New Boston

Prospect, Inactive

Alternative names

Eagle Creek

Commodities and mineralogy

Main commodities Cu; Pb; Zn
Other commodities Ag; Au
Ore minerals chalcopyrite; galena; pyrite; sphalerite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale JU
Quadrangle map, 1:63,360-scale B-2
Latitude 58.3046
Longitude -134.466
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is at an elevation of approximately 500 feet. It is on the south side of Eagle Creek on northeastern Douglas Island, about 1.5 miles northwest of West Juneau, in about the center of the N1/2 section 21, T. 41 S., R. 67 E. of the Copper River Meridian. The location is accurate.

Geologic setting

Geologic description

The rocks in the area are Upper Jurassic or Cretaceous marine argillite and graywacke, interbedded with andesite or basalt (Brew and Ford, 1985). The bedded rocks are regionally metamorphosed to prehnite-pumpellyite or greenschist grade, and cut by diorite or gabbro dikes and sills.
The deposit was discovered in 1888 and developed by a 1,040-foot adit and a 415-foot adit. The facilities included an 80-stamp mill, a tram, wharfs, and dock facilities. The recorded production is 2 ounces of gold (Redman and others, 1989). The rocks at the prospect are black phyllite, felsic phyllite, greenstone, and very-fine-grained augite metagabbro or diabase. The strata strike northwest and dip moderately northeast. The felsic phyllite is composed of quartz, muscovite, and feldspar. The unit is several hundred feet thick; has 1 to 3 percent disseminated pyrite, and is cut by small quartz veins with sphalerite, galena, and chalcopyrite, and traces of gold and silver. The U.S. Bureau of Mines suggests that this prospect is similar to the Alaska Treasure massive sulfide deposit (JU228) (Redman and others, 1989; Wells and others, 1986).
Geologic map unit (-134.467773688749, 58.3042725509318)

Production and reserves

Workings or exploration The deposit was discovered in 1888 and developed by a 1,040-foot adit and a 415-foot adit. The facilities included an 80-stamp mill, a tram, wharfs, and dock facilities.
Indication of production None
Production notes Recorded production was 2 ounces of gold.

References