Uranium mining in Arizona
- 1 Carrizo Mountains
- 2 Monument Valley
- 3 Lukachukai Mountains
- 4 Cameron district
- 5 Collapse breccia pipes
- 6 Sierra Ancha district
- 7 Date Creek Basin
- 8 Porphyry copper byproduct
- 9 Uranium mining and the native people
- 10 Current activity
- 11 Pros & Cons of Mining Around the Grand Canyon
- 12 References
- 13 See also
Uranium mining started in 1918 in the Carrizo Mountains as a byproduct of vanadium mining. The district is in Apache County, in the northeast corner of Arizona. The uranium and vanadium occur as carnotite in sandstone of the Salt Wash member of the Morrison Formation (Jurassic). Production stopped in 1921. Another period of mining took place from 1941 to 1966, producing 360,000 pounds (160 metric tons) of uranium oxide (U3O8).
A Navajo discovered uranium in 1942 in Monument Valley on the Navajo Indian Reservation in northeast Arizona. The first mine in the district opened in 1948. Uranium and uranium-vanadium minerals occur in fluvial channels of the Shinarump Sandstone member of the Triassic Chinle Formation. Ore deposits are associated with carbonized wood in the sandstone. Mining stopped in the Monument Valley district in 1969, after producing 8.7 million pounds (3900 metric tons) of uranium oxide, more than has been produced from any other uranium mining district in Arizona. In 2005 the Navajo Nation declared a moratorium on uranium mining on the reservation, for environmental and health reasons.
In 1948, a copper deposit in the Moenkopi Formation was discovered to have economic concentrations of uranium. The deposit was in the Lukachukai Mountains of Apache County. Uranium totaling 3.5 million pounds (1600 metric tons) of U3O8 was produced from 1950 until the mines closed in 1968.
Navajo prospector Hosteen Nez found uranium near Cameron in Coconino County in 1950. The uranium is in the Kayenta Formation and the Chinle Formation. Production was from 1950 to 1963, and totaled 1.2 million pounds (540 metric tons) of U3O8.
Collapse breccia pipes
Uranium was discovered in the Orphan copper mine near the south rim of the Grand Canyon in 1950. The mine has been private property since 1906, and is today completely surrounded by Grand Canyon National Park. The discovery led to the finding of uranium in other collapse breccia pipes in northern Arizona. The breccia pipes were formed when overlying rocks collapsed into caverns formed in the Mississippian Redwall Limestone. The pipes are typically 300 feet (91 m) in diameter, and may extend up to 3,000 feet (910 m) vertically.
Sierra Ancha district
Uranium mining started in 1953 from deposits in the Precambrian Dripping Spring Quartzite in Gila County. The uranium mineral is most commonly uraninite, which occurs with pyrite, marcasite, and chalcopyrite. The orebodies are in veins or strataform deposits within one-half mile of diabase intrusions.
Date Creek Basin
The Anderson uranium deposit was discovered in 1955 by an airborne gamma-radiation survey. Small amounts of ore were produced from 1955 to 1959. Uranium is associated with organic material in carbonaceous Miocene siltstones and mudstones of lacustrine and paludal origin of the Chapin Wash formation of the Date Creek Basin in Yavapai, La Paz, and Mohave counties. The Anderson mine is now owned by Concentric Energy Corp. which is doing extensive development work to bring it into production.
Porphyry copper byproduct
Uranium mining and the native people
After the end of World War II, the United States encouraged uranium mining production because of the nuclear arms race with the U.S.S.R., its opponent in the Cold War. Large uranium deposits were found on and near the Navajo Reservation in the Southwest, and private companies hired many Navajo employees to work the mines. Disregarding the known health risks imposed by exposure to uranium, the private companies and the United States Atomic Energy Commission failed to inform the Navajo workers about the dangers and to regulate the mining to minimize contamination. As more data was collected, they were slow to take appropriate action for the workers.
Studies provided data to show that the Navajo mine workers and numerous families on the reservation have suffered high rates of disease from environmental contamination, but for decades, industry and the government failed to regulate or improve conditions, or inform workers of the dangers. As high rates of illness began to occur, workers were often unsuccessful in court cases seeking compensation, and the states at first did not officially recognize radon illness. In 1990 the US Congress passed the Radiation Exposure Compensation Act, to settle such cases and provide needed compensation.
In 2008 the US Congress authorized a five-year, multi-agency cleanup of uranium contamination on the Navajo Nation reservation; identification and treatment of contaminated water and structures has been the first priority. Certain water sources have been closed, and numerous contaminated buildings have been taken down. By the summer of 2011, EPA had nearly completed the first major project of removal of 20,000 cubic yards of contaminated earth from the Skyline Mine area.
There are currently no producing uranium mines in Arizona. Denison Mines plans to begin mining its Arizona One mine in 2007. The deposit is in a breccia pipe on the Colorado Plateau of northern Arizona. In March 2011, the State of Arizona issued air and water permits to Denison which would allow uranium mining to resume at three locations north of the Grand Canyon, subject to federal approval.
In July 2009 Secretary of the Interior Ken Salazar announced a two-year ban on new mining on federal land in an area of approximately 1 million acres (4,000 km2) surrounding Grand Canyon National Park. Although the ban is on all mining, the main effect is on exploration and development of breccia-pipe uranium deposits. Those claims on which commercial mineral deposits have already been discovered are exempt from the ban. During the two-year ban the Department of the Interior will study a proposed 20-year ban on new mining in the area.
In January 2012, secretary Ken Salazar approved a 20-year ban on mining around the Grand Canyon. This decision preserves about “1 million acres near the Grand Canyon, an area known to be rich in high-grade uranium ore reserves” and has generated a number of different responses 
Pros & Cons of Mining Around the Grand Canyon
Much debate has existed around the risks and benefits of mining around the Grand Canyon and Colorado River. These topics are still widely debated today. The first major controversy discussed is the mining’s effects on the Colorado River and its water. In her article, Suzanne Goldenberg quotes the president of the League of Conservation voters Gene Karpinski: "Extending the current moratorium on new uranium mining claims will protect drinking water for millions downstream.” Many environmental groups agree that the mining would endanger the Colorado River as a source of water for tens of millions of people and countless wildlife. Major cities like Phoenix, Las Vegas and even Los Angeles rely on the river for healthy, drinkable water. With areas of contamination already noted in United States environmental impact reports on old mining operations, opposition fears that allowing mining to expand and continue would only increase the levels of contamination in the river. With this risk in mind, supporters of the mining around the Grand Canyon argue that large-scale contamination from accidents involving mining are unlikely. According to an Arizona Geological survey, “60 metric tons of dissolved uranium is naturally carried by the Colorado River through the Grand Canyon in an average year". J.E. Spencer, AZGS Senior Geologist, argues that in one hypothetical, worst-case scenario experiment, a truck carrying “thirty metric tons (66,000 pounds) of one-percent uranium ore” spilling and washing into the Colorado River increases the natural uranium level in the river by an insignificant amount. Providing further data on uranium levels in the Colorado River, a 2010 United States Geological survey found that the river carries about 40 to 80 tons through the canyon each year.
Opposition to mining around the Grand Canyon also lists tourism-related jobs as a major risk of the mining. The WISE Uranium Project cites The Public News Service as it stated that in 2011 many small businesses across Arizona advocated to Interior Secretary Ken Salazar sign the 20-year ban on new uranium mining near the Grand Canyon in order to preserve thousands of tourism-related jobs. More than 200 small businesses in Arizona addressed postcards to Salazar to support signing the moratorium. President of the League of Conservation voters Gene Karpinski agreed that protecting the tourism industry, which relies on the Grand Canyon, is more important economically than allowing mining companies to act on their claims around the canyon. Opposition to the mining argues that the mining jobs created by allowing mining around the Grand Canyon would not be worth the natural risks such as water contamination. In contrast, support of the mining argues that halting the progress in job creation within the mining industry would be a mistake. Jonathan DuHamel states that a permanent ban on mining would eliminate hundreds of potential jobs. Former presidential candidate John McCain argues that opposition to the mining provoked by environmental groups who have the goal of killing mining and grazing jobs throughout Arizona.
Yet another issue arises as opposition to the mining advocates for the Grand Canyon as an important tourist attraction itself. Many believe that the park is one of the country’s most popular national parks. Coconino County Supervisor Carl Taylor noted that Uranium mining poses a great threat to the safety of this tourism in the canyon and surrounding areas. Many believe that one mining accident could be destructive for tourism in this extremely visited park. Even without accidents, the Environmental Working Group believes that proposed mines in the north of the canyon require helicopter transportation of supplies that intersects with many tourist flyovers that already exist in the area. Interior Secretary Ken Salazar states that “the Grand Canyon attracts more than 4 million visitors a year and generates an estimated $3.5 billion in economic activity”. In his speech to the National Geographic Museum, Salazar also stated that people from the United States and even all over the world come to visit and see the Grand Canyon. He believes that allowing mining in this area to be pursued would negatively impact this tourism industry.
Just as the opposition argues for the protection of tourism, supporters of the mining claim that not allowing it to occur will only drive up uranium prices and hurt both federal and local economies. The increasing number of claims that began in 2006 was a direct result of the rising uranium prices that began that year. The Environmental Working Group cited that “uranium prices have jumped from about $10 a pound in 2004 to approximately $80 a pound today , caused by renewed interest in nuclear power”. With the prices of uranium increasing, it is becoming more profitable for mining companies to locate and mine new deposits like the ones found around the canyon area. Even in 2011, when the price of uranium lowered about 35%, it remained profitable for companies to use these untouched areas. Similarly, many Republicans argue that not allowing the mining to occur destroys years of resource development. Hal Quinn, president and CEO of the National Mining Association states that banning mining in the Grand Canyon only deprives the United States of energy and minerals that are critical to the survival and strength of our economy. The mining industry agrees, believing that a ban on mining around the Grand Canyon would negatively impact Arizona’s local economy and the United States’ energy independence.
- Robert B. Scarborough (1981) Radioactive Occurrences and Uranium Production in Arizona, US Department of Energy, part 3, GJBX-143-(81).
- Roger C. Malan (1968) The uranium mining industry and geology of the Monument Valley and White canyon districts, Arizona and Utah, in Ore Deposits of the United States, 1933-1967, New York: American Institute of Mining Engineers, p.790-804.
- Robert B. Scarorough (1981) Radioactive Occurrences and Uranium Production in Arizona, part 3, US Department of Energy, GJBX-143(81), p.264.
- A.P. Butler Jr. and V.P. Byers (1969) Uranium, in Mineral and Water Resources of Arizona, Arizona Bureau of Mines, Bulletin 180, p.288.
- Andreas Mueller and Peter Halbach, The Anderson mine (Arizona)-an early diagenetic uranium deposit in Miocene lake sediments, Economic Geology, Mar.-Apr. 1983, p.2475-292.
- Concentric Energy Corp. website
- Robert B. Scarborough (1981) Radioactive Occurrences and Uranium Production in Arizona, US Dept. of Energy, GJBX-143(81), p.93.
- Denison Mines, Arizona Strip uranium project, PDF file.
- N. Niemuth, "Arizona," Mining Engineering, May 2007, p.70.
- "Two-year ban on mining near Grand Canyon imposed," Mining Engineering, September 2009, p.7.
- Arizona breccia pipe uranium mineralization
- Uranium mining in the United States
- The Navajo People and Uranium Mining