Unnamed (west end of 'Mariposite Ridge')

Occurrence, Active

Commodities and mineralogy

Main commodities Ag; Au; Pb; Zn
Other commodities Ba
Gangue minerals calcite; mariposite; quartz

Geographic location

Quadrangle map, 1:250,000-scale JU
Quadrangle map, 1:63,360-scale A-3
Latitude 58.1018
Longitude -134.6771
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is at an elevation of approximately 2,800 feet on the west end of a feature locally called Mariposite Ridge. It is 3 miles southeast of Hawk Inlet docks and transfer facility, 5 miles west of Eagle Peak, and 2 miles northwest of the Greens Creek Mine (JU253), in the NW1/4SE1/4 section 31, T. 43 S., R. 66 E. of the Copper River Meridian. The location is accurate within 1/8 mile. The occurrence may be at the west edge of the Mammoth prospect (JU248).

Geologic setting

Geologic description

Wells and others (1986) describe this occurrence as quartz veins in a shear zone in mariposite-bearing dolomite. Nearby metavolcanic rocks are also sheared and veined with quartz. A sample of vein material collected in 1983 contained 0.73 percent lead, 0.3 percent zinc and 0.25 ppm silver. A sample of quartz-rich metavolcanic rock contained 0.5 percent barite and traces of arsenic, silver and gold (Wells and others, 1986). The rocks in the general area are mainly Ordovician and Devonian to Triassic, clastic units, mafic-intermediate volcanic rocks, and subordinate limestone. The bedded rocks are intruded and locally metamorphosed by Cretaceous granodiorite (Gehrels and Berg, 1994).
Geologic map unit (-134.678881021528, 58.1014645605915)

Production and reserves

Workings or exploration Surface sampling only.
Indication of production None

References

MRDS Number A012086

References

Gehrels, G.E., and Berg, H.C., 1994, Geology of southeastern Alaska, in Plafker, George, and Berg, H. C., eds., The geology of Alaska: Geological Society of America, DNAG, The geology of North America, Vol. G-1, p. 451-467.
Reporters J.C. Barnett and L.D. Miller (Juneau, Alaska )
Last report date 12/15/2001