Breen East (Hobson)

Prospect, Active?

Commodities and mineralogy

Main commodities Au
Other commodities Sb
Ore minerals arsenopyrite; gold; pyrite; pyrrhotite; stibnite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale NM
Quadrangle map, 1:63,360-scale D-1
Latitude 64.7658
Longitude -165.2959
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Breen East prospect includes two patented claims, Hobson Gold Lode and the adjacent Great American Lode. These are in the south-central part of section 26, T. 8 S., R. 33 W., Kateel River Meridian. The claims are on the top of the ridge that separates Hobson Creek from upper Manila Creek. Discovery trenches in the northeast part of the Hobson Gold Lode are about at an elevation of 1,600 feet. The location given is near the center end line that separates the two claims; it is within about 500 feet of the coordinates. The location of the discovery cuts on the Hobson Gold Lode claim is about at the site of locality 27 of Hummel (1962, MF-248), who, followed by Cobb (1972 [MF 463], 1978 [OFR 78-93]), appears to have mislocated the Breen East prospect.

Geologic setting

Geologic description

The Breen East prospect includes two claims patented in 1924, the Hobson Gold Lode and the adjacent Great American Lode. Hummel reported this to be an iron sulfide occurrence that may include arsenopyrite, pyrite, and, in some cases, pyrrhotite. The claims are immediately to the east of the northeast most Sliscovich group of patented claims (NM086). The Breen East claims lie along a steep northeast-trending fault mapped by Hummel (1962, location 27 [MF 248]). Bundtzen and others (1994) show the same northeast-trending fault as a lineament that passes northerly into a fault. The country rock is interlayered calcareous schist, quartz-muscovite schist, and lesser amounts of marble, schistose marble and black quartz schist. Part of the area is underlain by a metagranodiorite (Hummel, 1962 [MF 248]) that approximately corresponds to a muscovite-bearing felsic metavolcanic schist mapped by Bundtzen and others (1994).
Geologic map unit (-165.298520271794, 64.7650406031773)
Mineral deposit model Sulfide-bearing quartz veins? in metasedimentary rocks.

Production and reserves

Workings or exploration Workings at the time of the patent application included six shafts, six surface cuts, and two discovery locations. The two claims were patented in 1924; there has been no recent exploration.
Indication of production None