Beauty prospect (Triangle No. 2; Home; Welcome prospects), Dolomi Mountain, Prince of Wales Island, Ketchikan District, Prince of Wales-Outer Ketchikan Borough, Alaska, USA

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Location: This site is located 1.9 km (6,300 feet) ESE of Dolomi Mountain (coordinates of record), and about 0.3 mile S of James Lake and Williams Lake, 2 small lakes, about 0.6 mile northeast of the center of section 6, T78S, R89E. It includes four prospects/claims about a half mile N of Dolomi. They were originally described between 1902 and 1908 but not since, and they probably have been incorporated into one or more of the nearby properties. The Beauty claim is the only one that can be confidently located, and that site (the one used for this record) is based only on a small-scale map by Wright and Wright (1908, figure 18). The other three claims or prospects adjoin, or probably are within 0.3 mile of, the Beauty claim.

Geology: This site includes 4 similar deposits (Brooks, 1902; Wright and Wright, 1908). The deposit on the Beauty claim is in marble and consists of a quartz vein 12-18 inches thick that strikes N20W and dips 30SW. The vein contains chalcopyrite and tetrahedrite, and samples assayed up to $600 per ton in silver and $20 per ton in gold (at $20.67 per ounce). Another vein on the same claim strikes N20E and dips 20SE. The Beauty claim was explored by 2 shafts 45 feet deep and a drift that connected them. The Home deposit is a quartz vein up to 2 feet thick that cuts fractured marble. The vein contains pyrite and tetrahedrite. At the Triangle #2 claim, a quartz-calcite vein 4 to 5 feet thick is exposed in a pit. The vein strikes N40W and dips 35NE. Samples assayed as high as $40 per ton (presumably in gold and silver). On the Welcome claim, a mineralized shear zone at the contact of schist and marble was said to contain free gold. Most, if not all four, of these claims/prospects are probably included in what Herreid (1967) calls 'Prospects east of Amazon Lake,' 'Prospects east of central Amazon Lake,' and 'Prospects west of Amazon and James Lake.' However, his prospect names cannot be correlated with the names of the prospects at this site in the older literature. As in the old reports, Herreid repeatedly mentions the occurrence of tetrahedrite in many of the deposits in this area. The geology of the Dolomi area is dominated by an arcuate, generally north-trending, fault system and by a large dome centered over the eastern third of Paul Lake (Herreid, 1967). The Wales Group country rocks consist chiefly of several marble layers 200 to 1300 feet thick, interbedded with calcareous chlorite schist and marble.

Workings: Explored by pits and several shallow shafts with some minor underground workings.

Age: Veins are younger than the Late Proterozoic or Cambrian host rocks.

Commodities (Major) - Ag, Au

Development Status: None

Deposit Model: Low-sulfide gold-quartz vein (Cox and Singer, 1986; model 36a).

Mineral List

Calcite Chalcopyrite

Gold Quartz

Tetrahedrite

5 entries listed. 5 valid minerals.

References