Casca Zinc

Prospect, Active

Commodities and mineralogy

Main commodities Pb; Zn
Other commodities Ba
Ore minerals barite; galena; hematite; sphalerite

Geographic location

Quadrangle map, 1:250,000-scale CY
Quadrangle map, 1:63,360-scale B-1
Latitude 65.322
Longitude -141.079
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Casca Zinc prospect is at about 2,600 feet elevation, approximately 1/3 mile southwest of Tindir Creek, in the NE1/4 section 26, T. 6 N., R. 32 E., of the Fairbanks Meridian. This prospect is on land selected by or conveyed to Doyon, Limited. The location is accurate.

Geologic setting

Geologic description

The mineralization at Casca Zinc prospect is hosted by limestone of the Lower Cambrian Funnel Creek Formation (Brabb and Churkin, 1969). The deposits consists of fracture and open-space fillings that locally contain specular hematite, barite, and sphalerite. The sphalerite is typically massive, very fine grained, and compact, but is also found disseminated throughout the limestone (DiMarchi and others, 1993). Alteration consists mainly of silicification of fossiliferous limestone, but iron oxides and specular hematite can be locally abundant. Most of the iron oxide, alteration, and sulfide mineralization is confined to fault and fracture zones. Soil sampling programs starting in the mid-1970s have outlined areas of anomalous zinc and lead. Rock samples from Casca Zinc prospect yield as much as 18.9 percent Zn (DiMarchi and others, 1993).
Geologic map unit (-141.08138440898, 65.3217409152801)
Mineral deposit model Carbonate-hosted Zn-Pb; Appalachian Zn (Schmidt, 1997; Cox and Singer, 1986; model 32b)
Mineral deposit model number 32b
Age of mineralization Early Cambrian or younger, based on the age of the host rocks.
Alteration of deposit Iron oxide, sulfides, and silicification occur mainly along fault and fracture zones (DiMarchi and others, 1993).

Production and reserves

Workings or exploration Several soil and rock sampling programs have been carried out on the property, beginning in the mid-1970s. In 1993, a detailed mapping program was completed by ASA Inc. This property lies on Doyon, Limited selected or conveyed land.
Indication of production None

Additional comments

This property lies on Doyon, Limited selected or conveyed land. For more information, contact Doyon, Limited. This site is within the Yukon-Charley Rivers National Preserve.

References

MRDS Number 10307398

References

DiMarchi, J.J., Weglarz, T.B., Adams, D.D., Hubert, J.A., and West, A.W., 1993, 1993 annual report--Reconnaissance program, Doyon option lands: ASA Inc., 120 p. (Report held by Doyon, Limited, Fairbanks, Alaska.)
Schmidt, J.M., 1997, Shale-hosted Zn-Pb-Ag and barite deposits of Alaska, in Goldfarb, R.J., and Miller, L.D., eds., Mineral deposits of Alaska, 1997: Economic Geology Monograph 9, p. 35-65.
Reporters C.E. Cameron (ADGGS)
Last report date 4/7/2000