Willow Creek mining district
Encyclopedia
The Willow Creek mining district, also known as the Independence Mine/Hatcher Pass
district, is a gold-mining
area in the U.S. state of Alaska
. Underground hard-rock mining of gold from quartz veins accounts for most of the mineral wealth extracted from the Hatcher Pass area. The first mining efforts were placer mining of stream gravels, and placer mining in the area has continued sporadically to this day. Robert Hatcher discovered gold and staked the first claim in the Willow Creek valley in September 1906. The first lode mill in the area started operating in 1908. Underground mining continued at a variety of locations around the pass until 1951. In the 1980s one of the area's hard-rock mines was briefly re-opened. At least one mining company is actively exploring for gold in the area now.
Through 2006 the district produced 667-thousand ounces of hard rock gold and 60-thousand ounces of placer gold.
The lode gold mines at Hatcher Pass exploit gold-bearing quartz (+/- Ag, W, Sb, As, Cu, Mo, Pb, Te, Zn, Hg) veins in a variety of granitic intrusive rocks and country-rock schist. Near the pass, the southwestern margin of the Tertiary-Cretaceous-age Talkeetna Mountains batholith abuts an older pelitic schist unit. The Talkeetna Mountains batholith in this area consists of a 74ma-old tonalite body to the east and a 67ma-old quartz monzonite to the west. The schist consists mainly of metamorphosed and deformed sedimentary rocks, probably of Jurassic age. Plutonic bodies and dikes of Jurassic age are found within the schist, some are deformed, some postdate deformation. Undeformed Tertiary terrastial sediments of the Chickaloon and Arkose Ridge Formations lie to the south of the Jurassic schists and intrusives.
Gold deposits occur in the 74ma-old tonalite, the enclosing schist, and the Jurassic intrusives, but not in the 67ma-old quartz monzonite or in the Tertiary sediments.
What is now called Independence Mine was once two mines: The Alaska Free Gold Mine on Skyscraper Mountain, and Independence Mine on Granite Mountain. In 1938 the two were brought together under one company, the Alaska-Pacific Consolidated Mining Company (APC). With a block of 83 mining claims, APC became the largest producer in the Willow Creek Mining District. The claims covered more than 1350 acres (5.5 km²) and included 27 structures. In its peak year, 1941, APC employed 204 men, blasted nearly a dozen miles of tunnels, and produced about 35,000 ounces of gold.
In 1942, the War Production Board designated gold mining as nonessential to the war effort. Gold mining throughout the United States came to a halt, but Independence Mine was permitted to continue to operate because of the presence of scheelite
, an ore of the "strategic mineral" tungsten
, which occurs in the quartz lode
with the gold. In 1943, Independence Mine was ordered to close. Mining interests returned to Hatchers Pass when gold prices rose in the mid-1970s; this resulted in a short period of production from the Independence Mine in 1982 by Coronado Mining Company.
Today, Independence Mine is a part of the Independence Mine State Historical Park, a popular winter recreation area. Displays of mining artifacts may also be viewed at the Dorothy Page Museum and Old Wasilla Townsite in downtown Wasilla, Alaska
.
The Independence was the largest mine in the Willow Creek District, over a dozen other hard rock mines operated, and may operate again, within a few miles.
The Willow Creek Mines includes the Lucky Shot mine (Gold, copper, lead, zinc, arsenic) and War Baby mine (Gold, copper) veins, which produced from veins cutting the igneous country rock. Combined production for the two mines between 1919 and 1940 was about 252,000 ounces of gold, with some copper. Grade was about 2.2 ounces of gold per ton.
The Fern Mine (Gold, lead, tungsten, tellurium), produced about 44,000 ounces of gold between 1922 and 1950 from quartz veins in shears in igneous rock.
The Martin Mine (Gold, copper, lead), produced about 28,000 ounces of gold from two veins between 1911 and 1920, at an average grade of 1 ounce per ton.
The Gold Cord Mine (Gold, copper, lead, zinc, tungsten), produced about 16,000 ounces of gold, mainly between 1931 and 1938, from veins with grades ranging for 0.1 to 9 ounces per ton.
Hatcher Pass
Hatcher Pass is a mountain pass through the southwest part of the Talkeetna Mountains, Alaska. It is named after Robert Hatcher, a prospector and miner. The nearest incorporated communities are Palmer and Wasilla, approximately to the south, and Willow, approximately to the west...
district, is a gold-mining
Gold mining
Gold mining is the removal of gold from the ground. There are several techniques and processes by which gold may be extracted from the earth.-History:...
area in the U.S. state of Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
. Underground hard-rock mining of gold from quartz veins accounts for most of the mineral wealth extracted from the Hatcher Pass area. The first mining efforts were placer mining of stream gravels, and placer mining in the area has continued sporadically to this day. Robert Hatcher discovered gold and staked the first claim in the Willow Creek valley in September 1906. The first lode mill in the area started operating in 1908. Underground mining continued at a variety of locations around the pass until 1951. In the 1980s one of the area's hard-rock mines was briefly re-opened. At least one mining company is actively exploring for gold in the area now.
Through 2006 the district produced 667-thousand ounces of hard rock gold and 60-thousand ounces of placer gold.
The lode gold mines at Hatcher Pass exploit gold-bearing quartz (+/- Ag, W, Sb, As, Cu, Mo, Pb, Te, Zn, Hg) veins in a variety of granitic intrusive rocks and country-rock schist. Near the pass, the southwestern margin of the Tertiary-Cretaceous-age Talkeetna Mountains batholith abuts an older pelitic schist unit. The Talkeetna Mountains batholith in this area consists of a 74ma-old tonalite body to the east and a 67ma-old quartz monzonite to the west. The schist consists mainly of metamorphosed and deformed sedimentary rocks, probably of Jurassic age. Plutonic bodies and dikes of Jurassic age are found within the schist, some are deformed, some postdate deformation. Undeformed Tertiary terrastial sediments of the Chickaloon and Arkose Ridge Formations lie to the south of the Jurassic schists and intrusives.
Gold deposits occur in the 74ma-old tonalite, the enclosing schist, and the Jurassic intrusives, but not in the 67ma-old quartz monzonite or in the Tertiary sediments.
Independence mine
In 1942, the War Production Board designated gold mining as nonessential to the war effort. Gold mining throughout the United States came to a halt, but Independence Mine was permitted to continue to operate because of the presence of scheelite
Scheelite
Scheelite is a calcium tungstate mineral with the chemical formula CaWO4. It is an important ore of tungsten. Well-formed crystals are sought by collectors and are occasionally fashioned into gemstones when suitably free of flaws...
, an ore of the "strategic mineral" tungsten
Tungsten
Tungsten , also known as wolfram , is a chemical element with the chemical symbol W and atomic number 74.A hard, rare metal under standard conditions when uncombined, tungsten is found naturally on Earth only in chemical compounds. It was identified as a new element in 1781, and first isolated as...
, which occurs in the quartz lode
Lode
In geology, a lode is a deposit of metalliferous ore that fills or is embedded in a fissure in a rock formation or a vein of ore that is deposited or embedded between layers of rock....
with the gold. In 1943, Independence Mine was ordered to close. Mining interests returned to Hatchers Pass when gold prices rose in the mid-1970s; this resulted in a short period of production from the Independence Mine in 1982 by Coronado Mining Company.
Today, Independence Mine is a part of the Independence Mine State Historical Park, a popular winter recreation area. Displays of mining artifacts may also be viewed at the Dorothy Page Museum and Old Wasilla Townsite in downtown Wasilla, Alaska
Wasilla, Alaska
Wasilla is a city in Matanuska-Susitna Borough, United States and the sixth-largest city in Alaska. It is located on the northern point of Cook Inlet in the Matanuska-Susitna Valley of the southcentral part of the state. The city's population was 7,831 at the 2010 census...
.
The Independence was the largest mine in the Willow Creek District, over a dozen other hard rock mines operated, and may operate again, within a few miles.
Willow Creek mines
Other Notable Lode-Gold mines of the District
The Gold Bullion Mine (Gold, copper, mercury), produced about 77,000 ounces of gold, at a grade of 1.7 ounces per ton, from quartz veins in igneous rock.The Fern Mine (Gold, lead, tungsten, tellurium), produced about 44,000 ounces of gold between 1922 and 1950 from quartz veins in shears in igneous rock.
The Martin Mine (Gold, copper, lead), produced about 28,000 ounces of gold from two veins between 1911 and 1920, at an average grade of 1 ounce per ton.
The Gold Cord Mine (Gold, copper, lead, zinc, tungsten), produced about 16,000 ounces of gold, mainly between 1931 and 1938, from veins with grades ranging for 0.1 to 9 ounces per ton.