Unnamed (in headwaters of Nugget Gulch)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Au
Other commodities Cu
Ore minerals gold; pyrite
Gangue minerals calc-silicates; carbonate; quartz

Geographic location

Quadrangle map, 1:250,000-scale EA
Quadrangle map, 1:63,360-scale B-1
Latitude 64.3185
Longitude -141.1568
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is located at the hig point of the ridge between Nugget Gulch and the western branch of Sam Patch Creek. The coordinates are the approximate center of the occurrence ,on the boundary between sections 10 and 11, T. 7 S., R. 33 E., of the Fairbanks Meridian; the location is only accurate within 1 mile. This occurrence is located within Doyon, Ltd. selected or conveyed land.

Geologic setting

Geologic description

The rocks in the vicinty of this occurrence include Paleozoic quartz-mica-chlorite schist that is locally silicified and hornfelsed and Mesozoic or Paleozoic pyroxenite and hornblendite (Foster, 1976; DiMarchi, 1993). These rocks have been intruded by Tertiary or Mesozoic granitic rocks. Stream-sediment samples collected by WGM Inc. from the creeks draining the divide between Sam Patch Creek and Nugget Gulch contain between 25 and 32 ppb gold (DiMarchi, 1993). An anomalous soil sample with 85 ppb gold and a stream-sediment sample containing 1,081 ppb gold were collected by ASA Inc. Restricted zones of silicification and quartz-carbonate alteration are present, and pyrite is found in quartz veins and disseminated within folded layers of quartzite. There is abundant iron-oxide-stained soil with fragments of quartz-carbonate veining on ridge tops in the area, but without associated gold anomalies. There is a strong magnetic anomaly in the area of the 1,081-ppb gold sample, indicating the presence of a large, east-west-trending ultramafic body (WGM Inc., 1998 [DLR 98-12]). Two deposit models have been proposed for this occurrence. Copper-bearing calc-silicate rocks in the area suggest the potential for copper-gold skarns (DiMarchi, 1993). The presence of ultramafic rocks suggest the potential for Mother Lode-style, gold-quartz-carbonate vein mineralization (WGM Inc., 1998 [DLR 98-12]).
Stream -ediment samples were collected by WGM Inc. in 1990, from the creeks draining the divide between Sam Patch Creek and Nugget Gulch (DiMarchi, 1993). ASA Inc. collected stream and soil samples in the area in 1992. A geophysical survey was flown in the Nugget Gulch area in 1997 (WGM Inc., 1998 [DLR 98-12]).
Geologic map unit (-141.159080050759, 64.3182014126251)
Age of mineralization Paleozoic or younger.
Alteration of deposit There are restricted zones of silicification and quartz-carbonate alteration in the vicinity of this occurrence at the head of Nugget Gulch (DiMarchi, 1993).

Production and reserves

Workings or exploration Stream-sediment samples were collected by WGM Inc. in 1990, from the creeks draining the divide between Sam Patch Creek and Nugget Gulch (DiMarchi, 1993). ASA Inc. collected stream and soil samples in the area in 1992. A geophysical survey was flown in the Nugget Gulch area in 1997 (WGM Inc., 1998 [DLR 98-12]).
Indication of production None

Additional comments

This occurrence is located within Doyon, Ltd. selected or conveyed land. For more information contact Doyon, Ltd., Fairbanks, Alaska.

References

References

DiMarchi, J.J., 1993, 1992 annual report, reconnaissance program, Doyon option lands, v. 1, ASA Inc. report, Doyon, Ltd. Reports 93-168A and 93-44A. (Reports held by Doyon, Ltd., Fairbanks, Alaska).
WGM Inc., 1998, Ventures Resource Alaska projects, 1997 progress report, Champion property exploration: Doyon, Ltd. Report 98-12, 64 p. (Report held by Doyon, Ltd., Fairbanks, Alaska).
Reporters M.B. Werdon; R.L. Flynn
Last report date 5/1/2002