|Quadrangle map, 1:250,000-scale||NB|
|Quadrangle map, 1:63,360-scale||A-2|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This prospect is on the north bank of Chathenda Creek about 0.9 mile upstream from the mouth of Salt Creek and 1.2 miles downstream from Bonanza. The site is in the SW1/4 of section 34, T. 4 N., R. 19 E. of the Copper River Meridian. This is locality 39 of Richter and others (1975). Cobb and Richter (1980) included this prospect under the name 'Chathenda Cr.'. It is located to within a few hundred feet.|
Geologic descriptionThis prospect consists of gold-bearing quartz-pyrite veins, some of which contain marcasite. The veins are in a zone up to 10 feet wide of mineralized, volcanic and diorite country rocks (Capps, 1916; Pilgrim, 1931, p. 66-68). The mineralized zone strikes N 65 W and dips 78 S. Gold values of 0.01 and 0.10 ounce of gold per ton were reported by Pilgrim (1931). A chip sample across 5 feet of limonite-stained, fine-grained, volcanic rock contained 1.5 parts per million (ppm) silver, 1,500 ppm chromium, 500 ppm copper, and 300 ppm lead (Richter and Matson, 1970 [OFR 70-275]). The host rocks are volcanic and volcaniclastic rocks of the Cretaceous, Chisana Formation (Richter and Jones, 1973). These volcanic rocks are intruded by the mid-Cretaceous, Chisana pluton about 1,000 feet north of the prospect. The Chisana pluton varies from clinopyroxene diorite to monzonite and has been dated by K/Ar methods as 110 +/- 3.0 Ma (Richter, Lanphere, and Matson, 1975).
|Geologic map unit||(-141.927827781065, 62.0784337281245)|
|Mineral deposit model||Polymetallic veins (Cox and Singer, 1986; model 22c)|
|Mineral deposit model number||22c|
|Age of mineralization||Mid-Cretaceous? The deposit may be related to emplacement of the Chisana pluton which has a K/Ar date of 110 +/- 3.0 Ma (Richter, Lanphere, and Matson, 1975).|
|Alteration of deposit||Pyrite and quartz veining and replacement(?); oxidation has produced abundant iron-staining.|
|Workings or exploration||There are open cuts and two short adits in this area (Capps, 1916). A number of small gold-bearing quartz-pyrite lodes occur in mineralized volcanic country rock of the Cretaceous, Chisana Formation on the north side of Chathenda Creek (also see NB092 and NB093). By 1940 a large group of claims had been staked in this area but exploration, including trenches and some short adits, was unsuccessful.|
|Indication of production||None|
Additional commentsThe prospect is in the Wrangell-St. Elias National Preserve.
Capps, S.R., 1916, The Chisana-White River district, Alaska: U.S. Geological Survey Bulletin 630, 130 p.
Cobb, E.H., and Richter, D.H., 1980, Summaries of data on and list of references to metallic and selected nonmetallic mineral deposits in the Nabesna quadrangle, Alaska: U.S. Geological Survey Open-File Report 80-927, 117 p.
Pilgrim, E.R., 1931, in Stewart, B.D., Report on cooperation between the Territory of Alaska and the United States in making mining investigations and in inspection of mines for the biennium ending March 31, 1931: Alaska Terrirorial Department of Mines, p. 66-68.
Richter, D.H., and Jones, D.L., 1973, Reconnaissance geologic map of the Nabesna A-2 quadrangle, Alaska: U.S. Geological Survey Miscellaneous Investigations Series Map I-749, 1 sheet, scale 1:63,360.
Richter, D.H., and Matson, N.A., Jr., 1970, Geochemical data from the Nabesna A-2 quadrangle, Alaska: U.S. Geological Survey Open-File Report 70-275, 12 p., 1 sheet, scale 1:63,360.
Richter, D.H., Lanphere, M.A., and Matson, N.A., Jr., 1975, Granite plutonism and metamorphism, eeastern Alaska Range, Alaska: Geological Society of American Bulletin, v. 86, p. 819-820.
|Reporters||Travis L. Hudson (Applied Geology)|
|Last report date||11/24/2002|