Billiken

Prospect, Active

Alternative names

Kugruk

Commodities and mineralogy

Geographic location

Quadrangle map, 1:250,000-scale BN
Quadrangle map, 1:63,360-scale C-1
Latitude 65.69
Longitude -162.4931
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Billiken prospect is about 1.4 miles northwest of the junction of Independence Creek and the Kugruk River. It is at an elevation of about 580 feet near the center of section 6, T. 3 N., R. 18 W. The location is accurate.

Geologic setting

Geologic description

This magnetite-rich skarn prospect was discovered and core drilled by Placid Oil and Minerals in the mid-1970s. Although tundra cover is extensive in this area, the deposit is well expressed in aeromagnetic data. A large, positive, north-south trending aeromagnetic anomaly over this prospect is about 0.4 mile wide and 2 miles long. The deposit contains massive to brecciated magnetite, with blebs to stringers of pyrite and chalcopyrite, in dolomite (Hudson and others, 1977). Newberry and others (1997) classify it as a magnesian-iron skarn developed in dolomite. It contains clinohumite, olivine, diopside, and idocrase. Serpentine minerals replace diopside, and olivine and phlogopite are present. A sample of the skarn contained 0.06 ounce of silver per ton, 0.0003 ounce of gold per ton, 0.2 percent copper, 0.02 percent zinc, 0.01 percent cobalt, and 45 percent iron (Newberry and others, 1997). This deposit is in the east contact zone of the Kugruk pluton, which has a K/Ar age of 94.9 +/- 2.9 Ma (Till and others, 1986, p. A-15).
In 2005, NovaGold began staking a large block of claims that eventually covered much of the basin of the Kugruk River and its tributaries (TintinaGold Resources Inc., 2010 [prospect]). In their extensive regional work, they collected about 2000 soil samples over the Kugruk pluton and the mineralized area of the Billiken prospect. TintinaGold Resources Inc. acquired the property in the spring of 2009. Their 2009 work included ground and aerial surveys, geochemical sampling, geologic mapping, and prospect evaluation. They particularly noted a north-trending belt, up to 2.1 miles wide and 7.5 miles long, of strong geophysical anomalies and copper anomalies in soil on the east side of the Kugruk pluton. The Billiken prospect is in this belt.
TintinaGold drilled three holes near the Billiken prospect in 2010 to test a large magnetic high, coincident with a resistivity low, gravity high, and IP chargeability high (Chutas and Robinson, 2010; TintinaGold, 2010 (drill results]). The first hole went through a zone more than 50 meters thick of massive magnetite with calc-silicate alteration and copper mineralization. The other holes intersected additional zones of copper mineralization associated with magnetite-rich calc-silicate alteration. Chalcopyrite is the primary copper mineral; in some magnetite-rich zones, it is accompanied by pyrite, pyrrhotite, and traces of sphalerite and galena. The alteration assemblages commonly contain pyroxene, garnet, magnetite, scapolite, and locally retrograde chlorite, actinolite, and epidote. Some notable intercepts in the 2010 drilling were: 22 meters with 0.44 percent copper and 49.0 percent iron, and 31.2 meters with 1.70 percent copper, 21.7 percent iron, 0.604 gram of gold per tonne, and 18.6 grams of silver per tonne.
Geologic map unit (-162.495775621644, 65.6893105321097)
Mineral deposit model Magnesian-iron skarn (Newberry and others, 1997; Cox and Singer, 1986; model 18d).
Mineral deposit model number 18d
Age of mineralization Cretaceous; this deposit is probably related to the nearby 94.9 +/- 2.9 Ma pluton (Till and others, 1986, p. A-15).
Alteration of deposit Mg-bearing skarn developed adjacent to a Cretaceous pluton.

Production and reserves

Workings or exploration The prospect was initially explored by Placid Oil by core drilling in the 1970s. Beginning in 2005, NovaGold began staking a large block of claims that eventually covered much of the basin of the Kugruk River and its tributaries (TintinaGold Resources Inc., 2010 [prospect]). In their extensive regional work, they collected about 2,000 soil samples over the Kugruk pluton and the mineralized area of the Billiken prospect. TintinaGold Resources Inc. acquired the property in the spring of 2009. Their 2009 work included both ground and aerial surveys, geochemical sampling, geologic mapping, and prospect evaluation. Tintina Gold drilled 3 holes in 2010.
Indication of production None
Reserve estimates None.
Production notes None.

Additional comments

None.

References

MRDS Number A012684

References

Newberry, R.J., Allegro, G.L., Cutler, S.E., Hagen-Levelle, D.D., Adams, D.D., Nicholson, L.C., Weglarz, T.B., Bakke, A.A., Clautice, K.H., Coulter, G.A., Ford, M.J., Myers, G.L., and Szumigala, D.J., 1997, Skarn deposits of Alaska, in Goldfarb, R.J., and Miller, L.D., eds., Mineral Deposits of Alaska: Economic Geology Monograph 9, p. 355-395.
TintinaGold Resources Co., 2010, TintinaGold releases initial drill results from Kugruk copper-gold-silver-iron project, Alaska: http://tintinagold.com/Images/1785TAU-NR%20and%20figures%20-%20Jul-19-10-Final.pdf (News release, July 19, 2010).
TintinaGold Resources Inc., 2010, Kugruk prospect: http://www.mantramining.com/Kugruk_Prospect.aspx?m_id=2712 (as of February 1, 2010)
Reporters Travis L. Hudson (Applied Geology); D.J. Grybeck (Contractor, USGS)
Last report date 2/28/2011