Blue Bucket

Prospect, Undetermined

Alternative names

Beach Adit

Commodities and mineralogy

Main commodities Au
Other commodities Cu
Ore minerals chalcopyrite; gold; pyrite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale KC
Quadrangle map, 1:63,360-scale C-6
Latitude 55.593
Longitude -131.966
Nearby scientific data Find additional scientific data near this location
Location and accuracy
This prospect is on the northeast shore of Smugglers Cove, about 0.5 mile southeast of the head of the falls at the mouth of Falls Creek. The site is in section 29, T. 72 S., R. 88 E., of the Copper River Meridian. It corresponds to loc. 258 in Maas and others (1995, fig. 46), and to loc. 39 in Elliott and others (1978).The location is accurate within 0.1 mile.
Also see Additional comments.

Geologic setting

Geologic description

The country rocks near this site include gray and green phyllite and semischist derived from intertonguing flysch and andesitic and basaltic volcanic rocks (Berg and others, 1988, p. 17-20); and gray felsic schist possibly derived from silicic tuff (Maas and others, 1995, p. 183 and fig. 46). Near Smugglers Cove, the bedded rocks are intruded by diorite that may be transitional to the andesitic and basaltic volcanic rocks. The bedded and intrusive rocks were regionally metamorphosed to greenschist grade in Late Cretaceous time (Brew, 1996, p. 27). Their premetamorphic age is uncertain. Berg and others (1988, p. 17) note that the intertonguing flysch and volcanic rocks closely resemble Upper Jurassic to mid-Cretaceous marine strata nearby on Gravina Island.
The deposit consists of an auriferous, pyrite- and chalcopyrite-bearing quartz fissure vein in pyritic chlorite and sericite schists (Wright and Wright, 1908, p. 156-157; Maas and others, 1995, p. 184-189). The vein crosscuts the foliation of the schists, which strike N38W and dip 65 NE. The deposit was explored in the early 1900s by a 16-foot adit.
Maas and others (1995, p. 184-189, fig. 46, and tables 25 and 26) suggest that the Blue Bucket deposit may be part of a belt of exhalative volcanogenic gold deposits (KC035) that extends along the northeast shore of Smugglers Cove and also includes the Mary T. (KC036) and U.S. (KC037) deposits. The average metal contents of their samples of the Blue Bucket deposit are 1.68 ppm Au, 2.3 ppm Ag, 4367 ppm Cu, 10.2 ppm Pb, and 97 ppm Zn. The high Cu assay indicates that the deposit contains chalcopyrite in addition to the auriferous pyrite.
The age of the postulated exhalative deposits is unknown. The quartz fissure vein, which crosscuts the foliation of the schist, probably is Late Cretaceous (see KC028).
Geologic map unit (-131.967682751653, 55.5926374470435)
Mineral deposit model Low-sulfide gold-quartz veins (Cox and Singer, 1986; model 36a)
Mineral deposit model number 36a
Age of mineralization The auriferous quartz fissure vein probably is Late Cretaceous.

Production and reserves

Workings or exploration The deposit was explored in the early 1900s by a 16-foot adit. The Blue Bucket prospect area was diamond-drilled by private interests in 1989 (Maas and others, 1995, p. 191). Five holes were drilled with a cumulative length of about 1060 feet. Other private exploration in the Smugglers Cove area has included soil geochemical testing, and VLF and magnetometer surveys. These surveys identified large inferred zones of gold-bearing strata. One such zone is 14-18 feet wide and at least 114 feet long, and is estimated to average 3.4 ppm Au. This zone is part of a larger zone 36 feet wide and at least 456 feet long that is estimated to average 1.7 ppm Au.
Indication of production None
Reserve estimates Exploration surveys in the Blue Bucket prospect area by private interests have identified large inferred zones of gold-bearing strata (Maas and others, 1995, p. 191). One such zone is 14-18 feet wide and at least 114 feet long, and is estimated to average 3.4 ppm Au. This zone is part of a larger zone 36 feet wide and at least 456 feet long that is estimated to average 1.7 ppm Au.

Additional comments

The Blue Bucket prospect is also known as the Beach Adit prospect (Maas and others, 1995, p. 191).

References