Unnamed (midpoint of Ingle Creek)

Occurrences, Inactive

Commodities and mineralogy

Main commodities Au; Cu
Ore minerals chalcopyrite; pyrite
Gangue minerals calcite; chlorite; epidote; quartz

Geographic location

Quadrangle map, 1:250,000-scale EA
Quadrangle map, 1:63,360-scale A-3
Latitude 64.0923
Longitude -142.026
Nearby scientific data Find additional scientific data near this location
Location and accuracy These occurrences are located on Ingle Creek, just north of its intersection with Lilliwig Creek. There are two sites with anomalous gold here, and the coordinates are for the southwestern site, in section 26, T. 27 N., R. 17 E., of the Copper River Meridian. This location is accurate. The second site is located about 1,700 feet to the northeast.

Geologic setting

Geologic description

The rocks in the vicinity of Ingle Creek are primarily upper Paleozoic greenschist-facies metasedimentary and metavolcanic rocks that have been intruded by granitic rocks that are either related to the Taylor Mountain batholith of Triassic age to the south or the Chicken pluton of Jurassic age to the north (Werdon and others, 2001). These units have been cut by numerous high-angle faults. In the lower part of Ingle Creek, Tertiary gabbro is overlain by tuffaceous material and sparse shale. Quaternary colluvium and alluvium are present in the lower valley.
There are two sites located about 1,700 feet apart that are included as part of this unnamed occurrence. At the southwestern site, greenstone with a fine-grained gabbroic texture exhibits chlorite-epidote alteration and is cut by veins of pyrite, quartz, calcite, and chalcopyrite. A select sample of one vein assayed 35 ppb gold and 603 ppm copper (Szumigala and others, 2000). At the northeastern site, many rock types are juxtaposed by many high-angle to moderately dipping faults; the rocks include upper Paleozoic greenstone; hypabyssal, feldspar porphyry dikes(?) of probable Jurassic age; highly foliated granitic plutonic rocks that are probably part of the Taylor Mountain batholith; and unfoliated dikes and plugs of Tertiary gabbro (M.B. Werdon, unpub. field mapping, 1999). A 5-foot-wide, highly silicified zone is present along the fault contact between a foliated granitic pluton and a hypabyssal porphyritic felsic rock. The silicified zone is light gray, and contains abundant epidote, pyrite, sprays of chlorite, and calcite occurs along joint surfaces. An assay from this zone contains 30 ppb gold and 197 ppm molybdenum (Szumigala and others, 2000).
Geologic map unit (-142.028280638732, 64.0919704478893)

Production and reserves

Indication of production None

References