Eureka Gulch

Occurrence, Inactive

Commodities and mineralogy

Main commodities Ag; Au; Cu; Pb; Zn
Ore minerals chalcopyrite; galena; sphalerite

Geographic location

Quadrangle map, 1:250,000-scale NB
Quadrangle map, 1:63,360-scale A-1
Latitude 62.0566
Longitude -141.0054
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is at the head of Eureka Gulch, a south tributary to Lamb Creek. The occurrence is at an elevation of about 4,500 feet, near the northeast corner of section 9, T. 3 N., R. 24 E. of the Copper River Meridian. This is National Park Service locality WRST-90 (unpublished data) and the coordinates of this occurrence were provided by the National Park Service.

Geologic setting

Geologic description

An unpublished National Park Service map and accompanying database identify this as a gold, copper, lead and zinc prospect. It appears to be a prospect described by Moffit and Knopf (1909) at the head of Eureka Creek, near the international boundary. A number of quartz veins, 4 to 12 feet thick, contain a small amount of chalcopyrite and locally are copper-stained. At least one quartz vein, localized in a shear zone up to 8 feet wide, contains argentiferous galena and sphalerite. This deposit was explored by a 60-foot long adit by 1909 (Moffit and Knopf, 1909). A major fault that trends along Eureka Creek juxtaposes upper Paleozoic volcanic rocks to the south against Jurassic or Cretaceous siliciclastic rocks to the north. In this area, the bedded rocks are locally intruded by dikes and small irregular bodies of Cretaceous or Tertiary, porphyritic diorite and mafic diorite (Richter and others, 1973).
Geologic map unit (-141.007525930686, 62.0562767362781)
Mineral deposit model Polymetallic veins? (Cox and Singer, 1986; model 22c)
Mineral deposit model number 22c
Age of mineralization Cretaceous or Tertiary? Mineralization may be related to emplacement of the Cretaceous or Tertiary intrusive rocks.
Alteration of deposit Silicification and oxidation.

Production and reserves

Workings or exploration Surface prospecting has been done in this area and at least one 60-foot- long adit is reported to have explored a quartz vein (Moffit and Knopf, 1909).
Indication of production Undetermined

Additional comments

The prospect is in the Wrangell-St. Elias National Preserve.