Lonesome; Gold Mint; Kelly Gold Mint; Hatcher Mine, Willow Creek District, Matanuska-Susitna Borough, Alaska, USA

Location: At the end of the uninproved road that runs parallel to the upper portion of the Little Susitna River. Marked with multiple adit symbols and labeled 'Lonesome Mine' on the Anchorage D-6 1:63,360-scale topographic map. The Gold Mint workings are about 2,000 ft east of road terminous. Accurate within 400 ft. Locality 35 from Cobb (1972) and locality 25 of MacKevett and Holloway (1977).
Geology: Quartz in narrow stringers and veins up to 18 inches wide cut fine-grained, fractured diorite or gabbro of early Paleocene to Late Cretaceous age. Stringers and veins contain free gold, pyrite, chalcopyrite, and the tellurides nagyagite and altaite. Veins strike N 35 to 50 W, and dips 40 to 62 SW. One vein is displaced several feet along a transverse fault (Ray, 1933; Ray, 1954). Wall-rock alteration within a few inches of the veins is intense, but seldom extends more than 10 to 12 inches beyond the quartz filling. Sericitization and carbonate alteration predominate, but there is some pyritization and in the outer parts of the alteration zone chloritization is present (Ray, 1954). A similar vein deposit is exposed to the southeast in an area of Eocene conglomerate of the Arkose Ridge Formation. This could indicate a post-Eocene age for mineralization of Lonesome mine gold deposits, because it may be younger than the Eocene continential rocks overlying the batholith of the Willow Creek district. A 2 to 3 inch vein of quartz assayed 19 oz/ton Au and 22 oz/ton Ag. The same vein is exposed and oxidized at surface and shows 400 oz/ton Ag (Ray, 1954).
Workings: Developed by surface trenching and several hundred feet of underground workings on 3 levels. By 1921 a tunnel was being driven on the upper vein and surface pits were being dug on the lower veins (Chapin, 1921). By 1922 the underground workings totalled 435 ft of adit, crosscut, shaft and raise. Mill was running in 1922 (Brooks and Capps, 1924). A five-stamp mill stood beside the Little Susutina River in the early 1930s. From 1946 to 1949 a new mill was installed and some underground development was done. The new mill and camp were built around 1946 although two five-stamp mills still stood in the old mill building (Stoll, 1997) The mine operated intermittently until 1949. A 2 to 3 inch vein of quartz assayed 19 oz/ton Au and 22 oz/ton Ag. The same vein is exposed and oxidized at surface and shows 400 oz/ton Ag (Ray, 1954). There is considerably more silver in these veins than in other veins of the district.
Age: Late Cretaceous or younger based on host rock age. A similar vein deposit is exposed to the southeast in an area of Eocene conglomerate of the Arkose Ridge Formation. This could indicate a post-Eocene age for mineralization of Lonesome mine gold deposits, because it may be younger than the Eocene continential rocks overlying the batholith of the Willow Creek district (Ray, 1954).
Alteration: Wall-rock alteration within a few inches of the veins is intense, but seldom extends more than 10 to 12 inches beyond the quartz filling. Sericitization and carbonate alteration predominate, but there is some pyritization and in the outer parts of the alteration zone chloritization is present (Ray, 1954). Surface oxidation.
Production: Smith (1930) listed the Marion-Twin Gold Mining Company, the owner of the Lonesome Mine, as one of the largest producers in the district in 1928. Production reported intermittently between 1931 and 1949. Amount of total production is unknown.

Commodities (Major) - Ag, Au; (Minor) - Cu
Development Status: Yes; small
Deposit Model: Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a)

References:
Berg, H.C., and Cobb, E.H., 1967, Metalliferous lode deposits of Alaska: U.S. Geological Survey Bulletin 1246, 254 p. Brooks, A.H., 1925, Alaska's mineral resources and production, 1923: U.S. Geological Survey Bulletin 773-A, p. 3-52. Brooks, A.H., and Capps, S.R., 1924, The Alaska mining industry in 1922: U.S. Geological Survey Bulletin 755-A, p. 1-56. Chapin, Theodore, 1921, Lode developments in the Willow Creek district: U.S. Geological Survey Bulletin 714-D, p. 201-206. Cobb, E.H., 1972, Metallic mineral resources map of the Anchorage quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-409, 1 sheet, scale 1:250,000. Cobb, E.H., 1979, Summary of references to mineral occurrences (other than mineral fuels and construction materials in the Anchorage quadrangle, Alaska: U.S. Geological Survey Open-File Report 79-1095, 184 p. MacKevett, E.M., Jr., and Holloway, C.D., 1977, Map showing metalliferous and selected non-metalliferous mineral deposits in the eastern part of southern Alaska: U.S. Geological Survey Open-File Report 77-169-A, 99 p., 1 sheet, scale 1:1,000,000. Ray, J.C., 1933, The Willow Creek gold-lode district, Alaska: U.S. Geological Survey Bulletin 849-C, p. 165-229. Ray, R.G., 1954, Geology and ore deposits of the Willow Creek Mining district, Alaska: U.S. Geological Survey Bulletin 1004, 86 p. Smith, P.S., 1929, Mineral industry of Alaska in 1926: U.S. Geological Survey Bulletin 797, p. 1-50. Smith, P.S., 1930, Mineral industry of Alaska in 1927: U.S. Geological Survey Bulletin 810-A, p. 1-64. Smith, P.S., 1930, Mineral industry of Alaska in 1928: U.S. Geological Survey Bulletin 813-A, p. 1-72. Smith, P.S., 1932, Mineral industry of Alaska in 1929, in Smith, P.S., and others Mineral resources of Alaska, report on progress of investigations in 1929: U.S. Geological Survey Bulletin 824-A, p. 1-81. Smith, P.S., 1933, Mineral industry of Alaska in 1930: U.S. Geological Survey Bulletin 836-A, p. 1-83. Smith, P.S., 1933, Mineral industry of Alaska in 1931: U.S. Geological Survey Bulletin 844-A, p. 1-81. Smith, P.S., 1934, Mineral industry of Alaska in 1932: U.S. Geological Survey Bulletin 857-A, p. 1-91. Smith, P.S., 1934, Mineral industry of Alaska in 1933: U.S. Geological Survey Bulletin 864-A, p. 1-94. Stoll, W.M., 1997, Hunting for gold in Alaska's Talkeetna Mountains 1897-1951--with a background sketch of Alaska's great gold-lode camps: Greensburg, Pennsylvania, Henry Printing, 301 p.