|Quadrangle map, 1:250,000-scale||NM|
|Quadrangle map, 1:63,360-scale||D-1|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||The Hed & [and] Strand mine is in an east fork of upper Lost Creek, a south tributary to Stewart River; it is about 2.7 miles northeast of Mount Distin. The east fork tributary is known as Dahl Creek or Dahl Gulch (Cathcart, 1922, p. 224). The property is mainly in the SW1/4 section 14, T. 8 S., R. 33 W., Kateel River Meridian. The location given is in the approximate center of the easternmost of two patented claims and near the main workings of the mine. The Hed & [and] Strand mine is locality 8 of Hummel (1962 [MF 248]) and locality 30 of Cobb (1972 [MF 463], 1978 [OFR 78-93]); it is located within about 500 feet of the coordinates.|
The Hed & [and] Strand mine was developed by an adit and drifts on stibnite-bearing quartz veins in metamorphic rocks. The main vein was intersected 90 feet in from the portal of the adit; it strikes N45E and dips 48 N. At this point, the vein was followed by a 100-foot drift to the northeast and a 140-foot drift to the southwest (Mertie, 1918 [B 662-I, p. 425-449]). At the face of the 100-foot drift, the vein was about 2 feet wide and composed mostly of sheared schist with thin seams of stibnite on the hanging and foot walls. Where intersected in the adit, the vein was 4 feet wide; it consisted of white quartz and stibnite, with stibnite forming a footwall mass about 2 feet thick. A second subparallel vein was found 190 feet from the adit portal; it was drifted on for 170 feet. Lower grade material contains quartz and pyrite; Brooks (1916, p. 54-56) reported a mineralized mica schist with calcite, pyrite, and arsenopyrite. Mertie (1918, p. 438) reported that quartz with stibnite, exposed in the creek near the mine, assayed about 0.30 ounce of gold per ton; the associated stibnite contained about 0.1 ounce of gold per ton. The veins pinch and swell, and, as is typical of simple stibnite veins, the ore occurs in pods and kidneys (Bliss and Orris, 1986, p. 183-186).
About 106 tons of stibnite ore were mined and shipped in 1915 and 1916. This ore had a low gold content. Development continued at the mine in the late 1920s and early 1930s. When Anderson (1947) visited the mine in about 1943, about 10 tons of 30 percent antimony ore were on the dumps and about 30 to 40 tons were exposed in mine workings. At that time, there were about 1,000 feet of accessible mine workings.
The schist in the adit had a strike of about N15W and dipped at a low angle to the northeast. The main workings appear to lie within quartz-mica schist and a feldspar-rich epidote-bearing schist near a contact with massive marble (Bundtzen and others, 1994). The epidote-bearing schist may be part of a regional mafic metavolcanic assemblage that has an Ordovician protolith (Till and Dumoulin, 1994). Hummel (1962 [MF 248]) mapped an approximately east-west high-angle fault in Dahl Creek; the fault is upthrown on the south side. Earlier authors, including Mertie (1918 [B 662-I, p. 425-449]) and Cathcart (1922), noted a nearby metamorphosed granite body as possibly related to the mineralization, and Hummel (1962 [MF 248]) showed a small granite orthogneiss on the ridge east of the prospect. Granitic orthogneisses mapped by Bundtzen and others (1994) are about 1 mile north and 1 mile south of the prospect. The area is too complex to decipher with 1:63,360-scale mapping.The metamorphic rocks in this area are part of the Nome Group derived from Proterozoic or early Paleozoic protoliths (Till and Dumoulin, 1994). The Nome Group underwent regional blueschist facies metamorphism in the Late Jurassic or Early Cretaceous (Sainsbury, Coleman, and Kachadoorian, 1970; Forbes and others, 1984; Thurston, 1985; Armstrong and others, 1986; Hannula and McWilliams, 1995). The blueschist facies rocks were recrystallized to greenschist facies or higher metamorphic grades in conjunction with regional extension, crustal melting, and magmatism in the mid-Cretaceous (Hudson and Arth, 1983; Miller and Hudson, 1991; Miller and others, 1992; Dumitru and others, 1995; Hannula and others, 1995; Hudson, 1994; Amato and others, 1994; Amato and Wright, 1997, 1998). Lode gold mineralization on Seward Peninsula is mostly related to the higher temperature metamorphism in the mid-Cretaceous (Apodoca, 1994; Ford, 1993 [thesis]; Ford and Snee, 1996; Goldfarb and others, 1997). Lode antimony mineralization is inferred to be of the same approximate age.
|Geologic map unit||(-165.307222000234, 64.7909408448114)|
|Mineral deposit model||Simple Sb deposit (Cox and Singer, 1986; model 27d).|
|Mineral deposit model number||27d|
|Age of mineralization||Mid-Cretaceous?; structures controlling deposits postdate regional metamorphism; mineralization could be similar in age to lode gold deposits of Seward Peninsula.|
|Alteration of deposit||Quartz veining and apparently some disseminated pyrite and arsenopyrite in nearby schist.|
|Workings or exploration||Stibnite was discovered in Dahl Creek in about 1909, and development followed soon after. Workings consist of surface pits, an adit, and underground cross-cuts, drifts, and small stopes. Most of the workings were driven before 1918, and ore was produced and shipped in 1915 and 1916. Development continued at the mine in the late 1920s and early 1930s. When Anderson (1947) visited the mine in about 1943, about 10 tons of 30 percent antimony ore were on the dumps and about 30 to 40 tons were exposed in mine workings. At that time, there were about 1,000 feet of accessible mine workings. There was recent activity nearby in 1996-98 at the Bulk Gold prospect (NM071 and 072,) which includes the two patented Hed & [and] Strand claims.|
|Indication of production||Yes; small|
|Reserve estimates||Probably a few tens of tons of stibnite ore were left exposed in mine workings (Anderson, 1947).|
|Production notes||About 106 tons of stibnite ore were mined and shipped in 1915 and 1916. This ore had a low gold content. Development continued at the mine in the late 1920s and early 1930s. When Anderson (1947) visited the mine in about 1943, about 10 tons of 30 percent antimony ore were on the dumps and about 30 to 40 tons were exposed in mine workings. At that time, there were about 1,000 feet of open mine workings.|
Amato, J.M., and Wright, J.E., 1997, Potassic mafic magmatism in the Kigluaik gneiss dome, northern Alaska--A geochemical study of arc magmatism in an extensional tectonic setting: Journal of Geophysical Research, v. B102, no. 4, p. 8065-8084.
Amato, J.M., and Wright, J.E., 1998, Geochronologic investigations of magmatism and metamorphism within the Kigluaik Mountains gneiss dome, Seward Peninsula, Alaska, in Clough, J.G., and Larson, Frank, eds., Short Notes on Alaskan Geology 1997: Alaska Division of Geological and Geophysical Surveys Professional Report 118a, p. 1-21.
Anderson, Eskil, 1947, Mineral occurrences other than gold deposits in northwestern Alaska: Alaska Territorial Division of Mines Pamphlet 5-R, 48 p.
Apodoca, L.E., 1994, Genesis of lode gold deposits of the Rock Creek area, Nome mining district, Seward Peninsula, Alaska: Boulder, Colorado, University of Colorado, Ph.D. dissertation, 208 p.
Armstrong, R.L., Harakal, J.E., Forbes, R.B., Evans, B.W., and Thurston, S.P., 1986, Rb-Sr and K-Ar study of metamorphic rocks of the Seward Peninsula and southern Brooks Range, Alaska, in Evans, B.W., and Brown, E.H., eds., Blueschists and eclogites: Geological Society of America Memoir 164, p. 184-203.
Bliss, J.D., and Orris, G.J., 1986, Descriptive model of simple Sb deposits, in Cox, D.P., and Singer, D.A., eds., Mineral deposit models: U.S. Geological Survey Bulletin 1693, p. 183-186.
Bundtzen, T.K., Reger, R.D., Laird, G.M., Pinney, D.S., Clautice, K.H., Liss, S.A., and Cruse, G.R., 1994, Progress report on the geology and mineral resources of the Nome mining district: Alaska Division of Geological and Geophysical Surveys, Public Data-File 94-39, 21 p., 2 sheets, scale 1:63,360.
Cathcart, S.H., 1922, Metalliferous lodes in southern Seward Peninsula: U.S. Geological Survey Bulletin 722-F, p. 163-261.
Cobb, E.H., 1972, Metallic mineral resources map of the Nome quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-463, 2 sheets, scale 1:250,000.
Cobb, E.H., 1978, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Nome quadrangle, Alaska: U.S. Geological Survey Open-File report 78-93, 213 p.
Dumitru, T.A., Miller, E.L., O'Sullivan, P.B., Amato, J.M., Hannula, K.A., Calvert, A.T., and Gans, P.B., 1995, Cretaceous to Recent extension in the Bering Strait region, Alaska: Tectonics, v. 14, p. 549-563.
Forbes, R.B., Evans, B.W., and Thurston, S.P., 1984, Regional progressive high-pressure metamorphism, Seward Peninsula, Alaska: Journal of Metamorphic Geology, v. 2, p. 43-54.
Ford, R.C., 1993, Geology, geochemistry, and age of gold lodes at Bluff and Mt. Distin, Seward Peninsula, Alaska: Golden, Colorado School of Mines, Ph.D. dissertation, 302 p.
Ford, R.C., and Snee, L.W., 1996, 40Ar/39Ar thermochronology of white mica from the Nome district, Alaska--The first ages of lode sources to placer gold deposits in the Seward Peninsula: Economic Geology, v. 91, p. 213-220.
Goldfarb, R.J., Miller, L.D., Leach, D.L., and Snee, L.W, 1997, Gold deposits in metamorphic rocks in Alaska, in Goldfarb, R.J., and Miller, L.D., eds., Mineral Deposits of Alaska: Economic Geology Monograph 9, p. 151-190.
Hannula, K.A., and McWilliams, M.O., 1995, Reconsideration of the age of blueschist facies metamorphism on the Seward Peninusla, Alaska, based on phengite 40Ar/39Ar results: Journal of Metamorphic Geology, v. 13, p. 125-139.
Hannula, K.A., Miller, E.L., Dumitru, T.A., Lee, Jeffrey, and Rubin, C.M., 1995, Structural and metamorphic relations in the southwest Seward Peninsula, Alaska; Crustal extension and the unroofing of blueschists: Geological Society of America Bulletin, v. 107, p. 536-553.
Hudson, T.L., 1994, Crustal melting events in Alaska, in Plafker, G., and Berg, H. C., eds., The Geology of Alaska: Geological Society of America, DNAG, The Geology of North America, Vol. G-1, p. 657-670.
Hudson, T.L., and Arth, J. G., 1983, Tin granites of Seward Peninsula, Alaska: Geological Society of America Bulletin, v. 94, p. 768-790.
Hummel, C.L., 1962, Preliminary geologic map of the Nome D-1 quadrangle, Seward Peninsula, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-248, 1 sheet, scale 1:63,360.
Mertie, J.B., Jr., 1918, Lode mining and prospecting on Seward Peninsula, in Brooks, A.H., and others, Mineral resources of Alaska, report on progress of investigations in 1916: U.S. Geological Survey Bulletin 662, p. 425-449.
Miller, E.L., and Hudson, T.L., 1991, Mid-Cretaceous extensional fragmentation of a Jurassic-Early Cretaceous compressional orogen, Alaska: Tectonics, v. 10, p. 781-796.
Miller, E.L., Calvert, A.T., and Little, T.A., 1992, Strain-collapsed metamorphic isograds in a sillimanite gneiss dome, Seward Peninsula, Alaska: Geology, v. 20, p. 487-490.
Sainsbury, C.L., Coleman, R.G., and Kachadoorian, Reuben, 1970, Blueschist and related greenschist faces rocks of the Seward Peninsula, Alaska, in Geological Survey research 1970: U.S. Geological Survey Professional Paper 700-B, p. B33-B42.
Thurston, S.P., 1985, Structure, petrology, and metamorphic history of the Nome Group blueschist terrane, Salmon Lake area, Seward Peninsula, Alaska: Geological Society of America Bulletin, v. 96, p. 600-617.
Till, A.B., and Dumoulin, J.A, 1994, Geology of Seward Peninsula and St. Lawrence Island, in Plafker, G., and Berg, H.C., eds., The Geology of Alaska: Geological Society of America, DNAG, The Geology of North America, v. G-1, p. 141-152.
|Reporters||C.C. Hawley and Travis L. Hudson|
|Last report date||10/22/1999|