Unnamed (east of Upper Marten Lake)

Occurrence, Probably inactive

Commodities and mineralogy

Main commodities Ag; Au; Pb
Ore minerals pyrite; pyrrhotite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale BC
Quadrangle map, 1:63,360-scale B-6
Latitude 56.2889
Longitude -131.7921
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is in a saddle at an elevation of 2,600 feet; it is about 1.1 mile east-southeast of the southeast end of Upper Marten Lake near the center of section 26, T. 64 S., R. 86 E., of the Copper River Meridian. The location is accurate.

Geologic setting

Geologic description

This occurrence was first described by Still and others (2002) in an area with little previous indication of mineralization. It is along a fault zone that strikes 330 degrees and dips 75 degrees to the northeast. The fault cuts Mesozoic and/or Paleozoic schist and paragneiss near the contact with Cretaceous diorite (Elliot and Koch, 1981). The occurrence is about 2 miles west of the Coast Range megalineament (Brew and Ford, 1978), and the 'Great Tonalite Sill' (Brew and Morrell, 1983). Quartz stringers and clay gouge are common in the fault zone. Some of the quartz stringers contain pyrite, pyrrhotite, and other sulfides. Four samples of iron-stained quartz were collected along the fault; one contained 475 parts per billion gold, 86.9 part per million (ppm) silver, and 1,218 ppm lead.
Another quartz vein about 0.2 to 1 foot thick about 2 miles north of the main occurrence contains only minor pyrite and assayed 517 ppb gold.
Geologic map unit (-131.793787403184, 56.2885516678091)
Mineral deposit model Gold-quartz veinlets along a regional fault.
Alteration of deposit No information other than along a fault zone with clay gouge.

Production and reserves

Workings or exploration Only a few samples collected by Still and others (2002) during a regional mineral assessment by the Bureau of Land Management.
Indication of production None

References

References

Brew, D.A., and Morrell, R.P., 1983, Intrusive rocks and pluton belts of southeastern Alaska, Geologic Society of America Memoir, 159, p. 171-193.
Still, J.C., Bittenbender, P.E., Bean, K.W., and Gensler, E.G., 2002, Mineral assessment of the Stikine area, central southeast Alaska: Bureau of Land Management Technical Report 51, 560 p.
Reporters D.J. Grybeck (Port Ludlow, WA)
Last report date 3/4/2008