Main commodities | Pb |
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Other commodities | Ag; Au; Ba; Cu; Zn |
Ore minerals | chalcopyrite; barite; galena; gold; sphalerite; tetrahedrite |
Gangue minerals | quartz |
Quadrangle map, 1:250,000-scale | GU |
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Quadrangle map, 1:63,360-scale | D-1 |
Latitude | 62.857 |
Longitude | -144.3 |
Nearby scientific data | Find additional scientific data near this location |
Location and accuracy | The Tom Burns prospect is on the ridge between the upper East Fork of Indian Creek and Indian Creek (sometimes called the West Fork) at an elevation of about 4,800 feet. The prospect is approximately on the section line less than 0.1 mile north of the southeast corner of section 32, T. 13 N., R. 6 E., Copper River Meridian. The prospect is locality 4 of both Richter and Matson (1972) and MacKevett and Holloway (1977). The location is in the approximate center of the Tom Burns 1 and 2 claims and is accurate within 1000 feet. |
Geologic descriptionThe Tom Burns prospect is near the west contact of the Pennsylvanian to Permian, Ahtell Creek intrusive which here is quartz monzonite. Based on float and prospect pits, the Tom Burns vein strikes northwest and dips northeasterly. The vein varies from about 2 to 8 feet wide and consists mostly of quartz. Sulfides, predominantly galena with minor chalcopyrite and tetrahedrite, form bands on the walls of vein as much as one foot wide. A sample cut from the westernmost outcrop of the Tom Burns No. 1 claim contains trace amounts of gold and silver, 12.37 percent lead, and 0.22 percent copper. A representative sample of float collected from the Tom Burns No. 2 claim contained 0.01 ounce of gold per ton, a trace of silver and copper. and 7.82 percent lead (Thorne, 1946, fig. 3 and p. 5-6). The vein was examined in 1936 by Moffit (1938, p. 46) who reported galena and quartz but exposures were too badly sloughed to determine anything about the vein. Samples of float and of vein material in place contained as much as 0.01 ounce of gold per ton, trace Ag, 12.37% Pb, and 0.22% Cu (Moffit, 1932, 1938). The prospect was reexamined by WGM Inc. in their study of Ahtna Native Corporation lands (WGM, 1978). The WGM geologists reported barite and zinc (sphalerite?) in addition to the minerals previously reported ; the WGM Inc. mapping indicates the strike of the vein is subparallel to the contact of the Ahtell intrusive. | |
Geologic map unit | (-144.302205841731, 62.8566039000421) |
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Mineral deposit model | Polymetallic vein (Cox and Singer, 1986; model 22c) |
Mineral deposit model number | 22c |
Age of mineralization | Emplaced subseqent to or is related to the border phase of the Pennsylvanian to Permian, Ahtell pluton. |
Workings or exploration | Caved open cuts. |
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Indication of production | None |
Additional commentsAdditional information can be obtained from Ahtna Minerals in Anchorage, Alaska. |
MRDS Number | A011837 |
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References | |
Reporters | W.T. Ellis (Alaska Earth Sciences), C.C. Hawley (Hawley Resource Group), and W.J. Nokleberg (U.S. Geological Survey) |
Last report date | 11/27/2000 |