|Quadrangle map, 1:250,000-scale||ID|
|Quadrangle map, 1:63,360-scale||D-1|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This prospect is an area about 0.6 by 1.2 mile in size centered on VABM Tatalina. It is at an elevation of about 2,400 feet, just south of the middle of the northern boundary of section 29, T. 31 N., R. 36 W., of the Seward Meridian. The location is accurate.|
Geologic descriptionThis prospect near VABM Tatalina consists of several tourmaline-bearing breccia bodies in an irregularly shaped body of quartz porphyry near the Tatalina Mountain syenite intrusion. The Tatalina Mountain syenite body just east of the prospect area has a 40K/40Ar biotite age of 61.3 Ma (Bundtzen and Laird, 1983). The tourmaline breccias crop out discontinuously over an area about 0.6 mile by 1.2 mile in size south of VABM Tatalina. Near the breccia, tourmaline has replaced some of the hornfels and the quartz syenite pluton as well as the quartz porphyry intrusion (D.B. Obolewicz, written communication, 1981; Bundtzen and Laird, 1983). Grab samples of stained tourmaline breccia have ocherous coatings without sulfides and contained up to 0.96 percent lead, 90.0 parts per million (ppm) silver, 240 ppm copper, 900 ppm zinc, 45 parts per billion (ppb) gold, more than 1,000 ppm arsenic, 200 ppm antimony, 760 ppb mercury, and 28 ppm tin (D.B. Obolewicz, written communication, 1981). Samples collected by McGimsey and others (1988) contained up to 10.0 ppm silver, 500 ppm lead, and 20 ppm tin. Two samples collected by Bundtzen and Laird (1983) contained 5.0 ppm silver and 1,000 ppm vanadium. In 2001, North Star Exploration, Inc., conducted a soil survey over the prospect and detected several elliptical-shaped anomalous areas. The soils contained up to 125 parts per billion (ppb) gold, 16.8 parts per million (ppm) silver, 1,039 ppm lead, 1,096 ppm zinc, 4.4 ppm cadmium, 1,308 ppm boron, 438 ppm arsenic, 54 ppm antimony, and 104 ppm bismuth (North Star Exploration, Inc., unpublished data, 2001). The elevated gold values in the soil were more sparsely distributed than the anomalous base metal and silver values. Bundtzen and Miller (1997) correlate this prospect with other silver-tin-polymetallic prospects in the Kuskokwim mineral belt.
|Geologic map unit||(-156.071262168547, 62.7525232092792)|
|Mineral deposit model||Sn-polymetallic veins (Cox and Singer, 1986; model 20b).|
|Mineral deposit model number||20b|
|Age of mineralization||Undated; probably genetically related to emplacement of Tatalina Mountain pluton which has been dated at 61.3 Ma (Bundtzen and Laird, 1983; Bundtzen and Miller, 1997).|
|Alteration of deposit||Greisen developed in tourmaline breccia pipes.|
|Workings or exploration||There are at least six old prospects near VABM Tatalina. Surface samples were collected by the Alaska Division of Geological and Geophysical Surveys in 1978, by Anaconda Minerals in 1981, by the U.S. Geological Survey in the 1985, and by North Star Exploration, Inc. in 2001.|
|Indication of production||None|
Bundtzen, T.K., and Laird, G.M., 1983, Geologic map of the Iditarod D-1 quadrangle, Alaska: Alaska Division of Geological and Geophysical Surveys Professional Report 78, scale 1:63,360.
Bundtzen, T.K., and Miller, M.L., 1997, Precious metals associated with Late Cretaceous-early Tertiary igneous rocks of southwestern Alaska, in Goldfarb, R.J., and Miller, L.D., eds., Mineral Deposits of Alaska: Economic Geology Monograph 9, p. 242-286.
McGimsey, R.G., Miller, M.L., and Arbogast, B.F., 1988, Paper version of analytical results, and sample locality map for rock samples from the Iditarod quadrangle, Alaska: U.S. Geological Survey Open-File Report 88-421-A, 110 p., 1 sheet, scale 1:250,000.
Miller, M.L., and Bundtzen, T.K., 1994, Generalized geologic map of the Iditarod quadrangle, Alaska showing potassium-argon, major oxide, trace element, fossil, paleocurrent, and archeological sample localities: U.S. Geological Survey Miscellaneous Field Studies Map MF-2219-A, 48 pages; 1 sheet, scale 1:250,000.
|Reporters||T.K. Bundtzen (Pacific Rim Geological Consulting, Inc.), M.L. Miller (U.S. Geological Survey); and C.C. Hawley (Hawley Resource Group)|
|Last report date||5/17/2003|