Bulk Gold

Prospect, Active

Commodities and mineralogy

Main commodities Au; Sb
Other commodities As; Bi
Ore minerals arsenopyrite; gold; stibnite
Gangue minerals calcite; quartz

Geographic location

Quadrangle map, 1:250,000-scale NM
Quadrangle map, 1:63,360-scale D-1
Latitude 64.7912
Longitude -165.2874
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Bulk Gold prospect of Altar Resources consists of a large block of State claims in the upper valley of Dorothy Creek. The coordinates are near the center of the block of claims; the widespread mineralization include much of sections 13 and 14, parts of section 15, and much of sections 23 and 24, T. 8 S., R. 33 W., Kateel River Meridian. The claims include the old Hed and Strand mine (NM070). The location is accurate.

Geologic setting

Geologic description

The Bulk Gold prospect was first identified in 1992 by Altar Resources by following up stream sediment samples anomalous in gold, arsenic, and antimony (Andover Ventures, 2006, Nome Drill Program; 2007, Gold Results; 2008, Bulk Gold). Between 1993 and 2003, Altar, variously with Teck Exploration and Consolidated Aston collected over 400 soil samples over the deposit and about 50 rock-chip samples. They drilled 8 shallow holes in the deposit. The most encouraging intercepts were 0.78 gram of gold per ton over 45 feet and 25 feet that averaged 0.9 gram of gold per ton. A sample in the saddle at the head of Dahl Creek contained 1.65 grams of gold per tonne, and 9,510 parts per million (ppm) arsenic. 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 parts per billion (ppb) gold and 3,960 to 10,000 ppm arsenic. Andover Ventures is now (2008) the 100% owner.
In late 2006, Andover (2006, Nome Drill Program; 2007, Gold Results; 2008, Bulk Gold) drilled 8 shallow holes that totaled 285.7 meters. The most significant intercepts were 6.2 meters that that averaged 0.20 gram of gold per ton, 5.7 meters that averages 1.20 gram of gold per ton, and 6.7 meters that averaged 0.51 gram of gold per ton.
The property now being explored by Andover Resources (2008) has 4 types of mineralization on the property: 1) discordant, high-angle, high-grade stibnite-arsenopyrite-gold quartz veins (such as at the Hed and Strand mine (NM070)); 2) stratiform, possibly strata-bound disseminated gold mineralization at marble-schist contacts, 3) disseminated gold and arsenopyrite in metamorphosed felsic intrusive rocks, and 4) low-angle, high-grade gold-quartz veins. In 2001, Altar identified a 1400-foot-long geochemical anomaly, the 'Dripping Gold Zone', associated with marble and mineralized schist; soil samples contained as high as 5.1 grams of gold per ton and more than 10,000 ppm arsenic. One float sample of altered arsenopyrite-bearing intrusive rock contained 4.5 grams of gold per ton; another contained 1.5 gram of gold per ton, more than 200 ppm silver, and 338 ppm bismuth. There are also several other notable geochemical anomalies; the Dorothy Creek gold-arsenic anomaly which is about 3,000 feet long and the Discovery Hole gold-arsenic-antimony anomaly which is 1,600 feet long and 200 to 400 feet wide.
The Bulk Gold prospect is underlain mainly 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 metamorphic rocks in this area are part of the Nome Group derived from Proterozoic to early Paleozoic protoliths (Till and Dumoulin, 1994). The Nome Group rocks 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).
Geologic map unit (-165.290021701639, 64.7904411371278)
Mineral deposit model Disseminated gold and stratabound gold in metamorphic rocks, and in gold-arsenopyrite-stibnite quartz veins.
Age of mineralization Lode gold mineralization on Seward Peninsula is mostly related to higher temperature metamorphism in the mid-Cretaceous.
Alteration of deposit Quartz veining and apparently some disseminated pyrite and arsenopyrite in nearby schist.

Production and reserves

Workings or exploration The Bulk Gold prospect was first identified in 1992 by Altar Resources by following up stream-sediment anomalies in gold, arsenic, and antimony (Andover Ventures, 2006, Nome Drill Program; 2007, Gold Results; 2008, Bulk Gold) . Between 1993 and 2003, Altar variously with Teck Exploration and Consolidated Aston collected over 400 soil samples over the deposit and about 50 rock-chip samples. They drilled 8 shallow holes and dug 4 pits across a prominent area of mineralization. In late 2006, Andover Ventures (2006, Nome Drill Program; 2007, Gold Results) drilled 8 shallow holes that totaled 285.7 meters. In 2001, Altar identified a 1400-foot geochemical anomaly, the 'Dripping Gold Zone'. There are several other strong geochemically anomalous zones the Dorothy Creek gold-arsenic anomaly which is about 3,000 feet long, and the Discovery Hole gold-arsenic-antimony anomaly, which is 1,600 feet long and 200 to 400 feet wide.
Indication of production None
Reserve estimates None.

References

References

Andover Ventures, 2006, http://www.andoverventures.com/news/2006/index.php?&content_id=46 (News release, October 12, 2006).
Andover Ventures, 2007, http://www.andoverventures.com/news/2007/index.php?&content_id=59 (News release, February, 8, 2007).
Andover Ventures, 2008, Bulk Gold: http://www.andoverventures.com/projects/bulk_gold/ (as of March 4, 2008).
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.
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.
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.
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 (Hawley Resource Group); D.J. Grybeck (Port Ludlow, WA); D.J. Grybeck (Port Ludlow, WA)
Last report date 3/4/2008