Geroe Creek; MAS claims Prospect, Chandalar Mining District, Yukon-Koyukuk Census Area, Alaska, USAi

Regional Level Types
Geroe Creek; MAS claims Prospect	Prospect
Chandalar Mining District	Mining District
Yukon-Koyukuk Census Area	Census Area
Alaska	State
USA	Country

See also: Venus (CH065), Victor (CH064), Eva (CH063) and Evelyn Lee (CH059) prospects; Alaska Kardex No. 031-68 (Kardex is a card file mining claim information system located at the State of Alaska DNR Public Information Center in Fairbanks).
Location: The reference point is at an elevation of 5,500 feet, near the divide between Geroe Creek and Willow Creek (NW1/4 sec. 24, T. 33 N., R. 6 W., of the Fairbanks Meridian) and at the center of a large claim block (239 claims). A second large claim block northeast of of the Geroe property, and contiguous with its northeast corner (U.S. Bureau of Mines, 1973), may be part of this large property. The location is accurate within a 1-mile radius.
Geology: The Geroe Creek prospect is one of several quartz stockworks and altered zones in the northeast-trending belt of Devonian peraluminous biotite-muscovite granites of the Baby Creek batholith and the Devonian metaluminous biotite-hornblende granites and granodiorites of the Horace Mountain plutons (Newberry and others, 1986). Porphyritic phases are locally present in these plutons, and Young and others (1997) reported that the mineralizing intrusives are porphyritic meta-granodiorites and biotite meta-granites. The country rocks are mainly Paleozoic schists and marble along with peraluminous meta-granodiorite. Young and others (1997) also noted that there is no skarn development in the calcareous rocks. The veinlets in the stockworks on the Geroe prospect contain disseminated molybdenite, chalcopyrite, and pyrite along with intense quartz-sericite-chlorite plus or minus epidote alteration. Eakins and others (1983, p. 41) reported Mo grades as much as 0.1 percent, and Nokleberg and others (1987) report that zones in the plutons as much as several meters thick contain values of 0.6 percent Cu, 0.02 percent Mo, and 0.1 grams of gold per ton.
Workings: 239 claims staked in 1975 and 1976.
Age: Devonian(?) based on reported Early Devonian Pb/Pb zircon ages from the associated Baby Creek batholith and Horace Mountain plutons (Dillon and others, 1996).
Alteration: Seritization and propylitization of porphyritic host rocks; quartz-sericite-chlorite plus or minus epidote; calcite.

Commodities (Major) - Cu, Mo
Development Status: None
Deposit Model: Porphyry Cu-Mo (Cox and Singer, 1986; model 21a)

Other Databases

Link to USGS - Alaska:	CH053

Other Regions, Features and Areas containing this locality

References