| Quadrangle map, 1:250,000-scale | FB |
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| Quadrangle map, 1:63,360-scale | D-3 |
| Latitude | 64.869 |
| Longitude | -148.006 |
| Nearby scientific data | Find additional scientific data near this location |
| Location and accuracy | The Irad prospect is near the head of the east fork of Eva Creek at an elevation of about 1,000 feet. It is about 1.5 miles north-northeast of the town of Ester in the SW1/4 sec. 32, T. 1 N., R. 2 W., Fairbanks Meridian. |
Geologic descriptionThe rocks in the vicinity have been mapped as a bleached feldspathic schist unit of the Fairbanks Schist by Newberry and others (1996). However, this rock type was not seen in a trench excavated by Placer Dome Exploration in 1997; the rock exposed in these trenches appears to be more similar to the Fairbanks Schist described elsewhere as quartz-muscovite schist (Rogers and others, 1998). In 1990 to 1992, American Copper and Nickel Co. (ACNC) collected soil samples from the surrounding area. In 1998, Placer Dome Exploration conducted a soil program that identified a 300-meter by 100-meter soil anomaly of gold with upper values that varied from 500 to 1,000 ppb gold (Roger and others, 1998). The anomalous soils occur near the intersection of a northeast and northwest trend of anomalous soils that cross Ester Dome. The northeast trend has been interpreted to be related to a high-angle fault that transects the McQueen and Rhyolite prospects (FB011 and FB016, respectively) (Rogers and others, 1998). Follow-up trenching produced discouraging results; no sample containing more than 0.4 ppm gold. A magnetic high was identified over the prospect in both State of Alaska and ACNC airborne geophysical surveys. A ground-based geophysical survey conducted by Placer Dome Exploration gave similar results (Rogers and others, 1998). | |
| Geologic map unit | (-148.008429672176, 64.8685636567255) |
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| Mineral deposit model | Schist-hosted gold-quartz vein |
| Workings or exploration | Several old prospect pits were identified in the area. In 1990 to 1992, American Copper and Nickel Co. (ACNC) collected soil samples from the surrounding area. In 1998, Placer Dome Exploration conducted a soil program that identified a 300-meter by 100-meter anomaly in gold. Follow up work consisted of trench excavation. The prospect was then covered with a ground-based magnetic geophysical survey (Rogers and others, 1998). Airborne geophysics were conducted both by the State of Alaska and ACNC. |
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| Indication of production | None |
| MRDS Number | 10307438 |
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ReferencesRogers, J.A., McCoy, D. T., Nerup, M., Yuengling, K., Bean, K., Cameron, C., Grahm, G., Frantz, P., and Athey, J., 1998, Placer Dome-Silverado lease, 1998 annual report for Ester Dome: 68 p. (Report held by Range Minerals, Inc., North Pole, Alaska 99705.)
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| Reporters | J.R. Guidetti Schaefer and C.J. Freeman (Avalon Development Corporation) |
| Last report date | 7/31/2001 |