Midnight Sun

Prospect, Undetermined

Commodities and mineralogy

Main commodities Au
Ore minerals gold; pyrite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale CR
Quadrangle map, 1:63,360-scale C-1
Latitude 55.65577
Longitude -132.01838
Nearby scientific data Find additional scientific data near this location
Location and accuracy In their text, Wright and Wright (1908) locate this prospect at an elevation of about 560 feet, about one-half mile west of the upper workings of the Gold Standard Mine (CR081). However, their small-scale, somewhat generalized map shows it about one-half mile northwest of the upper workings of the Gold Standard Mine; this would would place it at a considerable higher elevation of about 1,000 feet or more. For this record, the site follows their map and places the prospect about 0.5 mile east of the center of section 2, T. 72 S., R. 87 E. The location is probably accurate to within 0.5 mile.

Geologic setting

Geologic description

The only working at the Midnight Sun prospect is a 15-foot open cut (Wright and Wright, 1908). A quartz vein 6 inches to 2 feet thick, that strikes N80W and dips 30N, cuts greenstone and greenschist. The vein and host rocks are cut by numerous faults that offset the vein. The vein includes fragments of wall rock, and minor pyrite and free gold. Apparently there has been no work on the prospect since 1908. The rocks in the area consist of metamorphosed andesite, basalt, agglomerate, and tuff, and minor flysch, shale, and phyllite. Eberlein and others (1983) and Brew (1996) consider them to be Paleozoic or Mesozoic in age; Gehrels and Berg (1992) tentatively mapped them as Jurassic or Cretaceous.
Geologic map unit (-132.020064094508, 55.6554075376021)
Mineral deposit model Low-sulfide gold-quartz vein (Cox and Singer, 1986; model 36a).
Mineral deposit model number 36a
Age of mineralization The quartz veins cut country rocks that may be as young as Cretaceous or as old as Paleozoic.

Production and reserves

Workings or exploration The only working is a 15-foot open cut.
Indication of production None

References