Boomerang

Prospect, Active

Commodities and mineralogy

Main commodities Au
Other commodities As; Bi; Cu; Sb; Zn

Geographic location

Quadrangle map, 1:250,000-scale TN
Quadrangle map, 1:63,360-scale B-3
Latitude 65.30136
Longitude -151.37344
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Boomerang lode prospect is just north of the Yukon River, northwest of Manley Hot Springs, in the Morelock Creek area. The exact location of the Boomerang prospect has not been made public. At least part of it reportedly is in section 36, T. 6 N., R. 19 W., of the Fairbanks Meridian (North Star Exploration, Inc., 2000 [DLR2000-17]). For this record, the site is on a ridge at an elevation of about 2,200 feet in the southwest quarter of section 36.

Geologic setting

Geologic description

Bedrock in the Boomerang prospect area consists of Cretaceous or Lower Tertiary quartz monzonite (Chapman and others, 1982) or granite (Wilson and others, 1998) that comprises two phases, one unaltered, the other altered. The country rocks are Devonian marble and Upper Proterozoic (?) or Paleozoic pelitic and quartzitic schist (Wilson and others, 1998).
North Star Exploration, Inc. (2000 [DLR2000-17]; 2000 [Reduced calcic gold skarns]) has produced a simplified, small-scale geologic map of the Boomerang prospect. In addition to ground work, the company has conducted a helicopter-borne, magnetic-EM-radiometric survey of the area. The survey defined three strong, circular magnetic anomalies associated with moderate to strong conductors (North Star Exploration, Inc., 2000 [Highly mineralized block 20]. There are abundant carbonate strata in the area, and there is a nearby intrusion. At least one conductive geophysical anomaly corresponds to copper-bearing boulders in a stream bed (North Star Exploration, Inc., 2000 [Highly mineralized block 20]. North Star has proposed that this area is the potential site of a reduced calcic gold skarn deposit, an interpretation supported by their geological, geochemical, and geophysical data. The closest historic gold placer mining was approximately one mile to the north, in Homestake Creek (TN028).
The Alaska Division of Geological and Geophysical Surveys studied the Boomerang prospect area in 1992 as part of a mineral resource evaluation of State-selected lands. A rock sample (station 92RE2042) of calcareous biotite schist contained 4,708 parts per million (ppm) manganese, 26 ppm tin, and 297 ppm zinc (Solie and others, 1993).
Geologic map unit (-151.375954791284, 65.3008552974293)
Mineral deposit model Copper-gold skarn (after Cox and Singer, 1986; model 18b) or Porphyry copper-gold (after Cox and Singer, 1986; model 20c).
Mineral deposit model number 18b or 20c
Age of mineralization Presumably Cretaceous or younger, the age of the intrusive rocks.
Alteration of deposit Unspecified alteration of the granitic rocks.

Production and reserves

Workings or exploration
In 1998-99, North Star Exploration, Inc., conducted a magnetic-EM-radiometric survey over much of the prospect area. Surface exploration identified several geochemical anomalies and copper-bearing boulders in a stream bed (North Star Exploration, Inc., 2000 [Highly mineralized block 20].
North Star Exploration, Inc., identified the Boomerang prospect as a priority target in the late 1990s, based on compilation and interpretation of regional and detailed geological, geophysical, geochemical, and Landsat data. Included in their compilation are proprietary and public-domain, helicopter-borne magnetic/resistivity/EM (electromagnetic) geophysical surveys that the company is using to identify of skarn targets (North Star Exploration, Inc., 2000 [Reduced calcic gold skarns]).
The Alaska Division of Geological and Geophysical Surveys studied the Boomerang prospect area in 1992 as part of a mineral resource evaluation of State-selected lands. A rock sample (station 92RE2042) of calcareous biotite schist contained 4,708 parts per million (ppm) manganese, 26 ppm tin, and 297 ppm zinc (Solie and others, 1993).
Indication of production None

Additional comments

This site is on land selected by or conveyed to Doyon, Ltd. For further information, contact Doyon, Ltd., at 1 Doyon Place, Suite 300, Fairbanks, Alaska, 99701-2941.

References

References

Reporters G.E. Graham (ADGGS), D.J. Szumigala (ADGGS)
Last report date 4/9/2004