Gold Hill

Prospect, Active

Alternative names

Accident

Commodities and mineralogy

Main commodities Ag; Au; Cu; Fe; Pb; Sb; Zn
Ore minerals arsenopyrite; chalcopyrite; galena; gold; pyrite; pyrrhotite; sphalerite; stibnite
Gangue minerals ankerite; quartz

Geographic location

Quadrangle map, 1:250,000-scale HE
Quadrangle map, 1:63,360-scale A-1
Latitude 63.1902
Longitude -147.2809
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Gold Hill prospect is at an elevation of about 4,800 feet, just west of the summit of Gold Hill between Lucky Gulch and White Creek. It is about 0.4 mile south of the center of section 12, T. 20 S., R. 3 E., of the Fairbanks Meridian. The location is accurate.

Geologic setting

Geologic description

The Gold Hill prospect is one of four deposits that was explored by CanAlaska Resources Ltd. from 1983 to at least 1996 in the Rainbow Hill project. It and the nearby Lucky Top (HE210), Lucky Saddle (HE215), and TMC (HE211) prospects share a similar origin and general characteristics. The Rainbow Hill project is described in considerable detail by Adams (1996) and Freeman (2002) and most of what follows is based on their work.
The rocks in the area consist of folded Jurassic to Cretaceous argillite, graywacke, siltstone, and mafic tuff that were intruded by small stocks and dikes of Tertiary and Cretaceous gabbro and diorite. The rocks underwent lower-greenschist- to amphibolite-grade metamorphism in the Cretaceous and early Tertiary. Airborne geophysical data suggest that the Gold Hill/Lucky Top area that roughly coincides with the Rainbow project is underlain by a shallow, structurally deformed meta-igneous complex. The regional structure is dominated by a set of east-trending thrust faults and cross-cutting high-angle faults. A set of northwest-trending, high-angle faults and dikes associated with the mineralization is offset by northwest- and northeast-trending faults.
The mineralization in the Rainbow project consists of zones of stacked, sulfide-bearing, ankerite-quartz veins and stockworks that strike east and dip variably to the north and south. The sulfides in the veins and stockworks are mainly pyrite and arsenopyrite; minor amounts of pyrrhotite, chalcopyrite, galena, stibnite, and sphalerite occur widely, as does visible gold. Abundant sulfides usually indicates high gold values. The auriferous zones typically have a central area of intense silicification, sericitization, and carbonatization, that weakens outward. Sericite from the veins has been dated at 57.6 to 63.1 Ma by argon-argon methods.
Although there had been some earlier work on the gold veins in the Gold Hill/Lucky Top area (Moffit, 1912; Ross, 1933; Tuck, 1938), the first extensive exploration in the area was in 1983 when CanAlaska began a program of surface mapping, outcrop sampling, soil geochemical surveys, trenching, and ground geophysical surveys. The work identified numerous zones of hornfels alteration and diorite dikes. In 1996, they drilled 5 holes totaling 1,400 feet on the Gold Hill prospect. The drilling intersected numerous diorite dikes and breccia zones. Most of the holes ware in pervasive sericite-carbonate-quartz and tourmaline alteration; numerous sections of the holes intersected persistent anomalous gold values up to 1,950 parts per billion. The drilling did not penetrate the Gold Hill diorite stock which is exposed on the surface less than 1,000 feet west of the drill sites; the stock was considered an attractive target.
Geologic map unit (-147.283158987318, 63.1897532253122)
Mineral deposit model Low-sulfide Au-quartz vein (Cox and Singer, 1986; model 36a).
Mineral deposit model number 36a
Age of mineralization About 60 Ma based on the age of sericite from the quartz veins.
Alteration of deposit The mineralization is associated with pervasive sericite-carbonate-quartz alteration; local hornfelsing and tourmalinization.

Production and reserves

Workings or exploration Although there had been some earlier work on the gold veins in the Gold Hill/Lucky Top area ( Moffit, 1912; Ross, 1933; Tuck, 1938), the first extensive exploration in the area was in 1983, when CanAlaska began surface mapping, sampling, and trenching. In 1996, they drilled 5 holes totaling 1,400 feet on the Gold Hill prospect.
Indication of production None

References

MRDS Number A011299

References

Reporters D.L. Stevens (Stevens Exploration Management Corporation), D.J. Grybeck (Port Ludlow, WA)
Last report date 6/5/2008