| alteration: | Alteration at Cape Mountain is conspicuous by its absence. Clay development has been noted along fractures and bedding and minor tourmaline replacement of granite is present along some contacts. Tourmaline may also be disseminated in marble adjacent to granite. Minor skarn development includes pyroxene-fluorite +/- quartz, calcite, scheelite, scapolite, and pyrrohotite selvages in marble adjacent to small granite pegmatites. Calcite-muscovite-fluorite-tremolite rocks found on mine dumps may be a replacement selvage in marble but they are not abundant in the area. Discontinuous and small quartz veins also contain muscovite, some tourmaline, and locally abundant iron-oxide. However, many altered fractures or veins consisting of gossanous quartz+/-tourmaline contain only anomalous amounts of tin. The only sulfide mineral that is commonly present is arsenopyrite, both as disseminations in yellow-orange weathering seriate granite and in vein assemblages. |
| References: |
- Deposit:: Collier, A.J., 1904, Tin deposits of the York region, Alaska: U.S. Geological Survey Bulletin 229, 61 p.
- Deposit:: Knopf, Adolph, 1908, Geology of the Seward Peninsula tin deposits, Alaska: U.S. Geological Survey Bulletin 358, 71 p.
- Deposit:: Steidtmann, Edward, and Cathcart, S. H., 1922, Geology of the York tin deposits, Alaska: U.S. Geological Survey Bulletin 733, 130 p.
- Deposit:: Heide, H.E., Wright, W.S., and Sanford, R.S., 1946, Exploration of Cape Mountain lode-tin deposits, Seward Peninsula, Alaska: U.S. Bureau of Mines Report of Investigations 3978, 16 p.
- Deposit:: Mulligan, J.J., 1966, Tin-lode investigations, Cape Mountain area, Seward Peninsula, Alaska; with a section on petrography by W. L. Gnagy: U.S. Bureau of Mines Report of Investigations 6737, 43 p.
- Deposit:: Cobb, E.H., and Sainsbury, C.L., 1972, Metallic mineral resource map of the Teller quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-426, 1 sheet, scale 1:250,000.
- Deposit:: Sainsbury, C.L., 1972, Geologic map of the Teller quadrangle, Seward Peninsula, Alaska: U.S. Geological Survey Map I-685, 4 p., 1 sheet, scale 1:250,000.
- Deposit:: Hudson, T.L., and Arth, J. G., 1983, Tin-granites of Seward Peninsula, Alaska: Geological Society of America Bulletin, v. 94, p. 768-790.
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