Unnamed (north of Mount Hamilton)

Prospect, Undetermined

Commodities and mineralogy

Main commodities Au
Ore minerals gold; pyrite
Gangue minerals calcite; chlorite; iron oxide; quartz

Geographic location

Quadrangle map, 1:250,000-scale RM
Quadrangle map, 1:63,360-scale A-3
Latitude 61.222
Longitude -159.794
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is on the crest of a ridge north of Mount Hamilton and east of Ophir Creek, near a local summit with an elevation of 1,310 feet. The map site is at the northeast corner of sec. 14, T. 13 N., R. 59 W., of the Seward Meridian. This is locality 1 of Frost (1990). The location is probably accurate within one-quarter mile.

Geologic setting

Geologic description

Frost (1990) described gold- and pyrite-bearing quartz veins cutting sericitized andesite and volcaniclastic hornfels at this location. The veins are vuggy and contain euhedral quartz prisms extending into open spaces. Other gangue minerals in the iron oxide-stained veins are commonly calcite and chlorite. A quartz vein from this prospect contained 12 ppm gold and 10 ppm silver (Frost, 1990, sample locality 1). Bedrock in the area includes thermally metamorphosed Jurassic volcanic or volcaniclastic rocks (Box and others, 1993). The thermal metamorphism is caused by a large mid-Cretaceous granitic pluton exposed to the west of Ophir Creek.
Geologic map unit (-159.796318893179, 61.2212708412614)
Mineral deposit model Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a)
Mineral deposit model number 36a
Age of mineralization Cretaceous or Tertiary. The gold-bearing quartz veins crosscut hornfels developed in country rocks around a mid-Cretaceous granitic pluton.
Alteration of deposit Sericitization and silicification.

Production and reserves

Workings or exploration Prospecting pit(s) are present at this location.
Indication of production None