Red Dog

Mine, Active

Alternative names

Qanaiyaq
Hilltop
Aqqaluk
Paalaaq

Commodities and mineralogy

Main commodities Ag; Pb; Zn
Other commodities As; Ba; Cu; Sb
Ore minerals barite; bornite; boulangerite; chalcopyrite; covellite; galena; marcasite; polybasite; pyrite; pyrrhotite; sphalerite; tetrahedrite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale DL
Quadrangle map, 1:63,360-scale A-2
Latitude 68.0704
Longitude -162.8379
Nearby scientific data Find additional scientific data near this location
Location and accuracy This record describes the main Red Dog deposit mined since 1989, and the nearby Qanaiyak (Hilltop), Aqqaluk, and Paalaaq deposits that are part of the Red Dog mine. The map site is at the open pit of the main deposit, 2 miles northwest of Deadlock Mountain in section 20, T. 31 N., R. 18 W., of the Kateel Meridian. The Qanaiyak (Hilltop) deposit is one mile south of the main deposit; Aqqaluk is 1,500 feet north of the Main deposit, across Red Dog Creek, and Paalaaq is just east-northeast of Aqqaluk. The location is accurate to within 500 feet.

Geologic setting

Geologic description

The DeLong Mountains are characterized by stacked and folded, thrust allochthons (Ellersieck and others, 1990; Kelley and Jennings, 2004; [Supplemental map]). The structurally lower allochthons are composed of Devonian through Cretaceous clastic and chemical sedimentary rocks. The two uppermost allochthons contain Jurassic or older mafic and ultramafic igneous sequences. Minor igneous rocks of basic composition are exposed 0.6 mile northeast of Red Dog (Kulas, 1992).
The Red Dog deposit is a shale-hosted, sedimentary exhalite deposit (SEDEX) deposit (Kelley and Jennings, 2004). The deposit is in multiple, superimposed thrust fault slices of stratabound, massive sulfides and barren mudstones. The host rock is black, siliceous shale and chert of the Ikalukrok unit of the Mississippian to Pennsylvanian Kuna Formation (Dumoulin and others, 2004). The Kivalina unit, an interbedded calcarenite and calcareous shale, is the footwall of the deposit. Mineralization is syngenetic with respect to sediment deposition. Silicification occurs within and peripheral to the main mass of sulfides. A barite facies is concentrated toward the top and periphery of the deposit. Major sulfides in decreasing order of abundance are sphalerite, pyrite, marcasite, and galena. Rare disseminated chalcopyrite and pyrrhotite occur in the sphalerite. The ore textures are massive, fragmental, chaotic, and veined; they rarely show typical sedimentary layering (Kelley, Leach, and others, 2004). The upper portion of the ore body is oxidized. The deposit is weakly enriched upward in lead relative to zinc.
The Main deposit consists of two major mineralized thrust fault slices and one lesser mineralized fault slice. It extends 1,600 meters in a northwest direction and varies in width from 150 to 975 meters. High-grade portions of the deposit are up to 135 meters thick. The base of the Main deposit is a tectonic melange zone which separates it from the Cretaceous Okpikruak Formation.
The Qanaiyaq (the old Hilltop) ore body is a horizontal klippe of the same ore body as the Main deposit (Moore and others, 1986). The mineralized zone is 490 meters long by 245 meters wide and the exhalite package is less than 100 meters thick. The mineral assemblage is similar to that at the Main deposit except that it locally contains significant amounts of chalcopyrite, covellite, and bornite. The deposit contains 0.3 percent copper with gold values of about 1 gram per tonne. The presence of copper and gold may indicate that this deposit formed near a vent (Kulas, 1992).
The Aqqaluk ore body was discovered north of the main deposit across Red Dog Creek during a drilling program in 1995. The ore is similar to that at the Main deposit. Sphalerite and galena occur in silica rock, barite and shale. Sulfides are disseminated, semi-massive to massive, and rarely laminated. Late crosscutting sulfide veins and stringers occur in the host shale and occasionally in the exhalites.
The Paalaaq ore body is the newest and deepest exploration target in the Red Dog complex.
Kelley, Leach and others (2004) suggest that the mineralization took place by: 1) deposition of early brown sphalerite with abundant barite, minor pyrite, and trace galena immediately beneath the sea floor in unconsolidated mud; 2) deposition of yellow-brown sphalerite during subsea-floor hydrothermal recrystallization and coarsening of preexisting barite; 3) open-space deposition of barite, red-brown sphalerite and other sulfides in veins, and coeval replacement of barite; and 4) post-ore sulfide deposition, including the formation of late tan sphalerite breccias. Sedimentological, faunal, and geochemical data indicate that the Kuna Formation formed in slope and basin settings characterized by anoxic or dyosoxic bottom water (Dumoulin and others, 2004). The mineralization has been dated at 338 Ma by Re-Os methods but has been subject to later thermal overprinting during episodes of the Brooks Range orogeny (Romback and Layer, 2004).
Mineralization at Red Dog was first reported in 1968 by the U.S. Geological Survey (Tailleur, 1970). In 1975, the U.S. Bureau of Mines conducted a mineral examination of the Red Dog site. Active exploration of the site and adjacent area began in 1975 and the first claims were staked in 1978. In 1980, Cominco Alaska drilled 9 holes that totaled 915 meters; extensive surface mapping, sampling, and geochemical and geophysical surveys followed through the the 1980s. Mining began in 1989 from an open pit that is still in operation in early 2011. However, the main ore body of the Red Dog mine will be exhausted within a few years and mining has shifted to the Aqqaluk ore body where mining began in 2011 (Nana Regional Corp, 2011). The mine was developed under an innovative operating agreement between the NANA Regional Corporation, owned by the Inupiat people of Northwest Alaska, and Teck Alaska Incorporated, a U.S. subsidiary of Teck Resources Limited (Nana Regional Corp., 2011).
The mine has been in operation continually since 1989 and from 1999 to 2009 it has produced from about 3.2 to 3.7 tons of ore a year. The production in 2009 was 3.729 million tons of ore that recovered 642,096 tons of zinc, 144,954 tons of lead, and 8.12 million ounces of silver (Szumigala and others, 2010).
As of December, 2009, the Red Dog mine has: 1) 10.14 million tons of proven reserves with a grade of 20.0 percent zinc and 5.4 percent lead; 2) 57.52 tons of probable reserves with a grade of 16.6 percent zinc and 4.4 percent lead; 3) 6.50 million tons of indicated resources with a grade of 20.0 percent zinc and 6.6 per lead; and 4) 34.16 million tons of inferred resources with a grade of 11.0 percent zinc and 4.0 percent lead (Szumigala and others, 2010). The 2009 probable reserves are almost entirely in the Aqqaluk ore body whose 2011 reserves are 51.6 million tons with a grade of 16.7 percent zinc, and 4.4 percent lead (Nana Regional Corp., 2011). This Aqqaluk ore is thought to prolong the life of the mine to 2031. Red Dog indicated mineral resources as of December 31, 2006 for the Aqqaluk deposit are 3.0 million tonnes at 11.2 percent zinc, 4.0 percent lead, and 85 grams of silver per tonne and for the Qanaiyaq deposit indicated resources are 4.7 million tonnes at 23.7 percent zinc, 6.2 percent lead, and 127 grams of silver per tonne (Cinits and others, 2007).
Mining began in 1989 from an open pit called Red Dog Main pit; this was in operation until the first quarter of 2012, when it was exhausted. All future ore will come from the Aqqaluk deposit (Teck, 2014a). The mine life of the Aqqaluk deposit is expected to go through 2031. The Qanaiyaq deposit is higher grade than Aqqaluk and will supplement declining grades in later years from Aqqaluk with an expected mine life from 2016 to 2025 (Cinits and others, 2007).
In 2016, Teck Alaska Inc. mined the Aqqaluk deposit portion of their Red Dog deposit; zinc production increased to 583,000 tonnes compared with 567,000 tonnes in 2015, primarily due to increased mill throughput as softer ores were processed. The zinc grade was 17.1 percent, with an 82.8 percent recovery rate. Lead production in 2016 rose to 122,300 tonnes, compared to 117,600 tonnes in 2015, primarily due to higher mill throughput. The lead grade was 4.9 percent, with a 56.0 percent recovery rate. In 2016, Teck Alaska Inc. mined 13,704,000 tonnes of material and milled 4,250,000 tonnes of ore. In 2016, Teck began development of its Qanaiyaq deposit, a near-surface deposit located immediately south of the mined-out Red Dog Main pit. This high-grade deposit hosts 7.4 million tonnes of reserves averaging 24.7 percent Zn and 6.9 percent Pb; production at Qanaiyaq is scheduled to begin in early 2017 (Athey and Werdon, 2017).
Geologic map unit (-162.840853100136, 68.069748923958)
Mineral deposit model Sedimentary exhalative Zn-Pb (Cox and Singer, 1986; model 31a).
Mineral deposit model number 31a
Age of mineralization Mineralization is syngenetic to sediment deposition which has been dated to 338 Ma by Re-Os methods (Kelley, Leach, and others, 2004).
Alteration of deposit Silicification of host mudstone (Kelley, Leach, and others, 2004).

Production and reserves

Workings or exploration
Mineralization at Red Dog was first reported in 1968 by the U.S. Geological Survey (Tailleur,1970). In 1975, the U.S. Bureau of Mines conducted a mineral examination of the Red Dog site. Active exploration of the site and adjacent area began in 1975 and the first claims were staked in 1978. In 1980, Cominco Alaska drilled 9 holes that totaled 915 meters; extensive surface mapping, sampling, geochemical and geophysical surveys, and much additional drilling followed through the 1980s. Teck has been conducting ongoing exploration work, including geological mapping, geochemistry, geophysical surveys, and drilling, around the Red Dog Property except for a hiatus between 1990 and 1994. Various geophysical survey methods have been used including airborne electromagnetics (EM), induced polarization (IP), controlled source, audio-frequency magneto-tellurics (CSAMT), time-domain electromagnetics (TEM), University of Toronto electromagnetometer (UTEM), and gravity. The discovery of the Anarraaq deposit was attributed to the use of gravity (Cinits and others, 2007).
Mining began in 1989 from an open pit called Red Dog Main pit; this was in operation until the first quarter of 2012, when it was exhausted. All future ore will come from the Aqqaluk deposit (Teck, 2014a). The mine life of the Aqqaluk deposit is expected to go through 2031. The Qanaiyaq deposit is higher grade than Aqqaluk and will supplement declining grades in later years from Aqqaluk with an expected mine life from 2016 to 2025. Red Dog indicated mineral resources as of December 31, 2006 for the Aqqaluk deposit are 3.0 million tonnes at 11.2 percent zinc, 4.0 percent lead, and 85 grams of silver per tonne and for the Qanaiyaq deposit indicated resources are 4.7 million tonnes at 23.7 percent zinc, 6.2 percent lead, and 127 grams of silver per tonne (Cinits and others, 2007).
Teck Alaska Inc. continued to explore on their Noatak project near its’ existing Red Dog mine in northwest Alaska in 2016. The project area includes the Anarraaq-Aktigiruq deposits, where Teck Alaska Inc. drilled a total of 29,800 feet (9,083m) (Athey and Werdon, 2017).
Indication of production Yes; large
Reserve estimates
As of December, 2009, the Red Dog mine has 1) 10.14 million tons of proven reserves with a grade of 20.0 percent zinc and 5.4 percent lead; 2) 57.52 tons of probable reserves with a grade of 16.6 percent zinc and 4.4 percent lead; 3) 6.50 million tons of indicated resources with a grade of 20.0 percent zinc and 6.6 per lead; and 4) 34.16 million ton of inferred resources with a grade of 11.0 percent zinc and 4.0 percent lead (Szumigala and others, 2010). The 2009 probable reserves are almost entirely in the Aqqaluk ore body, whose 2011 reserves are 51.6 million tons with a grade of 16.7 percent zinc, and 4.4 percent lead (Nana Regional Corp., 2011). This Aqqaluk ore is thought to prolong the life of the mine to 2031.
In 2016, Teck Alaska Inc. began development of its Qanaiyaq deposit, a near-surface deposit located immediately south of the mined-out Red Dog Main pit. This high-grade deposit hosts 7.4 million tonnes of reserves averaging 24.7 percent Zn and 6.9 percent Pb; production at Qanaiyaq is scheduled to begin in early 2017. As of March 2016, total Red Dog proven and probable reserves are 56.6 million tonnes at 14.6 percent zinc and 4.1 percent Pb. Indicated resources include 200,000 tonnes at 11.5 percent zinc and 3.8 percent lead (Teck Alaska Inc., 2016).
Production notes
The mine was developed under an innovative operating agreement between the NANA Regional Corporation, owned by the Inupiat people of Northwest Alaska, and Teck Alaska Incorporated, a U.S. subsidiary of Teck Resources Limited (Nana Regional Corp., 2011). The mine has been in operation continually since 1989 and from 1999 to 2009, it has produced from about 3.2 to 3.7 million tons of ore a year. However, the main ore body of the Red Dog mine will be exhausted in a few years and mining has shifted to the Aqqaluk ore body, where mining began in 2011 (Nana Regional Corp., 2011). The production in 2009 was 3.729 million tons of ore that recovered 642,096 tons of zinc, 144,954 tons of lead, and 8.12 million ounces of silver (Szumigala and others, 2010).
The production in 2011 was 572,000 tonnes zinc concentrate (Teck, 2013). The production in 2012 was 529,000 tonnes zinc concentrate at 18.2 percent zinc and 96,700 tonnes lead concentrate at 3.9 percent lead. The production in 2013 was 551,000 tonnes of zinc concentrate at 17.0 percent zinc and 95,400 tonnes lead concentrate at 4.6 percent lead (Teck, 2014b).
In 2016, Teck Alaska Inc. mined the Aqqaluk deposit portion of their Red Dog deposit; zinc production increased to 583,000 tonnes compared with 567,000 tonnes in 2015, primarily due to increased mill throughput as softer ores were processed. The zinc grade was 17.1 percent, with an 82.8 percent recovery rate. Lead production in 2016 rose to 122,300 tonnes, compared to 117,600 tonnes in 2015, primarily due to higher mill throughput. The lead grade was 4.9 percent, with a 56.0 percent recovery rate. In 2016, Teck Alaska Inc. mined 13,704,000 tonnes of material and milled 4,250,000 tonnes of ore. In 2016, Teck began development of its Qanaiyaq deposit, a near-surface deposit located immediately south of the mined-out Red Dog Main pit. This high-grade deposit hosts 7.4 million tonnes of reserves averaging 24.7 percent Zn and 6.9 percent Pb; production at Qanaiyaq is scheduled to begin in early 2017 (Athey and Werdon, 2017).

References

MRDS Number A015690

References

Ayuso, R.A., Kelley, K.D., Leach, D.L., Young, L.E., Slack, J.F., Wandless, J.F., Lyon, A.M., and Dillingham, J.L., 2004, Origin of the Red Dog Zn-Pb-Ag Deposits, Brooks Range, Alaska: Evidence from Regional Pb and Sr Isotope Sources: Economic Geology, v. 99, p. 1533-1553.
Johnson, C.A., Kelley, K.D., and Leach, D.L., 2004, Sulfur and Oxygen Isotopes in Barite Deposits of the Western Brooks Range, Alaska, and Implications for the Origin of the Red Dog Massive Sulfide Deposits: Economic Geology, v. 99, p. 1435-1448.
Kelley, K.D., Leach, D.L., Johnson, C.A., Clark, J.L., Fayek, M., Slack, J.F., Anderson, V.M., Ayuso, R.A., and Ridley, W.I., 2004,Textural, Compositional, and Sulfur Isotope Variations of Sulfide Minerals in the Red Dog Zn-Pb-Ag Deposits, Brooks Range, Alaska: Implications for Ore Formation: Economic Geology, v. 99, p. 1509-1532.
Lewchuk. M.T., Foucher, Jamie, and Elmore, R.D., 2004, Paleomagnetism of the Mesozoic Asik Mountain Mafic Complex in Northern Alaska: Implications for the Tectonic History of the Arctic Composite Terrane: Economic Geology v. 99, p. 1345-1354.
Lewchuk, M.T., Leach, D.L., Kelley, K.D., and Symons, D.T.A., 2004, Paleomagnetism of the Red Dog Zn-Pb Massive Sulfide Deposit in Northern Alaska: Economic Geology, v. 99, p. 1555-1567.
Morelli, R.M., Creaser, R.A., Selby, D., Kelley, K.D., Leach, D.L., and King, A.R., 2004, Re-Os Sulfide Geochronology of the Red Dog Sediment-Hosted Zn-Pb-Ag Deposit, Brooks Range, Alaska: Economic Geology, v. 99, p. 1569-1576.
Slack, J.F., Kelley, K.D., Anderson, V.M., Clark, J.L., and Ayuso, R.A., 2004, Multistage Hydrothermal Silicification and Fe-Tl-As-Sb-Ge-REE Enrichment in the Red Dog Zn-Pb-Ag District, Northern Alaska: Geochemistry, Origin, and Exploration Applications: Economic Geology, v. 99, p. 1481-1508.
Teck, 2013, Resourceful Teck 2013 Annual Report: http://www.teck.com/res/tc/documents/_ces_portal_meta/downloads/investors/2013%20annual%20report/teck%202013%20annual%20report.pdf (as of July 15, 2014).
Teck, 2014a, Annual Information Form, March 3, 2014: http://teck.com/res/tc/documents/_ces_portal_meta/downloads/investors/annual%20information%20form/aif%20march%202014.pdf (as of July 15, 2014).
Teck, 2014b, Red Dog Operating Results: http://www.teck.com/Generic.aspx?PAGE=Teck+Site%2fDiversified+Mining+Pages%2fZinc+Pages%2fRed+Dog+Mine+Pages%2fProduction&portalName=tc (as of December 1, 2014).
Werdon, M.B., Layer, P.W., and Newberry, R.J., 2004, 40Ar/39Ar Dating of Zn-Pb-Ag Mineralization in the Northern Brooks Range, Alaska: Economic Geology v. 99, p. 1323-1343.
Reporters Anita Williams (Anchorage, AK); Travis L. Hudson (Applied Geology, Inc.); D.J. Grybeck (Contractor, USGS); V.C. Zinno (Alaska Earth Sciences, Inc.); M.B. Werdon (DGGS)
Last report date 8/26/2017