Unnamed Occurrence (ARDF - MH315; west of Powell Gulch northeast of peak 5950), Chistochina Mining District, Southeast Fairbanks Census Area, Alaska, USAi

Regional Level Types
Unnamed Occurrence (ARDF - MH315; west of Powell Gulch northeast of peak 5950)	- not defined -
Chistochina Mining District	Mining District
Southeast Fairbanks Census Area	Census Area
Alaska	State
USA	Country

Location: The occurrence is near the top of the ridge south of Slate Creek and west of Powell Gulch. It is a few hundred feet northeast of peak 5950. The occurrence is in the SW1/4NW1/4 section 27, T. 20 S., R. 15 E., Fairbanks Meridian. It corresponds to locality 27 of Rose (1967), locality 19 on figure 6 of Cobb (1979 [OFR 79-239]), and locality 137 in table 2 of Nokleberg and others (1991). The location is accurate within 0.1 mile.
Geology: The rocks near peak 5950 are mainly Tetelna Volcanics of Pennsylvanian age (Richter and Dutro, 1975), previously mapped as Chisna Formation of Pennsylvanian and Permian (?) age (Rose, 1967). Intrusions of quartz monzonite and the Gakona diorite of Mesozoic age occur in the vicinity. Locally, the volcanic rocks contain secondary epidote and have been chloritized and pyritized and contain disseminated chalcopyrite. Nokleberg and others (1991, table 2) collected a grab sample from a zone about 10 feet wide and 30 feet long that assayed 1.4 percent copper and 15 parts per million silver. A select sample from a chalcopyrite-bearing boulder assayed a trace of gold, 0.52 ounce of silver per ton and 1.14 percent copper (Rose, 1967).
Workings: Limited surface sampling.
Age: Probably Mesozoic, related to nearby intrusions of quartz monzonite and Gakona diorite (Rose, 1967).
Alteration: Sulfidization of Pennsylvanian volcanic rocks; introduction of chlorite and epidote.

Commodities (Major) - Cu; (Minor) - Ag, Au
Development Status: No
Deposit Model: Cu skarn or Porphyry Cu, distal (Cox and Singer, 1986; model 18B, model 20c).

Other Databases

Link to USGS - Alaska:	MH315

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References