Green Wonder Prospect, Delta River Mining District, Southeast Fairbanks Census Area, Alaska, USAi

Regional Level Types
Green Wonder Prospect	Prospect
Delta River Mining District	Mining District
Southeast Fairbanks Census Area	Census Area
Alaska	State
USA	Country

Zinc mineralization at this site is unique in the area between Broxson Gulch and the Rainy Creek area.
Location: The Green Wonder prospect is at an elevation of 4,600 feet, a mile east of the east fork of the stream(s) in Broxson Gulch, and about 1,800 feet southwest of peak 5304 on the boundary between sections 31 and 32, T. 18 S., R. 9 E., Fairbanks Meridian. The prospect corresponds to locality 55 in table 2 of Nokleberg and others (1991), locality 38 on figure 4 of Cobb (1979 [OFR 79-238]), and locality 13 on figure 2 of Rose (1965).
Geology: The Green Wonder prospect is in an amphibolitized serpentine unit in contact with graywacke and meta-andesite of the Slana Spur Formation of Late Paleozoic age (Rose, 1965; Nokleberg and others, 1991). The serpentinized unit is part of the informally named Eureka ultramafic complex of Late Triassic age that is emplaced on strands of the Broxson Gulch thrust fault (W.T. Ellis, unpublished data, 1996). At the prospect site, the altered serpentinite is converted to an almost white, diopside-garnet-quartz skarn. The deposit is a mineralized zone less than a foot wide of a bright green rock composed of sphalerite and uvarovite (a chrome garnet) and minor pyrite. The rock assayed 10 percent or more zinc, 4 percent chrome, and 2 percent nickel (Rose, 1965, p. 29). A 60-foot-wide diabase dike cuts meta-andesite near the Green Wonder prospect site. The dike contains disseminated chalcopyrite. Sample 79IL020C of Nokleberg and others (1991, locality 55, table 2) assayed 0.72 percent copper, 0.3 percent vanadium, and 7 parts per million silver.
Workings: The Green Wonder deposit was located and trenched in 1964 by Moneta-Porcupine Company. The area was subsequently mapped by Rose (1965). The prospect is on active MAN Resources claims.
Age: Late Triassic or younger.
Alteration: Pervasive quartz-garnet-diopside skarn alteration of amphibolitized serpentinite; a sphalerite-uvarovite skarn formed at the Green Wonder mineral locality.

Commodities (Major) - Cu, Zn; (Minor) - Ag, Cr, Cu, Ni, V
Development Status: None
Deposit Model: Skarn affiliated with mafic-ultramafic host rock.

Other Databases

Link to USGS - Alaska:	MH126

Other Regions, Features and Areas containing this locality

References