|Quadrangle map, 1:250,000-scale||SK|
|Quadrangle map, 1:63,360-scale||A-1|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This occurrence is in beach cliffs on the western coast of Kataguni Island about 0.2 miles from the southern tip of the island. It is shown as localities 48 to 52 in Still (1988).|
Still (1988) indicates that, 'Mineralization is located in metabasalt sea cliffs up to 50 feet high that contain numerous narrow shear zones at various orientations. Some of the shears are silicified and contain copper or copper-zinc mineralization. Samples collected from these 0.2- to 1.4-foot-thick shear-controlled veins contain up to 2.54 ppm gold, 22.5 ppm silver, 6.9% copper, and 2.14% zinc.'Plafker, Hudson, and Silberling (1979) and Plafker and Hudson (1980) note that on the Chilkat Peninsula the same metabasalts are vesicular and/or amygdaloidal and that well-developed pillow textures are locally present. Based in part on fossil evidence that supports a Late Triassic (Karnian) age, they suggest that the metavolcanics and carbonates may correlate with similar rocks of the Wrangellia terrane. The age of the mineralization is not well established, but can be no older than the Late Triassic age of the host rocks. If the shearing and mineralization are both related to the nearby Chilkat Fault, then the age of the mineralization is probably Tertiary or younger as most movement on the Chilkat Fault has been post-Mesozoic (Lanphere, 1978).
|Geologic map unit||(-135.251823390086, 59.0096710969596)|
|Mineral deposit model||Au-Ag-Cu-Zn in shear zones in metabasalt.|
|Age of mineralization||The age of the mineralization is not well established, but must be no older than the Late Triassic (Karnian) age of the metabasalts that host the deposit (Plafker, Hudson and Silberling, 1979; Plafker and Hudson, 1980). If the shearing and mineralization are both related to the nearby Chatham Strait Fault, then the age of the mineralization is probably Tertiary or younger as most movement on the Chilkat Fault has been post-Mesozoic (Lanphere, 1978).|
|Alteration of deposit||Epidotization, silicification.|
|Indication of production||None|
Additional commentsThis occurrence is within the Chilkat Islands, State Marine Park.
Lanphere, M.A., 1978, Displacement history of the Denali fault system, Alaska and Canada: Canadian Journal of Earth Sciences, v. 15, p. 817-822
Plafker, George, and Hudson, T., 1980, Regional implications of Upper Triassic metavolcanic and metasedimentary rocks on the Chilkat Peninsula, southeastern Alaska: Canadian Journal of Earth Sciences, v. 17, p. 681-689.
Plafker, George, Hudson, T.L., and Silberling, N.J., 1979, Late Triassic fossils from a sequence of volcanic and sedimentary rocks on the Chilkat Peninsula, southeastern Alaska, in Johnson, K.M., and Williams, J.R., eds., The United States Geological Survey in Alaska--Accomplishments during 1978: U.S. Geological Survey Circular 804-B, p. B107-B110.
Still, J.C., 1988, Gold-copper Mineralization of the Chilkat Peninsula and Islands: U.S. Bureau of Mines Open-File Report 49-88, 39 p., 11 sheets.
Still, J.C., 1991, Section A: Haines - Klukwan - Porcupine subarea, in U.S. Bureau of Mines, Mineral investigations in the Juneau Mining District, Alaska, 1984-1988: Volume 2 - Detailed mine, prospect, and mineral occurrence descriptions: U.S. Bureau of Mines Special Publication VOL. 2A, 214 p., 9 sheets.
Still, J.C., Hoekzema, R.B., Bundtzen, T.K., Gilbert, W.G., Wier, K.R., Burns, L.E., and Fechner, S.A., 1991, Economic geology of Haines-Klukwan-Porcupine area, southeastern Alaska: Alaska Division of Geological and Geophysical Surveys Report of Investigations 91-4, 156 p., 5 sheets, scale 1:63,360.
|Reporters||T.C. Crafford (T. Crafford & Associates, Anchorage)|
|Last report date||2/4/2001|