Eneveloe Prospect (Bonanza; Jupiter; Woodchuck; Venus; Golden Eagle; First Chance; Last Chance; Envelope), Chandalar Mining District, Yukon-Koyukuk Census Area, Alaska, USAi

Regional Level Types
Eneveloe Prospect (Bonanza; Jupiter; Woodchuck; Venus; Golden Eagle; First Chance; Last Chance; Envelope)	Prospect
Chandalar Mining District	Mining District
Yukon-Koyukuk Census Area	Census Area
Alaska	State
USA	Country

See also: Summit (CH041), Star (CH042), Mikado (CH045), Little Squaw (CH040). The Eneveloe claim, along with the Bonanza and Golden Eagle, are shown on U.S. Mineral Survey 1995. The Jupiter and Woodchuck claims are shown on U.S. Mineral Survey 1629. The Venus claims are shown on U.S. Mineral Survey 1630.
Location: The Eneveloe prospect is at an elevation of about 4,700 feet, approximately 3 1/2 miles south of Squaw Lake and 1/4 mile south of Little Squaw Peak. in the SE1/4 section 4, T. 31 N., R. 3 W., of the Fairbanks Meridian. Chipp (1970) described the location of the Eneveloe and Bonanza claims as being north of the Summit mine area (which is on the south side of the saddle just south of Little Squaw Peak) and south of Little Squaw Peak. Mineral surveys show six patented claims (Eneveloe, Bonanza, Golden Eagle, Jupiter, Woodchuck, and Venus), and these, along with the presumably unpatented First Chance and Last Chance claims which are not shown on the mineral survey, constitute the Eneveloe property. The location is accurate.
Geology: The surface and underground workings on the Eneveloe prospect extend along the vein to a depth of 40 feet; they include an adit 165 feet in length driven before 1913 between the First Chance and Last Chance claims (Maddren, 1913). Another adit was opened on the Woodchuck claim, but there is no description of its extent. The property has also been explored for 1,000 feet along strike by open cuts and other shallow workings. In 2004, Little Squaw Gold Mining Company controlled 8,550 acres of patented and unpatented mining claims in the Chandalar district which includes the Eneveloe prospect. This company contracted a district-scale analysis of the placer and lode gold potential of the district by Pacific Rim Geological Consulting, Inc. This study was completed in April, 2004 (Barker and Bundtzen, 2004). The Eneveloe lode consists of discontinuous quartz veins 4 to 6 feet wide, at least one of which carries free gold. According to Maddren (1913) a sample from a surface outcrop on the Last Chance claim assayed $198 (approximately 9.6 ounces of gold per ton). Prospect pits on the Jupiter claim, located along the Summit fault west of the Summit mine, exposed quartz containing minor arsenopyrite and scorodite. In the area of the Eneveloe and Bonanza claims, minor quartz veins crop out and prospect pits expose small and discontinuous quartz veins containing minor galena and scorodite. The veins are traceable for 1,500 feet and generally dip steeply south. The Eneveloe lode is one of several gold-bearing quartz veins in the Chandalar district, an area approximately 1 mile wide and 2 1/2 miles long between the heads of Big, Tobin, Squaw and Little Squaw creeks. The principal deposits in this area are localized along three steeply dipping, northwest-trending normal faults in Devonian quartz-muscovite schist, phyllite and quartzite, intruded by Devonian mafic sills and dikes (Chipp, 1970). The mafic intrusions have been metamorphosed to greenstone or greenschist. From north to south these normal faults are the Little Squaw, Summit, and Mikado. The Eneveloe property is along the Summit fault a short distance west of the Summit mine (CH041). Most of the quartz veins in the district are discontinuous along the structures, generally pinching out within a few hundred feet or less. Widths vary from a few inches to several feet but are generally less than 10 feet. The quartz veins exhibit evidence of shearing, which indicates that the veins were emplaced before or during fault movement. Sulfide content of the veins is typically less than 5 percent, with the primary sulfides being, in relative order of abundance, arsenopyrite, galena, sphalerite, and pyrite. Much of the gold occurs as native gold. Weathering near the surface has oxidized and leached the sulfides to produce scorodite and limonite. The genesis of these gold deposits is still in question, although various authors have hypothesized genetic links to a variety of felsic and mafic igneous rocks from which the gold was remobilized during metamorphism (Mertie, 1925; Boadway, 1933; Chipp, 1970; Dillon, 1982).
Workings: The surface and underground workings on the Eneveloe prospect extend along the vein to a depth of 40 feet; they include an adit 165 feet in length driven before 1913 between the First Chance and Last Chance claims (Maddren, 1913). Another adit was opened on the Woodchuck claim, but there is no description of its extent. The property has also been explored for 1,000 feet along strike by open cuts and other shallow workings. In 2004, Little Squaw Gold Mining Company controlled 8,550 acres of patented and unpatented mining claims in the Chandalar district which includes the Eneveloe prospect. This company contracted a district-scale analysis of the placer and lode gold potential of the district by Pacific Rim Geological Consulting, Inc. This study was completed in April, 2004 (Barker and Bundtzen, 2004).
Age: Middle Cretaceous(?) based on arguments by Dillon (1982) that the age of emplacement of the gold-bearing quartz veins of the Koyukuk and Chandalar districts was between the Neocomian metamorphism of the Devonian host rocks and their erosional unroofing and cooling in Albian time.

Commodities (Major) - Au; (Minor) - Ag, Cu, Pb, Sb, Zn
Development Status: Undetermined
Deposit Model: Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a)

Other Databases

Link to USGS - Alaska:	CH046

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References