|Quadrangle map, 1:250,000-scale||JU|
|Quadrangle map, 1:63,360-scale||C-4|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||The William Henry prospect is at an elevation of about 3,300 feet, on the west flank of William Henry Mountain and 2 miles west of Lynn Canal. It is located in the SW1/4 section 17, T. 36 S., R. 61 E. of the Copper River Meridian. The location is accurate within 1/4 mile.|
Geologic descriptionThe general area is underlain mainly by Silurian and Devonian graywacke and argillite and Middle Devonian carbonate, clastic and volcanic rocks (MacKevett and others, 1971; Brew and others, 1978). The country rocks at this prospect are Silurian graywacke and Devonian and Silurian greenstone intruded by small bodies of Cretaceous quartz monzonite and syenite (Clough and Redman, 1989). The quartz monzonite, which contains feldspars crystals up to 4 inches long, contains disseminated pyrite, and is highly altered to sericite, chlorite, epidote and clay minerals. The sedimentary and volcanic country rocks are silicified and contain disseminated pyrite. Carbonatite forms northwest-trending veins up to a foot thick. They are composed mostly of calcite and minor feldspar phenocrysts. The veins carry variable amounts of pyrite, galena, molybdenite, barite, rutile and biotite. Analyses of the veins show small amounts of rare-earth elements and elevated values of copper, zinc and gold. The area has been explored for uranium-thorium minerals (Clough and Redman, 1989).
|Geologic map unit||(-135.292218764749, 58.7442698879766)|
|Alteration of deposit||Pyrite-sericite-chlorite-epidote-clay alteration in quartz monzonite; silicification and pyritization of sedimentary and volcanic country rocks.|
|Workings or exploration||Surface sampling and mapping.|
|Indication of production||None|
Additional commentsThe Lucky Six (JU057) , William Henry (JU060), Kings View (JU058), Athero (JU062), and an unnamed occurrence (JU059) are on the flanks of William Henry Mountain and have been collectively referred to as the William Henry prospect or as being in the William Henry area.
Brew, D.A., Johnson, B.R., Grybeck, D., Griscom, A., Barnes, D.F., Kimball, A.L., Still, J.C., and Rataj, J.L., 1978, Mineral resources of the Glacier Bay National Monument Wilderness Study Area, Alaska: U.S. Geological Survey Open-File Report 78-494, 670 p., 7 sheets.
Clough, A.H., and Redman, E.C., 1989, Bureau of Mines mineral investigations in the Juneau mining district, Alaska, 1984-1988, Volume 2, Detailed mine, prospect, and mineral occurrence descriptions, Section C, West Lynn Canal subarea: U.S. Bureau of Mines of Mines Special Publication, 44 p.
Eakins, G.R., 1975, Uranium investigations in southeastern Alaska: Alaska Division of Geological and Geophysical Surveys Geologic Report 44, 62 p.
|Reporters||J.C. Barnett and L.D. Miller (Juneau, Alaska )|
|Last report date||12/15/2001|