Juneau mining district
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Juneau mining district | |
— Alaska Mining District — | |
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The Juneau mining district is a gold mining area in the U.S. state of Alaska.
In 1880 a local inhabitant, Chief Kowee, revealed to prospectors Joe Juneau and Richard Harris the presence of gold in what is now named Gold Creek in Silver Bow Basin. The city of Juneau was founded there that year.
The strike sparked the Juneau gold rush which resulted in the development of many placer and lode mines including the largest, in their time, gold mines in the world: the Treadwell complex of lode mines on Douglas Island (across a narrow sea channel from Juneau) and the AJ lode mine, in Juneau itself. The steep, wet, timber-covered, seaside mountain setting provided water power, transportation, and lumber such that, "extraordinarily low costs of operation make available low grade ore that under conditions only slightly different would be valueless."[1]
The first claims of what was to become the Treadwell complex were staked in 1881. Mining the Treadwell site began by sluicing residual placers over the lode deposits. Underground mining began with a five-stamp mill operating in 1883. In the mid-1910's, with 960 stamps grinding ore and tunnels reaching as far as 2400 feet below the surface and extending under the sea, Treadwell was one of the most technologically advanced mines of its day. Up to 2000 people worked at the mine before a collapse allowed the rising tide to flood the tunnels in 1917. All operations at the Treadwell ceased by 1922. [2]
As the Treadwell mines declined and closed, the AJ mine rose in prominence. After years of losses and labor problems, the mine became profitable in the mid-1920's: with 600 workers it was setting production records. Through the decade, it was the main economic engine of Juneau. In the 1930's, with 1000 workers, it was an important factor in softening the impact upon Juneau of the Great Depression. [3]
Economic pressures of WWII lead to the closure of the AJ in 1944; this was the end of the dominance of mining in the Juneau economy. [4]
Although those two mines are long-since closed, as late as 1980 one of the hydropower plants built to power the AJ was still in use. [5] Fires and time have destroyed most traces of the Treadwell complex; the AJ mine buildings still tower over the Gastineau Channel south of Juneau.
The Juneau mining district; comprising the area between the Canadian border, Lynn Canal, Admiralty Island, and Frederick Sound, has produced over 7 million ounces of lode gold and 80,000 ounces of placer gold.[6]
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[edit] Treadwell mine
See main article Treadwell gold mine.
French Canadian prospector Pierre Erussard, known as “French Pete,” found gold on Douglas Island, across Gastineau Channel from Juneau. A consortium led by John Treadwell, a carpenter from California, purchased the claims and adjoining gold-bearing land. The resulting mine/mill complex produced more than 3 million troy ounces (93 tonnes) of gold before closing in 1922.
[edit] Kensington & Jualin mines (under development)
The underground Kensington hardrock mine is approximately 45 miles north of Juneau. The mine site is within the City and Borough of Juneau and the Tongass National Forest.
Development and ore production occurred at the Kensington mine site from 1897 through 1938. The adjacent, also underground, Jualin mine was discovered in 1895 and operated from 1896 to 1928. Together the mines produced 40,513 ounces of gold from 75,208 tons of ore.
Interest in the dormant mines was renewed during the 1980s and 1990s. The Kensington Project is now in the final stages of permitting. The proposed underground mine will produce approximately 2,000 tons of ore per day and 400 tons per day of development rock over an estimated 10 years. The project now encompasses both the Kensington and Jualin prospects. The proposed mine, access roads, and tailings disposal areas are located on federal land overseen by the U.S. Forest Service (USFS), State of Alaska tidelands, and on private patented property.[7] The project will employ approximately 300 to 400 people during the 22 months required for construction of the facilities and 225 full time employees to operate the mine and processing facilities.
[edit] See also
[edit] References
- ^ Eakin, H.M., p96., Mineral Resources of Alaska, 1914, USGS Bulletin 622
- ^ David Stone and Brenda Stone (1987) Hard Rock Gold, Vanguard Press.
- ^ http://juneaualaska.com/history/history_1920mudslide.shtml
- ^ Juneau Empire: History of Juneau
- ^ http://www.sia-web.org/sian/images/sianv7/sianv74pg1.pdf
- ^ Alaskas Mineral Industry 2006, Alaska DGGS Special Report 61, 2006
- ^ http://www.dnr.state.ak.us/mlw/mining/largemine/kensington/index.htm Alaska DNR: Kensington Mine Project