New Mexico is endowed with the world’s largest known concentration of uranium ore in sandstone. Through 1977 these orebodies yielded 129,150 short tons of U3O8, about 41% of the United States’ supply and 18% of the free world’s supply of yellow cake. Only one foreign nation, Canada, exceeds the state of New Mexico in production. From the 1977 level of about 7,600 tons U3O8, New Mexico’s output is expected to double within the next 10 years, thus maintaining the state’s relative position within the United States. However, the nation’s share of world production is apt to slip as new mines come on-stream in such countries as Australia, Canada, and Niger.
The sandstone uranium deposits of New Mexico, Colorado, Wyoming, and Texas have provided models for exploration around the world, and orebodies of this type are now known in at least 10 countries. Some of the foreign deposits exhibit unusual geologic features or have distinctive exploration histories.
Argentina.—At Sierra Pintada, the largest deposit, the ore is related to pyrite in an eolian sandstone.
Australia.—In the Beverly basin ore was discovered by drilling continental sediments flanking Mt. Painter which contains uranium-bearing veins in granite.
Austria.—At Forstau, pitchblende and coffinite mineralization in Perian sandstone beds was not remobilized during regional metamorphism to the greenischist facies.
Canada.—The Blizzard deposit of British Columbia was found by application of the Tono, Japan, model.
France.—The Herault deposit, in Permian sediments, is controlled partly by faults and partly by lithology.
Gabon.—The deposits are in the oldest host rock (about 2,000 m.y.) known to contain sandstone ore.
Japan.—In the Tono deposit, the ore is contained in paleochannel structures as a uranium-bearing zeolite mineral.
Niger.—The largest resources in sandstone, exclusive of the United States, have been developed in Niger.
South Africa.—The main deposits are in the lower part of the Beaufort Group (of the Karoo Supergroup), but northward the deposits are progressively higher in the section and in younger rocks.