This site is located on land patented by, or interim-conveyed to, the Aleut Corporation.
Location: This prospect is at an elevation of about 300 feet, approximately 2 miles south of the town of Sand Point (Berg and Cobb, 1967, locality 6; Cobb, 1972 [MF 433], locality 3; MacKevett and Holloway, 1977, locality 3; Wilson and others, 1988, locality 3). The location is accurate.
Geology: The rocks at this prospect are the Eocene to Oligocene Popof volcanic rocks (Wilson and others, 1995). At this locality they consist mostly of basalt flows and tuffs. The names Herman Lode and Trench refer to prospects explored by several adits, pits, and a trench in the early 1900's. A mineralized zone 5 to 10 feet wide was reported to contain free gold (Atwood, 1909). The name Centennial was given to a gold deposit discovered in the same area in 1987 by Battle Mountain Exploration Company. The Centennial deposit is a large, low grade, disseminated gold lode. The country rocks consist of basalt flows, plugs, dikes, tuffs, and epiclastic deposits that overlie a basement sedimentary complex. The main mineralized zone occurs in a window eroded through a basalt flow. The mineralization is thought to be controlled in part by a plug margin, and in part by north-northeast-trending high-angle faults and fracture zones from which mineralizing fluids spread out into surrounding permeable rock (Ellis and Harris, 1989). The gold is disseminated in the matrix of the basaltic tuffs and also occurs in fractures and veins that cut the flows. The distribution of the mineralization seems to have a lower limit at 240 to 400 feet above the sedimentary basement complex. The gold is free and occurs in the plus-25-micron range (Ellis and Harris, 1989). Silver, mercury, and arsenic values are associated with the gold. The mineralization is accompanied by enrichment in silica and potassium, as shown by the presence of quartz, sericite, and adularia. Quartz and quartz-calcite veins and veinlets containing galena, sphalerite, pyrite, and some chalcopyrite were cut in some of the drill holes. Their relationship to the gold mineralization is not known. In sea cliffs due south of the Centennial deposit, a zone of north-striking quartz-sulfide veins cuts tuffs and overlying flows. These veins may occupy the same structures that control the mineralization at the Centennial deposit. At the base of the cliff the vein zone is 10.5 feet wide and consists of five sulfide-bearing veins. At 175 feet vertically above the base, the zone is 50 feet wide and consists of 12 narrow, poorly mineralized veins. In the early 1900's a short adit was driven at the base of the zone. No assays of interest from this area were reported by Battle Mountain Exploration Company.
Workings: In the early 1900's the prospect area was explored by tunnels, trenches, and pits. Battle Mountain Exploration Company evaluated the area in the late 1980s and carried out detailed mapping and sampling programs. Their exploration also included drilling 484 auger holes and 59 diamond drill holes, 7,275 feet of trenching, and magnetic and VLF-EM surveys.
Age: Eocene or younger.
Alteration: The rocks in the area exhibit pervasive propylitic alteration. The mineralization is accompanied by enrichment in silica and potassium, resulting in deposition of adularia, sericite, and quartz. Argillic alteration is locally present. Calcite stockwork veining is widespread.
Reserves: The resource is estimated at 4.8 million tons grading 0.042 ounce of gold per ton within 175 feet of the surface (Ellis and Harris, 1989).

Commodities (Major) - Ag, Au; (Minor) - As, Cu, Hg, Pb, Zn
Development Status: None
Deposit Model: Volcanic-hosted disseminated gold deposit

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Commodity List

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Mineral List

7 valid minerals.