Bulk Gold (West)

Site Name

Primary: Bulk Gold (West)

---

Commodity

Primary: Antimony
Primary: Gold
Secondary: Arsenic

---

Location

State: Alaska
District: Nome

---

Land Status

Not available

---

Holdings

Not available

---

Workings

Not available

---

Ownership

Not available

---

Production

Not available

---

Deposit

Record Type: Site
Operation Category: Prospect
Operation Type: Unknown
Years of Production:
Organization:
Significant:

---

Physiography

Not available

---

Mineral Deposit Model

Model Name: Low-sulfide Au-quartz vein

---

Orebody

Not available

---

Structure

Not available

---

Alterations

Alteration Type: L
Alteration Text: Quartz veining and apparently some disseminated pyrite and arsenopyrite in nearby schist.

---

Rocks

Not available

---

Analytical Data

Not available

---

Materials

Ore: Stibnite
Ore: Gold
Ore: Arsenopyrite
Gangue: Quartz
Gangue: Calcite

---

Comments

Comment (Reference): Primary Reference = This report

Comment (Geology): Geologic Description = The Bulk Gold prospect was identified from stream sediment sampling and soil samples collected between 1994 and 1998 (Daniel Lajack, written communication,1999). The geochemical work was followed by trenching and two short diamond drill holes in 1998. Work on the prospect has been done by Altar Resources and Teck Exploration Company. Teck Exploration Company ran a soil survey that extended from west of the Hed & [and] Strand mine (NM070) to past the head of Dorothy Creek in the east Bulk Gold prospect). Soils collected above the Hed & [and] Strand mine contained as much as 550 ppb gold, 884 ppm arsenic and 66 ppm antimony. Upper Dahl Creek, above the Hed & [and] Strand claims, was highly anomalous in gold, arsenic, and antimony. A sample in the saddle at the head of Dahl Creek contained 1.65 grams of gold per tonne, 9,510 ppm arsenic and 48 ppm. This saddle area was trenched and drilled in 1998. Four pits were dug at 300-foot intervals across the saddle. Bedrock samples from these pits contained 575 to 1,210 ppb gold and from 3,960 to 10,000 ppm arsenic. Anomalous results were also found in 30-foot and 50-foot diamond drill holes. Although antimony is somewhat anomalous in the samples and antimony occurrences have been identified in the area (NM066 to NM070), the prospect is mainly characterized by elevated gold and arsenic values. The west part of the Bulk Gold prospect is mainly underlain by massive marble and feldspathic epidote-bearing schist. 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 at the Hed & [and] Strand mine, and Hummel (1962 [MF 248]) and Bundtzen and others (1994) mapped granitic orthogneisses in the area. 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 Proterzoic to 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).

Comment (Deposit): Model Name = Possibly disseminated and stratabound in metamorphic rocks, or in low sulfide Au-quartz veins (Cox and Singer, 1986; model 36a).

Comment (Deposit): Other Comments = the project found widespread anomalies including a strong gold-arsenic system in upper Dahl Creek. Controls on mineralization are not defined.

Comment (Geology): Age = Mid-Cretaceous; structures controlling deposits post-date regional metamorphism; mineralization could be similar in age to many lode gold deposits of Seward Peninsula.

Comment (Exploration): Status = Active

Comment (Workings): Workings / Exploration = Work has consisted of stream sediment sampling, followed by soil geochemistry and some trenching and drilling in 1998.

---

References

Reference (Deposit): 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.

Reference (Deposit): 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.

Reference (Deposit): Amato, J.M., Wright, J.E., Gans, P.B., and Miller, E.L., 1994, Magmatically induced metamorphism and deformation in the Kigluaik gneiss dome, Seward Peninsula, Alaska: Tectonics, v. 13, p. 515-527.

Reference (Deposit): 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, The Geology of North America, DNAG, v. G-1, p. 141-152.

Reference (Deposit): 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.

Reference (Deposit): Hudson, T.L. 1994, Crustal melting events in Alaska, in Plafker, G., and Berg, H. C., eds., The Geology of Alaska: Boulder, Colorado, Geological Society of America, The Geology of North America, v. G-1, p. 657-670.

Reference (Deposit): 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.

Reference (Deposit): 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.

Reference (Deposit): 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.

Reference (Deposit): 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.

Reference (Deposit): 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, 482 p.

Reference (Deposit): 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.

Reference (Deposit): 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.

Reference (Deposit): 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.

Reference (Deposit): 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.

Reference (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.

Reference (Deposit): 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.

Reference (Deposit): Cathcart, S.H., 1922, Metalliferous lodes in southern Seward Peninsula: U.S. Geological Survey Bulletin 722, p. 163-261.

Reference (Deposit): 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.

Reference (Deposit): 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.

Reference (Deposit): 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.

Reference (Deposit): 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.

---

The Top Ten Gold Producing States

These ten states contributed the most to the gold production that built the West from 1848 through the 1930s. The Top Ten Gold Producing States.