Preliminary geologic and rock-chip geochemical data from drill core and trenches at the Shumagin gold deposit, Unga Island, Alaska

Abstract

Preliminary geologic and rock-chip geochemical data from drill core and trenches at the Shumagin gold deposit,

Interpretation of exploration geochemical data for the Mount Katmai Quadrangle and adjacent parts of the Afognak and Naknek quadrangles, Alaska

“…White and Queen (1989) reported results from a drilling program indicating reserves of270,000 tonnes of gold ore at 16.8 g/tonne gold from a quartz vein ranging in width from 1 to 15 m over a length of 370 m. The ore zone is a pyrite-bearing quartz vein that contains Au, Ag, Te, Pb, Zn, and Mn at anomalous concentrations. Anomalous concentrations of arsenic and copper in altered rock are detected in some places in the ore zone; mercury forms a 75-m-wide halo surrounding the deposit.…”

Maps showing the resource assessment of the Port Moller, Stepovak Bay, and Simeonof Island quadrangles, Alaska Peninsula with a section on geology of the Pyramid porphyry copper deposit, Alaska Peninsula, Alaska

“…Renewed exploration and development activity at the Alaska-Apollo Mine beginning in the 1980's resulted in the blocking out of reserves at the Alaska-Apollo and Sitka Mines and a major discovery at the turn of the 20th century Shumagin prospect (see section B and White and Queen, 1989).…”

“…The Shumagin deposit (White and Queen, 1989) and, secondarily, the Alaska-Apollo deposit are most useful in defining this model. We realized in the application of the deposit models to the Unga and Popof Islands and the mainland parts of the study area, that the model of necessity varied.…”

“…These are the porphyry copper, epithermal gold, and polymetallic vein models. Two mineral deposits in the study area, the Pyramid porphyry copper deposit (section A) and the Shumagin epithermal gold vein deposit White and Queen, 1989; and section B, this report) were used as type examples for the mineral resource assessment. The characteristics of these deposits also help us "finetune" the mineral deposit models to the Port Moller study area.…”

“…The epithermal gold vein model was developed by W.H. White based on studies of the Shumagin deposit (White and Queen, 1989; section B this report, and unpublished data). These derivative maps used thresholds calculated for rock-type groups, rather than the thresholds derived from the overall data set as used for other maps.…”