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Eneveloe (Bonanza

Prospect in Alaska, United States with commodities Gold, Silver, Copper, Lead, Antimony, Zinc
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Sections on this page
  1. Identification information
  2. Geographic coordinates
  3. Site location context
  4. Geographic areas
  5. Commodities
  6. Materials information
  7. Mineral occurrence model information
  8. Host and associated rocks
  9. Nearby scientific data
  10. Economic information about the deposit and operations
  11. Mining district
  12. Links to other databases
  13. Bibliographic references
  14. General comments
  15. Reporter information

Geologic information

Identification information

Deposit ID 10001766
MRDS ID A012554
Record type Site
Current site name Eneveloe (Bonanza
Alternate or previous names Jupiter, Woodchuck, Venus, Golden Eagle, First Chance, Last Chance, Envelope)

Geographic coordinates

Geographic coordinates: -148.20329, 67.53974 (WGS84)
Relative position This site is at an elevation of about 4,700 ft, approximately 3 1/2 miles south of Squaw Lake and 1/4 mile south of Little Squaw Peak (NW1/4 sec. 3, 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, are considered to constitute the Eneveloe property. The location is accurate a within 1/4-mile radius.

Site location context

Political divisions (FIPS codes)

Yukon-Koyukuk(Census area)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Chandalar C-3(quadrangle 1:63,360 scale)

Chandalar N(quadrangle 1:100,000 scale)

Chandalar C(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Alaska(hydrologic region)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Gold Primary
Silver Secondary
Copper Secondary
Lead Secondary
Antimony Critical Secondary
Zinc Critical Secondary

Materials information

Materials Type of material
Galena Ore
Gold Ore
Scorodite Ore
Quartz Gangue

Mineral occurrence model information

Model code 273
USGS model code 36a
Deposit model name Low-sulfide Au-quartz vein
Mark3 model number 27

Host and associated rocks

  • Host or associated Host
    Rock type
    Stratigraphic age (youngest) Devonian

Nearby scientific data

(1) -148.20329, 67.53974
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = 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 oz of gold). 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 lying 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. Most of the quartz veins in the district are discontinuous along the structures, generally pinching out within a few hundred feet or less. Widths may 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).
  • 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.
  • Age = Host rock is Devonian.

Economic information about the deposit and operations

Development status Prospect
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Chandalar

Comments on the workings information

  • Workings / Exploration = Surface and underground workings include an adit 165 feet in length driven before 1913 between the First Chance and Last Chance claims that extend along the vein to a depth of 40 feet (Maddren, 1913). Another adit was opened on the Woodchuck claim, but there is no description of its extent. The property has also been explored along 1,000 feet of its length by open cuts and other shallow workings.

Reference information

Bibliographic references

Comments on the references

  • Primary Reference = Chipp, 1970

General comments

Subject category Comment text
Deposit Model Name = Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a)
Deposit Other Comments = 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, and the Venus claims on U.S. Mineral Survey 1630.

Reporter information

Type Date Name Affiliation Comment
Reporter 17-NOV-99 J.M. Britton U.S. Geological Survey

Beyond USGS

Supplemental information added by qvyshift.com. Not part of the original USGS MRDS record.

Maps centered on this site

Authoritative Alaska resources

These are landing pages for further research — the state agencies don't currently expose per-mine deep links.