Kuiu

Mine, Undetermined

Commodities and mineralogy

Main commodities Ag; Au; Pb; Zn
Ore minerals galena; sphalerite
Gangue minerals limestone

Geographic location

Quadrangle map, 1:250,000-scale PA
Quadrangle map, 1:63,360-scale D-1
Latitude 56.89795
Longitude -134.10656
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Kuiu Mine is at en elevation of about 80 feet, 800 feet inland, and about 0.8 mile east of hill 815. It is about in the center of section 29, T. 57 S., R. 72 E.

Geologic setting

Geologic description

This mine is one of a group of similar deposits (PA021 to PA031) that are scattered along the south shore of Saginaw Bay, on the peninsula north of Saginaw Bay, and on the Keku Islands. They occur in a heterogeneous section of unmetamorphosed volcanic, carbonate, and clastic rocks that vary in age from Silurian to Triassic (Muffler, 1967). The mineralization generally consists of veins, veinlets, and irregular pods that contain base metals and barite (Still and others, 2002). There are no plutonic rocks in the immediate vicinity; however, the sedimentary rocks are cut by scattered gabbro dikes. The origin of the deposits is uncertain although most appear to be epigenetic. Various origins have been proposed including that they are remobilized massive-sulfide deposits, that they are related to a buried intrusive, or that they are Mississippi-Valley-type deposits.
The deposit at the Kuiu Mine was known prior to 1937 when 32 lode claims were staked on it. They remained active until at least 1951 (Still and others, 2002). In 1937 and 1938, 150 to 200 tons of ore were removed from an open cut and stacked nearby (Roehm, 1938 [PE 116-1]). By 1946 the property had been explored by a 55-foot adit with a winze and a 25-foot sublevel (Roehm, 1946 [PE 116-4]). By 1946, the workings below the adit were flooded and that is no indication that any significant mineralization was found in the underground workings. In addition, 14 diamond drill holes were put down on the property in 1946 but apparently no mineralization was encountered in them.
The rocks at the Kuiu Mine are felsic volcanics and agglomerates overlain by dolomitic limestone, all part of the Keku Volcanics (Roehm, 1946 [PE 116-4]; Muffler, 1967). The deposit consists of small pods and irregular masses of sphalerite and galena that replace limestone. The largest orebody, the orebody mined in a surface pit in 1937 and 1938, was about 30 feet by 40 feet in section and about 200 feet in length. The ore from it was said by the owners to contain 4-18 percent zinc, 5-6 percent lead, a trace to 0.07 ounce of gold per ton, and 0.6 to 5.9 ounces of silver per ton (Thorne, 1948). However, samples collected by Roehm (1938 [Supplement]) contained only 0.18 to 0.29 percent zinc and a grab sample of the ore pile contained only 2.75 percent zinc. Still and others (2002) sampled a small surface cut with small pods of sphalerite and galena that replace dolomite. The samples contained 313.6 parts per million silver to 21.72 ounces of silver per ton, 10.31 to 20.54 percent lead, and 7.7 to 13.4 percent zinc.
Geologic map unit (-134.108281316913, 56.8976154536683)
Mineral deposit model Lead-zinc replacement deposit in dolomitic limestone.
Age of mineralization Galena and sphalerite replace Triassic limestone.

Production and reserves

Workings or exploration The deposit at the Kuiu Mine was known prior to 1937 when 32 lode claims were staked on it. They remained active until at least 1951 (Still and others, 2002). In 1937 and 1938, 150 to 200 tons of ore were removed from an open cut and stacked nearby (Roehm, 1938 [PE 116-1]). By 1946 the property had been explored by a 55-foot adit with a winze and a 25-foot sublevel (Roehm, 1946 [PE 116-4]). By 1946, the workings below the adit were flooded and that is no indication that any significant mineralization was found in the underground workings. In addition, 14 diamond drill holes were put down on the property in 1946 but apparently no mineralization was encountered in them.
Indication of production Yes; small
Reserve estimates None.
Production notes In 1937 and 1938, 150 to 200 tons of ore were removed from an open cut and stacked nearby (Roehm, 1938 [PE 116-1]).

Additional comments

The prospect is on land that has been selected by the Sealaska Native Corporation and the Kake Tribal Corporation for patent.
MAS number: 0021160003.

References

References

Roehm, J.C., 1938, Supplementary report to preliminary report of Keku Group of claims, Kuiu Island, Alaska: Alaska Division of Geological and Geophysical Surveys Supplement to Preliminary Report, 2 p.
Roehm, J.C., 1946, Report of investigations at Kuiu Zinc Mines, Inc., Keku Straits, Kuiu Island, Alaska: Attached to Alaska Division of Geological and Geophysical Surveys, Prospect Evaluation PE 116-4, 31 p.
Still, J.C., Bittenbender, P.E., Bean, K.W., and Gensler, E.G., 2002 Mineral assessment of the Stikine area, central Southeast Alaska: U.S. Bureau of Land Management Technical Report 51, 560 p.
Thorne, R.L., 1948, Hungerford prospect, Kuiu Island: Unpublished U.S. Bureau of Mines Memorandum, 2 p. (On file at the Juneau Mineral Center, U.S. Bureau of Land Management, Juneau, Alaska.)
Reporters Donald J. Grybeck (U.S. Geological Survey)
Last report date 2-Jan-05