Big Creek Mine, Chandalar Mining District, Yukon-Koyukuk Census Area, Alaska, USAi

Regional Level Types
Big Creek Mine	Mine
Chandalar Mining District	Mining District
Yukon-Koyukuk Census Area	Census Area
Alaska	State
USA	Country

See also: St. Marys Gulch (Creek) (CH044). The first recorded occurrence of monazite in Alaska was from Big Creek (Mertie, 1925, p. 260).
Location: This gold placer is approximately 5 1/2 miles south of the south end of Squaw Lake. The coordinates are at the mine symbol shown on the topographic map; this is the last camp that was used for placer mining on Big Creek. It is near the junction of sections 9, 10, 15, and 16, T. 31 N., R. 3 W., of the Fairbanks Meridian. Chipp (1970) showed that the stream has been placer mined at least a mile upstream from the camp and about 1/4 miles below it. The location is accurate.
Geology: Big Creek is one of the major placer gold producers in the Chandalar district. The placers along the creek were worked only by small-scale methods until the 1950s, when bulldozers were brought in. In the early days, some drift mining was done in the frozen gravel. Mining continued sporadically through at least the mid-1990s. In 2004, Little Squaw Gold Mining Company controlled 8,550 acres of patented and unpatented mining claims in the Chandalar district which includes all or part of the auriferous portion of Big Creek. 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). Big Creek drains the area where several of the Chandalar gold quartz properties are located (CH040-042). The gravels in the stream are relatively shallow, averaging about 12 feet deep on the uppermost portion of the creek and deepening to about 20 to 22 feet on the lower portion of the mined ground (Reed, 1930A, Reed 1930B). The gold occurs in the lower 3 to 5 feet, and there is very little gold on bedrock. The gravel is fairly coarse with numerous greenstone boulders as much as 3 feet in diameter. There is only one generation of placers in the drainage. (They are not separable into pre- and post-glacial deposits). The gold is reported to be bright yellow, generally irregular, and shot-like to flattened, but some occurs as crystals. The gold averages 1 millimeter with many 2- to 3-millimeter nuggets. A few nuggets contain included quartz crystals, limonite, and goethite. It is also reported that the concentrates contain a large suite of heavy minerals in addition to the gold (Mertie, 1925; White, 1952). These heavy minerals include monazite, magnetite, hematite, rutile, pyrite, arsenopyrite, chalcopyrite, galena, stibnite, molybdenite, scheelite, and uranothorianite. A panned-concentrate sample had eU of 0.05 percent (White, 1952, p. 11). Coarse gold was reported several miles downstream from the mined area, but there is no evidence that mining has occurred in this lower area. There are at least two reports of a quartz vein in the creek bed on the upper reaches of Big Creek (Chipp, 1970; Heiner and Wolff, 1968). Heiner and Wolff (1968) described it as a gold-bearing mineralized zone that may extend from Big Creek to upper Tobin Creek.
Workings: The placers along Big Creek were worked only by small-scale methods until the 1950s, when bulldozers were brought in. Some drift mining was done in the frozen gravel. Mining continued sporadically through at least the mid-1990s. In 2004, Little Squaw Gold Mining Company controlled 8,550 acres of patented and unpatented mining claims in the Chandalar district which includes all or part of the auriferous portion of Big Creek. 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: Quaternary.
Production: Big Creek has been a major producer in the Chandalar district. Chipp (1970) reported production from Big Creek to be about 15,000 ounces of gold and Dillon (1982) stated that two-thirds of that total was produced after 1950. There are no reliable figures for later years.

Commodities (Major) - Au; (Minor) - Ag, As, Cu, Mo, Pb, REE, Sb, Th, Ti, U, W
Development Status: Yes; medium
Deposit Model: Placer Au (Cox and Singer, 1986; model 39a)

Other Databases

Link to USGS - Alaska:	CH043

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References