Summit

Site Name

Primary: Summit

---

Commodity

Primary: Gold
Primary: Silver
Secondary: Antimony
Secondary: Lead
Secondary: Copper

---

Location

State: Alaska
District: Chandalar

---

Land Status

Not available

---

Holdings

Not available

---

Workings

Not available

---

Ownership

Not available

---

Production

Not available

---

Deposit

Record Type: Site
Operation Category: Prospect
Operation Type: Unknown
Years of Production:
Organization:
Significant:

---

Physiography

Not available

---

Mineral Deposit Model

Model Name: Low-sulfide Au-quartz vein

---

Orebody

Not available

---

Structure

Not available

---

Alterations

Alteration Type: L
Alteration Text: Oxidation of vein material produces scorodite and limonite.

---

Rocks

Role: Host
Age Type: Host Rock
Age Young: Devonian

---

Analytical Data

Not available

---

Materials

Ore: Scorodite
Ore: Gold
Ore: Arsenopyrite
Gangue: Quartz

---

Comments

Comment (Geology): Age = Host rock is Devonian.

Comment (Exploration): Status = Inactive

Comment (Workings): Workings / Exploration = Maddren (1913) reported a 54-foot-deep shaft and a 72-foot drift along the vein. Prospect pits have been dug along the Summit fault/vein system as far east as the pass between Big Creek and McClellan Creek and west along the spur going into Big Squaw Creek. Heiner and Wolff (1968) report that there was some development work in the 1950s and a small mill was established for the ore in the headwaters of Big Creek.

Comment (Geology): 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.

Comment (Deposit): Other Comments = See also: Mikado (CH045), Little Squaw(CH040), Star(CH042).

Comment (Geology): Geologic Description = The Summit lode is one of the four principal auriferous quartz vein systems in the Chandalar area. The Summit vein system, like the others in the area, is localized along steeply-dipping, northwest-trending normal faults in Devonian quartz-muscovite schist, phyllite, and quartzite, intruded by Devonian mafic sills and dikes (Chipp, 1970). In general, the veins in the Chandalar area are less than 10 feet thick and are discontinuous, pinching out within a few hundred feet or less. The veins are composed principally of white crystalline to microcrystalline quartz, and their sulfide content is generally less than 5 percent. The principal sulfides (in relative order of abundance) are arsenopyrite, galena, sphalerite, and pyrite. Scorodite and limonite occur commonly as oxidation products. The quartz veins exhibit evidence of shearing, indicating that the veins were emplaced before or during fault movement. Major structural features in the area include large-scale northeast-trending anticlines and synclines, northeast-trending thrusts, and the northwest-trending, high-angle cross faults.? the Summit lode follows the Summit fault and the strikes N80W and dips 75 to 80 degrees south. Early workings on the property exposed a vein 1.5 to 2 feet wide. A sample from these workings was reported to have assayed $54 of gold per ton (Maddren,1913). Dump samples of vein material collected by Chipp (1970) contained abundant arsenopyrite and scorodite in sheared and brecciated quartz; assays of these samples returned values of 0.5 to 6.6 ppm Au. Ashworth (1983) described two generations of quartz at the Summit lode. The older generation is coarsely crystalline, massive, white quartz. It is in the hanging wall and is as much as 4 feet wide. It contains less than 5 percent sulfides and little gold. The younger generation pinches and swells; it adjoins the older veins, but typically follows in the footwall. It is generally finer grained and contains bands accentuated by smeared graphite and arsenopyrite. Scorodite is common, and free gold occurs as blebs and occasional wires. ?The genesis of the gold deposits in the Chandalar district is still in question. 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).

Comment (Deposit): Model Name = Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a)

Comment (Reference): Primary Reference = Chipp, 1970

---

References

Reference (Deposit): Heiner, L.E., and Wolff, E.N., eds., 1968, Mineral resources of northern Alaska, Final report, submitted to the NORTH Commission: Mineral Industry Research Laboratory, University of Alaska, Report 16, 306 p.

Reference (Deposit): Saunders, R.H., 1959, Silver-lead occurrences in the Fairbanks district: Alaska Territorial Department of Mines Miscellaneous Report 194-18, 19 p., 2 maps, scale 1:63,360.

Reference (Deposit): Bundtzen, T.K., Eakins, G.R., and Conwell, C.N., 1982, Review of Alaska mineral resources 1981: Alaska Division of Geological and Geophysical Surveys Annual Report 1981, 48 p.

Reference (Deposit): Cobb, E.H., 1972, Metallic mineral resources map of the Chandalar quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-457, 1 sheet, scale 1:250,000.

Reference (Deposit): Cobb, E.H., 1976, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Chandalar and Wiseman quadrangles, Alaska: U.S. Geological Survey Open-File Report 76-340, 205 p.

Reference (Deposit): Maddren, A.G., 1913, The Koyukuk-Chandalar region, Alaska: U.S. Geological Survey Bulletin 532, 119 p.

Reference (Deposit): Chipp, E.R., 1970, Geology and geochemistry of the Chandalar area, Brooks Range, Alaska: Alaska Division of Geological and Geophysical Surveys Geologic Report 42, 39 p., 1 sheet, scale 1:36,000.

Reference (Deposit): Dillon, J.T., 1982, Source of lode and placer gold deposits of the Chandalar and upper Koyukuk Districts: Alaska Division of Geological and Geophysical Surveys Open-File Report 158, 25 p., 1 sheet, scale 1:250,000.

Reference (Deposit): Ashworth, K.K., 1983, Genesis of gold deposits at the Little Squaw mines, Chandalar mining district, Alaska: Bellingham, Washington, Western Washington University, M.Sc. thesis, 98 p.

Reference (Deposit): Reiser, H.N., Brosgi, W.P., De Young, J.H., Jr., Marsh, S.P., Hamilton, T.D., Cady, J.W., and Albert, N.R.D., 1979, The Alaskan Mineral Resource Assessment Program: Guide to information contained in the folio of geologic and mineral resource maps of the Chandalar quadrangle, Alaska: U.S. Geological Survey Circular 758, 23 p.

Reference (Deposit): Holdsworth, P.R., 1952, Report of the Commissioner of Mines for the Biennium ended December 31, 1952: Alaska Territorial Department of Mines Annual Report 1952, 66 p.

Reference (Deposit): Grybeck, D.J., 1977, Known mineral deposits of the Brooks Range, Alaska: US Geological Survey Open-File Report 77-166C, 41 p., 1 sheet, scale 1:1,000,000.

Reference (Deposit): DeYoung, J.H., Jr., 1978, Mineral resources map of the Chandalar quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-878-B, 2 sheets, scale 1:250,000.

Reference (Deposit): Anderson, Eskil, 1944, Petrographic descriptions of rocks collected during 1944 field investigation in north-west Alaska, and lists of ore and rock samples and placer concentrates collected in northwestern and interior Alaska during 1945 field season: Alaska Territorial Department of Mines Miscellaneous Report 195-28, 76 p.

Reference (Deposit): Boadway, E.A., 1932, Report on Sulzer properties, Chandalar, Alaska: Alaska Territorial Department of Mines Miscellaneous Report 31-6, 23 p., 4 sheets.

Reference (Deposit): Boadway, E.A., 1933, Report on Mikado and Little Squaw veins, Chandalar, Alaska: Alaska Territorial Department of Mines Miscellaneous Report 31-7, 37 p.

Reference (Deposit): Mertie, J.B., Jr., 1925, Geology and gold placers of the Chandalar district, in Brooks, A.H., and others, Mineral resources of Alaska, report on progress of investigations in 1923: U.S. Geological Survey Bulletin 773, p. 215-263.

Reference (Deposit): Cobb, E.H., and Cruz, E.L., 1983, Summaries of data and lists of references to metallic and selected nonmetallic mineral deposits in the Chandalar quadrangle, Alaska: U.S. Geological Survey Open-File Report 83-278, 91 p.

Reference (Deposit): Holdsworth, P.R., 1955, Report of the Commissioner of Mines for the biennium ended December 31, 1954: Alaska Territorial Department of Mines Annual Report 1954, 110 p.

---

The Top Ten Gold Producing States

These ten states contributed the most to the gold production that built the West from 1848 through the 1930s. The Top Ten Gold Producing States.