek Mining Company in 1967 in what would would become known as the Chandalar Copper Belt. Bear Creek explored the property until 1970 and from then to the 1980s WGM studied the deposit in conjunction with their work along the Copper Belt. Apparently, the work at the Ginger prospect consisted of mapping and sampling and geophysical and geochemical surveys (Kurtak and others, 2002).
Indication of production None
Reserve estimates None.
Production notes None.

Additional comments

This prospect is on Doyon Ltd. selected lands; for more information, contact Doyon Ltd., Fairbanks, Alaska.
MAS No. 0020310059

References

MRDS Number A012141

References

Kurtak, J.M., Klieforth, R.F., Clark, J.M., and Maclean, E.A., 2002, Mineral investigations in the Koyukuk mining district, northern Alaska, 2 vols.: Bureau of Land Management, Alaska Technical Report 50, 845 p.
Newberry, R.J., Allegro, G.L., Cutler, S.E., Hagen-Levelle, D.D., Adams, D.D., Nicholson, L.C., Weglarz, T.B., Bakke, A.A., Clautice, K.H., Coulter, G.A., Ford, M.J., Myers, G.L., and Szumigala, D.J., 1997, Skarn deposits of Alaska, in Goldfarb, R.J., and Miller, L.D., eds., Mineral Deposits of Alaska: Economic Geology Monograph 9, p. 355-395.
Newberry, R.J., Dillon, J.T., and Adams, D.D., 1986, Regionally metamorphosed calc-silicate-hosted deposits of the Brooks Range, northern Alaska: Economic Geology, v. 81, p. 1728-1752.
Nicholson, L.M., 1990, Porphyry copper, copper skarn, and volcanogenic massive sulfide occurrences in the Chandalar copper district, Alaska: Fairbanks, University of Alaska, M.Sc. thesis, 164 p.
Nicol, D.L., 1983, Evaluation of the mineral potential of Doyon Ltd.'s Block 5 and 22 (unpublished report 83-04 for Doyon Ltd., (on file at Doyon Ltd., Fairbanks, Alaska).
WGM Inc., 1979, 1978 Doyon Ltd. annual progress report, Block 5 Luna volcanogenic massive sulfide and associated base-metal deposits and anomalies of the Chandalar Copper Belt: Unpublished report 79-21 for Doyon Ltd., 35 p. (on file at Doyon Ltd., Fairbanks, Alaska).
WGM Inc., 1980, 1979 annual profess report, Block 5-Wiseman Chandalar Cop[er Belt: Unpublished report 80-06 for Doyon Ltd., 28 p. (on file at Doyon Ltd., Fairbanks, Alaska).
Reporters J.M. Britton (Anchorage, Alaska); D.J. Grybeck (Contractor, U.S. Geological Survey)
Last report date 4/18/2010