|Quadrangle map, 1:250,000-scale||CR|
|Quadrangle map, 1:63,360-scale||A-1|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||The Gladstone property extends over 4 claims. The site is at the northern workings at an elevation of about 150 feet. It is about 0.7 mile east of triangulation station Lancaster and about 0.5 mile west-northwest of the center of section 6, T. 77 S., R. 89 E. The property extends for about a half mile south-southwest to an open cut at an elevation of about 400 feet.|
Geologic descriptionAs originally described by Wright and Wright (1908), the Gladstone deposit consists of several brecciated quartz-calcite veins up to 6 feet thick, exposed over a distance of about a half mile. The veins contain pyrite and chalcopyrite; the host rock is mainly marble with schist layers that is part of the Wales Group of Late Proterozoic and Cambrian age (Eberlein and others, 1983; Brew, 1996). The property extended over four claims and included a tunnel and several open cuts. The deposit was examined by Maas and others (1991) and by Hedderly-Smith (1999 [Inventory]), who reinterpreted it as conformable gold- and copper-bearing breccia zones in carbonate rocks similar to deposits to the south in the Kael-7 Mile Trend (CR188). Maas and others (1991) examined the Gladstone adit, where a 10-foot-wide shear zone is exposed that contains quartz-marble breccia. The shear zone is up to 20 feet wide at the surface. Nine chip samples contained 19 to 190 parts per billion (ppb) gold and 1,742 parts per million (ppm) to 2.05 percent copper. A sample collected by Hedderly-Smith (1999 [Inventory]) across a 6-foot mineralized zone with about 5 percent pyrite and chalcopyrite contained 7,669 ppm copper and 11 ppb Au.
|Geologic map unit||(-132.072142043504, 55.225024951128)|
|Mineral deposit model||Probably a stratiform Au-Cu breccia zone in marble.|
|Age of mineralization||Younger than the Late Proterozoic or Cambrian host rock.|
|Alteration of deposit||If this deposit is similar to those in the Kael-7 Mile Trend (CR188), it is associated with silicification and dolomitization of the marble host rock.|
|Workings or exploration||Workings consists of a short adit and several open cuts over a distance of at least 0.5 mile.|
|Indication of production||None|
Brew, D.A., 1996, Geologic map of the Craig, Dixon Entrance, and parts of the Ketchikan and Prince Rupert quadrangles, southeastern Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-2319, 53 p., 1 sheet, scale 1:250,000.
Bufvers, John, 1967, History of mines and prospects, Ketchikan district, prior to 1952: Alaska Division of Mines and Minerals Special Report 1, 32 p.
Cobb, E. H., 1978, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Craig quadrangle, Alaska: U.S. Geological Survey Open-File Report 78-869, 262 p.
Eberlein, G.D., Churkin, Michael, Jr., Carter, Claire, Berg, H.C., and Ovenshine, A. T., 1983, Geology of the Craig quadrangle, Alaska: U.S. Geological Survey Open-File Report 83-91, 52 p.
Hedderly-Smith, D.A., 1992, Report of 1992 work in the Kael-Dolomi area-Sealaska minerals project: Sealaska Corporation, 60 p. (Unpublished report held by the Sealaska Corporation, Juneau, Alaska.)
Hedderly-Smith, D.A., 1993, Report of the 1992 field season-Sealaska minerals reconnaissance project: Sealaska Corporation, 60 p. (Unpublished report held by the Sealaska Corporation, Juneau, Alaska.)
Hedderly-Smith, D.A., 1993, Report of the 1992 work in the Brennan Bay-Kitkun Bay area-Sealaska minerals reconnaissance project: Sealaska Corporation, 24 p. (Unpublished report held by the Sealaska Corporation, Juneau, Alaska.)
Hedderly-Smith, D.A., 1999, Inventory of metallic mineral prospects, showings and anomalies on Sealaska lands, 1988 through 1998: Sealaska Corporation, Juneau, Alaska, 217 p. (internal report held by Sealaska Corporation, Juneau, Alaska).
Maas, K.M., Bittenbender, P E., and Still, J.C., 1995, Mineral investigations in the Ketchikan mining district, southeastern Alaska: U.S. Bureau of Mines Open-File Report 11-95, 606 p.
Maas, K.M., Still, J.C., and Bittenbender, P.E., 1992, Mineral investigations in the Ketchikan mining district, Alaska, 1991 - Prince of Wales Island and Vicinity: U.S. Bureau of Mines Open-File Report 81-92, 69 p., 1 sheet, scale 1:20.
Wright, F.E., and Wright, C.W., 1906, Lode mining in southeastern Alaska, in Brooks, A.H., 1906, Report on Progress of Investigations of Mineral Resources of Alaska in 1905: U.S. Geological Survey Bulletin 284, p. 30-54.
|Reporters||D.J. Grybeck (Applied Geology)|
|Last report date||5/1/2004|