Zincabou

Prospect, Inactive

Commodities and mineralogy

Main commodities Cu; Zn
Other commodities Au; Pb
Ore minerals arsenopyrite; chalcopyrite; galena; pyrite; sphalerite
Gangue minerals carbonates; quartz

Geographic location

Quadrangle map, 1:250,000-scale MZ
Quadrangle map, 1:63,360-scale A-4
Latitude 65.0035
Longitude -154.856
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Zincabou prospect is at an elevation of about 3,100 feet on a northern ridge of the Kokrines Hills, approximately 6 miles north of Horner Hot Springs. The prospect covers less than one square-mile and extends into the Ruby quadrangle. The site is in the NE 1/4 of section 5, T. 6 S., R. 20 E., Kateel River Meridian. The location is accurate to within 2,000 feet.

Geologic setting

Geologic description

The rocks in the vicinity of the Zincabou prospect are mainly greenschist-grade, lower Mesozoic and upper Paleozoic, marine basalt and pelitic sedimentary rocks, and mafic and ultramafic intrusive rocks. To the east, they are in thrust contact with lower-plate, pre-Cretaceous, amphibolite-grade schist, gneiss, and marble (Patton and others, 1977; Dillon and others, 1983). Thrust breccias up to 5 feet thick separate the overlying greenschist-grade rocks (greenstone) from the amphibolite-grade schist and gneiss (North Star Exploration Inc., 1999 [ DLR99-33]). Zincabou Creek flows parallel to the schistosity and probable bedding of the country rocks (North Star Exploration Inc., 1999 [DLR99-33]). Aplite, pegmatite, and leucocratic apophyses of Cretaceous granite also crop out in the prospect area (Dillon and others, 1983).
Mineralization consists of pyrite, arsenopyrite, sphalerite, chalcopyrite, and galena in quartz-carbonate veins and stockworks that cut the thrust breccias (North Star Exploration, Inc., 1999 [DLR 99-33]). In the 1970s, WGM, Inc. located 2 mineralized breccia zones, 3.5 to 5 feet thick, that are roughly concordant with the contact between greenstone and gneiss. Graphitic schist and chlorite schist contain zones of disseminated sulfides as much as 15 feet thick, and quartz-carbonate-sulfide veins. Rock samples contained as much as 7.4 parts per million (ppm) silver, 343 ppm copper, 1 percent zinc, and 4,000 ppm lead. Copper and gold values are erratic but locally high. A sample of a rusty colored, weakly silicified quartzite containing 10 percent pyrite, mainly along fracture surfaces; it assayed 1.6 ppm gold, 0.8 ppm silver, 148 ppm copper, and 556 ppm zinc (DiMarchi and others, 1991). The prospect has been variously interpreted as structurally-controlled epithermal veins, skarn, a stockwork vein system, or a massive-sulfide replacement deposit (North Star Exploration Inc., 1999 [DLR 99-33]).
The Zincabou prospect was discovered by WGM, Inc. in 1975 during a soil sampling program following a regional stream-sediment sampling program (North Star Exploration Inc., 1999 [DLR 99-33]). Anomalous values of zinc and lead in stream-sediment samples were traced to a thrust breccia cut by arsenopyrite-bearing veins carrying significant zinc, lead, copper, and manganese values. WGM, Inc. worked in the area until 1979; their work included regional stream-sediment sampling and airborne radiometric surveys. Central Alaska Gold Co. evaluated the Zincabou prospect in 1990. North Star Exploration, Inc. conducted sampling and geologic mapping for Doyon Limited in 1998 (North Star Exploration, Inc., 1999 [DLR 99-33]).
Geologic map unit (-154.858502545099, 65.0029158932689)
Mineral deposit model Kipushi Cu-Pb-Zn (Cox and Singer, 1986; model 32c); Polymetallic veins (Cox and Singer, 1986; model 22c); Creede epithermal (Zn)-Au (Cox and Singer, 1986; model 25b)
Mineral deposit model number 22c, 25b, 32c
Alteration of deposit Silicification.

Production and reserves

Workings or exploration The Zincabou prospect was discovered by WGM, Inc. in 1975 during a soil sampling program following a regional stream-sediment sampling program (North Star Exploration Inc., 1999 [DLR 99-33]). Anomalous values of zinc and lead in stream-sediment samples were traced to a thrust breccia cut by arsenopyrite-bearing veins carrying significant zinc, lead, copper, and manganese values. WGM, Inc. worked in the area until 1979; their work included regional stream-sediment sampling and airborne radiometric surveys. Central Alaska Gold Co. evaluated the Zincabou prospect in 1990. North Star Exploration, Inc. conducted sampling and geologic mapping for Doyon Limited in 1998 (North Star Exploration, Inc., 1999 [DLR 99-33]).
Indication of production None

Additional comments

The Zincabou Creek prospect is on lands selected by Doyon, Limited. For further information, contact Doyon, Limited, 1 Doyon Place, Suite 300, Fairbanks, Alaska 99701-2941.

References

References

DiMarchi, J.J., Weglarz, T.B., Dickey, C.F., Laux, D.P., Smith, M.T., Toro, J., and Kurtz, J.P., 1991, Central Alaska Gold Co. 1990 annual report, Alaska field operations - Doyon option volume 7 plates, Fortymile central, Fortymile south, mid-Yukon, Nikolai, and East Holy Cross blocks: Doyon, Ltd. Report 91-8d. (Report held by Doyon, Ltd., Fairbanks, Alaska).
North Star Exploration Company, 1999, North Star 1998 Annual Report, Block 18, Middle Yukon, DLR 99-33 (Report held by Doyon, Limited, Fairbanks, Alaska).
Reporters G.E. Graham, D.J. Szumigala (Alaska Division of Geological and Geophysical Surveys)
Last report date 1/10/2005