Unnamed Occurrence (ARDF - MH026; upper East Fork Susitna River), Valdez Creek Mining District, Matanuska-Susitna Borough, Alaska, USAi

Regional Level Types
Unnamed Occurrence (ARDF - MH026; upper East Fork Susitna River)	- not defined -
Valdez Creek Mining District	Mining District
Matanuska-Susitna Borough	Borough
Alaska	State
USA	Country

The presence of gold particles at several sites (see Geologic description) in the north-side lateral moraine below a glacier in the upper East Fork Susitna River suggests the existence of an upstream bedrock gold source.
Location: This placer occurrence is at an elevation of about 2,800 feet on an unnamed south-flowing tributary of the East Fork Susitna River. The location is accurate; it is in the NW 1/4 of section 3, T. 18 S., R. 4 E., Fairbanks Meridian. The occurrence corresponds to locality A2 of Kurtak and others (1992).
Geology: This gold placer occurrence is in alluvium and lateral moraine cut by a south-flowing tributary of the upper East Fork Susitna River. Two types of unconsolidated material host the gold deposits: one is the alluvium in the south-flowing tributary; the other is lateral moraine derived from a glacier in the East Fork Susitna River about 3 miles above the occurrence and derived from a regionally metamorphosed batholith of Late Cretaceous to Early Tertiary age (Nokleberg and others, 1982). Two gold-bearing samples were collected at the site. Sample 2923 was collected from the alluvial fan at the foot of the south-flowing tributary. At this site, poorly sorted material contained about 0.01 ounce of gold per cubic yard; gold particles ranged from very coarse to very fine. Concentrates from this sample contained pyrite, garnet, and microscopic particles of linnaeite, a cobalt sulfide (Kurtak and others, 1992, p. 83). Sample 2677 collected from lateral moraine contained 10 to 20 very fine particles of gold. Kurtak and others (1992) noted that several localities along the lateral moraine on the north side of the East Fork Susitna River contained gold of unknown source and significance.
Workings: No workings.
Age: Holocene.

Commodities (Major) - Au; (Minor) - Co
Development Status: None
Deposit Model: Placer Au (Cox and Singer, 1986, model 39a).

Other Databases

Link to USGS - Alaska:	MH026

Other Regions, Features and Areas containing this locality

References