Haystack Mountain

Prospects, Inactive

Commodities and mineralogy

Main commodities Au
Other commodities As; Sn; W; Zn

Geographic location

Quadrangle map, 1:250,000-scale KH
Quadrangle map, 1:63,360-scale A-5
Latitude 64.163
Longitude -152.314
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Haystack Mountain prospects cover about 15 square miles and are situated in the numerous streams draining Haystack Mountain. The approximate center of the prospect area is in NW1/4SW1/4 section 5, T. 9 S., R. 24 W., of the Fairbanks Meridian. The North Fork Kuskokwim River provides access to the Haystack Mountain prospects. The southern half of Haystack Mountain, located within T. 9 S., R. 24 W., is situated on land selected by or conveyed to Doyon, Limited.

Geologic setting

Geologic description

Haystack Mountain is composed of a quartz monzonite stock (Silberman and others, 1978) intruding hornfelsed chert, siltstone, mudstone, and argillite. The sedimentary rocks are of Ordovician to Late Devonian age (Chapman and Yeend, 1981). Sillberman and others (1978) determined a K-Ar biotite age of 64.2 plus or minus 1.9 Ma for the intrusive rock from Haystack Mountain. Regionally, the area contains a system of northeast-trending strike slip and related conjugate faults associated with Cretaceous to Tertiary plutonic rocks and coeval or younger volcanic rocks (Clautice and others, 1993).
Pan concentrates collected from several streams draining the northwest, southwest, and northeast sides of Haystack Mountain contain as much as 1,650 ppb Au, 20 ppm Sn, and 135 ppm W. Stream-sediment samples contained up to 40 ppb Au, 7 ppm Sn, and 10 ppm W (Bond, 1985). A pan concentrate from a north-draining stream contained 13 ppm As, 28 ppm W, 120 ppm La, 250 ppm Ce, 29 ppm Th, and 105 ppm Sn. Two rock chip samples of gossan material contained up to 430 ppm Zn, 105 ppm Cu, 109 ppm As, 8,898 ppm Mn, and 190 ppm Sn (Clautice and others, 1993). Bond (1985) reported rock chip samples from buff-colored hornfels and black graphitic schist that contained as much as 15 ppb Au. A sample of calc-silicate hornfels contained 100 ppb Au and 776 ppm As (Clautice and others, 1993). No mineralization was observed in the Haystack Mountain quartz monzonite (Bond, 1985).
A regional stream sediment sampling, airborne radiometrics, and mapping program in 1975-76 identified several anomalies (Bond, 1985). There are no indications of production.
Geologic map unit (-152.31637713861, 64.1624569517821)
Mineral deposit model Plutonic-related mesothermal veining.
Age of mineralization Probably related to Early Tertiary plutonism.

Production and reserves

Workings or exploration A regional stream sediment sampling, airborne radiometrics, and mapping program in 1975-76 identified several anomalies (Bond, 1985). In 1985, 2 rock chip, 10 stream sediment, and 7 pan concentrate samples were collected (Bond, 1985).
Indication of production None
Production notes There are no indications of production.

Additional comments

The southern half of Haystack Mountain, located within T. 9 S., R. 24 W., of the Fairbanks Meridian, is situated on land selected by or conveyed to Doyon, Limited. For more information, contact Doyon, Limited.

References

MRDS Number 10307706

References

Bond, James, 1985, Geologic field examinations in Doyon, Limited, regional selection block 9: Doyon Limited Report 85-19, 179 p. (Report held by Doyon, Limited, Fairbanks, Alaska).
Reporters Cameron S. Rombach (ADGGS)
Last report date 11/8/1999