|Quadrangle map, 1:250,000-scale||KC|
|Quadrangle map, 1:63,360-scale||B-5|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This site includes several prospects or occurrences in about a square-mile area in and near the city of Ketchikan. They are at elevations ranging from near sea level to about 300 feet, and are from 0.1 to 0.7 mile northwest of the mouth of Ketchikan Creek in sections 19, 24, and 30, T. 75 S., R. 91 E., of the Copper River Meridian. The location is accurate. The site is locality 65 in Elliott and others (1978), and localities 276-280 in Maas and others (1995). The old workings on several of the prospects are concealed by housing and other city development, or are on private lots and have been filled in or covered by the owners (Maas and others, 1995, p. 194).|
This part of Revillagigedo Island is underlain mainly by marine, andesitic or basaltic volcanic rocks and pelitic sedimentary rocks that are intruded by Cretaceous stocks, sills, and dikes of feldspar-porphyritic granodiorite, and by a stock and probably related plugs of Tertiary gabbro (Berg and others, 1988). The strata were regionally metamorphosed to greenschist-grade phyllite and semischist in Late Cretaceous time. They subsequently were contact metamorphosed to hornblende hornfels near some of the Cretaceous granodiorite contacts, and, more widely, peripheral to the Tertiary gabbro. The pre-metamorphic age range of the strata is uncertain. Berg and others (1988) note that they closely resemble Upper Jurassic to mid-Cretaceous flysch and volcanic rocks nearby on Gravina Island. The country rocks are cut by a high-angle fault along Tongass Narrows that displays about 4 miles of right-lateral offset.
The Laskawa or Shoenbar 'Mine' consists of a N 50 W, 50 NE sulfide-bearing band of phyllite and greenschist, cut by sulfide-bearing quartz fissure veinlets. The sulfide minerals are pyrite and chalcopyrite, and there were early reports of gold and silver (Wright and Wright, 1908, p. 152; Cobb and Elliott, 1980, p. 69). Roppel (2005) did considerable historic research on the 'Mine' and concluded that it was 'more business on paper than on what proved to be worthless ground'. The deposit was discovered in 1899 when John Shoenbar arrived in Ketchikan and purchased several claims along Ketchikan Creek. By 1904, the deposit was explored by two shafts, 125 and 85 feet deep, a short tunnel, and surface stripping. Shoenbar spend much time in the East trying to attract capital to develop the property but most of the work on the consisted of acquiring additional claims, constructing buildings and tramways, developing water rights, trying to develop power, and filing papers for patent to the claims. Little was done on the property by Shoenbar after 1904 although his claims were patented by 1920. In the 1930s, there was a brief attempt to cyanide the dump of the shafts; the results were disappointing although what little gold that may have been produced would have been the only gold produced from the property. In later years, the claims were developed and became part of the city of Ketchikan. A middle school, street, and bypass are named for Shoenbar, but all are misspelled 'Schoenbar' (Allen, 2002).
The following five occurrences were examined in the early 1990s by Maas and others (1995, locs. 276-280), who named them either from U.S. Bureau of Mines claim records, or, informally, for local landmarks.
Loc. 276: Forest Avenue quarry. Samples of silicified(?) volcanic rocks contained up to 222 parts per billion (ppb) gold, 2970 parts per million (ppm) copper, and 111 ppm molybdenum.
Loc. 277: Prison parking lot. A 2-foot sample of silicified(?) volcanic rock contained 2.1 ppm gold.
Loc. 278: Nevada lode. A 7-foot sample of silicified(?) greenstone contained 1282 ppb gold and 5,705 ppm copper. A shaft on this property was plugged.
Loc. 279: American Legion quarry. Samples of unidentified material contained up to 2,235 ppm zinc.Loc. 280: Cape Fox. Samples of unidentified material contained up to 20 ppb gold. This property was explored in the early 1900s by a 24-foot adit and a shaft, which have been plugged.
|Geologic map unit||(-131.643585924117, 55.3489536845894)|
|Mineral deposit model||Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a).|
|Mineral deposit model number||36a|
|Age of mineralization||The quartz fissure veins that crosscut the metamorphic foliation probably are Late Cretaceous or younger.|
|Workings or exploration||Workings in the early 1900s included surface cuts and several short adits, shafts, and tunnels most of which have been covered by housing or commercial development, or filled in.|
|Indication of production||None|
|Production notes||Probably none or very small.|
Allen, June, 2002, Name it Schoenbar: What's in a name?: http://www.sitnews.org/JuneAllen/060902_schoenbar.html (as of March 4, 2008).
Berg, H.C., Elliott, R.L., and Koch, R.D., 1988, Geologic map of the Ketchikan and Prince Rupert quadrangles, southeastern Alaska: U.S. Geological Survey Mineral Investigations Series Map I-1807, 27 p., scale 1:250,000.
Cobb, E.H., and Elliott, R.L., 1980, Summaries of data on and lists of references to metallic and selected nonmetallic mineral deposits in the Ketchikan and Prince Rupert quadrangles, Alaska: U.S. Geological Survey Open-File Report 80-1053, 157 p.
Elliott, R.L., Berg, H.C., and Karl, S.M., 1978, map and table describing metalliferous and selected non-metalliferous mineral deposits, Ketchikan and Prince Rupert quadrangles, Alaska: U.S. Geological Survey Open-File Report 78-73-B, 17 p., 1 sheet, scale 1:250,000.
Maas, K.M., Bittenbender, P E., and Still, J.C., 1995, Mineral investigations in the Ketchikan mining district, southeastern Alaska: U.S. Bureau of Mines Open-File Report 11-95, 606 p.
Roppel, Patricia, 2005, Striking it rich! Gold mining in southern Southeastern Alaska: Greenwich, Connecticut, Coachlamp Productions, 286 p.
|Reporters||H.C. Berg (USGS); D.J. Grybeck (Port Ludlow, WA)|
|Last report date||3/4/2008|