Bond Creek

Prospect, Inactive

Commodities and mineralogy

Main commodities Ag; Au; Cu; Mo
Ore minerals chalcopyrite; gold; molybdenite; pyrite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale NB
Quadrangle map, 1:63,360-scale A-4
Latitude 62.198
Longitude -142.7027
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is on the ridge between the middle and west forks of Bond Creek. It is at an elevation of about 7,000 feet, 6,000 feet northwest of peak 8485. The prospect is about 0.1 mile west of the center of section 19, T. 5 N., R. 15 E. of the Copper River Meridian. This is locality 3 of Richter (1973), locality 30 of Richter and others (1975), and National Park Service locality WRST-35 (unpublished data). This prospect was included by Cobb and Richter (1980) under the name 'Bond Cr.'. It is located to within a few hundred feet.

Geologic setting

Geologic description

This porphyry copper-molybdenum deposit was discovered in the 1960s and explored by some diamond drilling. Pyrite, chalcopyrite, and minor molybdenite occur in quartz veinlets and as disseminations in highly altered volcanic rocks, quartz diorite, and granodiorite intruded by leucocratic, quartz monzonite (Richter and others, 1975). The host rocks are altered over a 2.5 square kilometer area (Hollister and others, 1975; Richter and Matson, 1970 [OFR 70-276]; Richter, 1973). The alteration includes a 600- by 2,000(?)-meter central zone with abundant chlorite, minor biotite and potassium feldspar, spotty sericite, and late anhydrite veins. A 2,000- by 3,000-meter outer zone has minor chlorite, epidote, and anhydrite. The deposit is estimated to contain 500 million tons with an average grade of 0.30 percent copper and 0.02 percent molybdenum; some gold and silver is also likely (Richter and others, 1975). The host rocks include part of the Paleozoic Tetelna Volcanics, granitic rocks of the mid-Cretaceous Nabesna pluton, and leucocratic, quartz monzonite porphyry (Richter, 1973, 1976; Richter and others, 1975). Dikes, irregular intrusions, and stocks of probably Tertiary, hornblende-plagioclase porphyry intrude the volcanic and granitic host rocks in nearby areas (Richter, 1973).
Geologic map unit (-142.70482826283, 62.1976131994458)
Mineral deposit model Porphyry Cu-Mo (Cox and Singer, 1986; model 21a)
Mineral deposit model number 21a
Age of mineralization Mid-Cretaceous. The intrusive host rocks to the Bond Creek deposit are considered to be part of the Nabesna pluton. K/Ar ages for the Nabesna pluton range from 105 +/- 4.0 to 114 +/- 3.4 Ma (Richter, Lanphere, and Matson, 1975; Richter and others, 1975). Many varieties of probably Tertiary hornblende-plagioclase porphyry form irregular intrusive bodies into the Nabesna pluton and other regional bedrock units in the area (Richter, 1973).
Alteration of deposit The host rocks are altered over a 2.5 square kilometer area (Richter, 1973). The alteration includes a 600- by 2,000(?)-meter central zone with abundant chlorite, minor biotite and potassium feldspar, spotty sericite, and late anhydrite veins. A 2,000- by 3,000-meter outer zone has minor chlorite, epidote, and anhydrite.

Production and reserves

Workings or exploration This porphyry copper-molybdenum deposit was discovered in the 1960s and explored by some diamond drilling.
Indication of production None
Reserve estimates The deposit is estimated to contain 500 million tons with an average grade of 0.30 percent copper and 0.02 percent molybdenum; some gold and silver values are also likely (Richter and others, 1975).

Additional comments

The prospect is in the Wrangell-St. Elias National Preserve.

References

MRDS Number A010705; A0110673; A011403

References

Reporters Travis L. Hudson (Applied Geology)
Last report date 11/24/2002