|Quadrangle map, 1:250,000-scale||KC|
|Quadrangle map, 1:63,360-scale||A-6|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||
The location of the War Eagle mine is either (1) at an elevation of about 1450 feet on the northeast ridgeline of Punch Hill; or (2) between 450 and 700 feet elevation on the northeast flank of Punch Hill . The first location is approximated from fig. 10 in Wright and Wright (1908); the second assumes that the War Eagle corresponds to the mine and adit symbols at loc. 311 (10, 11) in Maas and others (1995, fig. 58). For this record, the map site is at the mine symbol (311-10), in section 17, T. 77 S., R. 91 E., of the Copper River Meridian. The location is accurate within a few hundred feet.Also see Additional comments.
Southern Gravina Island is underlain by an assemblage of undivided Silurian or Ordovician metamorphosed bedded and intrusive rocks; a stock and associated dikes of Silurian trondhjemite that cuts the metamorphic assemblage; and a sequence of Upper Triassic carbonate, clastic, rhyolitic, and basaltic strata that unconformably overlies the older rocks (Berg, 1973, 1982; Berg and others, 1988). The rocks are complexly folded and are cut by high-angle faults and by low-angle thrust faults. In many places, the Triassic rhyolite and the rocks beneath it are permeated by microscopic particles of hydrothermal hematite, giving them a pink, purple, or red hue (Berg, 1973, p. 14).
According to Brooks (1902, p. 70), the War Eagle deposit consists of quartz veins in shear or breccia zones in greenschist. One such mineralized fault zone, exposed in a tunnel, is about 3 feet thick, strikes N30E, and dips 30S. The veins contain pyrite, chalcopyrite, and minor free gold. Wright and Wright (1908, p. 140) describe the deposit only as a 10-foot vein that contains pyrite and chalcopyrite, has well-defined walls, and evidently is a southeast continuation of the Hobo deposit (KC115). An 1800-foot-long crosscut tunnel driven in the early 1900s intersected 6 or more veins (Brooks, 1902). Other workings at that time included a 40-foot shaft, 2 adits 100 vertical feet apart, and 700 feet of additional tunnel.
Maas and others' (1995, p. 227) description of the mineral deposits in the Seal Cove area probably applies in general to the War Eagle deposit. They report that chalcopyrite occurs as vein fillings, disseminations, and in fault breccias west and northwest of Seal Cove. The mineralized breccias have a siliceous matrix. Small quartz-barite veins with galena and sphalerite have been found west of Seal Cove, and on the northeast slopes of Punch Hill. The rocks at the War Eagle mine are cut by a high-angle fault that strikes west and northwest (Maas and others, (1995, fig 58).Maas and others (1995, p. 227) report that copper mineralization on southern Gravina Island generally is associated with faulting. The deposits are mainly in meta-andesite (greenschist) and trondhjemite, but also in the overlying Triassic strata. The deposits are chiefly chalcopyrite- and pyrite-bearing quartz fissure veins, but the sulfide minerals also occur as disseminations in the metavolcanic rocks, in silicified zones in the trondhjemite, and as clasts or pods in silicified or carbonatized breccia. The character and setting of the deposits suggest that they mainly are polymetallic veins of Late Triassic or younger age.
|Geologic map unit||(-131.739678419457, 55.1866530305375)|
|Mineral deposit model||Polymetallic veins (Cox and Singer, 1986; model 22c)|
|Mineral deposit model number||22c|
|Age of mineralization||Late Triassic or younger.|
|Alteration of deposit||Probably local silicification, carbonatization, pyritization, and introduction of hydrothermal hematite.|
|Workings or exploration||An 1800-foot-long crosscut tunnel driven in the early 1900s intersected 6 or more veins (Brooks, 1902). Other workings at that time included a 40-foot shaft, 2 adits 100 vertical feet apart, and 700 feet of additional tunnel.|
|Indication of production||Yes; small|
|Production notes||An unknown, but probably small, amount of gold probably was recovered from the War Eagle mine in the early 1900s (Cobb and Elliott, 1980, p. 109).|
Additional commentsIn the early 1900s, the War Eagle mine was on the property of Patterson and Co. (Cobb and Elliott, 1980, p. 146).
Berg, H.C., 1982, The Alaska Mineral Resource Assessment Program; guide to information about the geology and mineral resources of the Ketchikan and Prince Rupert quadrangles, southeastern Alaska: U.S. Geological Survey Circular 855, 24 p.
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.
Brooks, A.H., 1902, Preliminary report on the Ketchikan mining district, Alaska, with an introductory sketch of the geology of southeastern Alaska: U.S. Geological Survey Professional Paper 1, 120 p.
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 in the Ketchikan and Prince Rupert quadrangles, Alaska: U.S. Geological Survey Open-File Report 78-73B, 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.
|Reporters||H.C. Berg, USGS|
|Last report date||7/5/1999|