Grants and world uranium

The Grants uranium region is the premier uranium mining district of the world: the region has yielded the most uranium (113,400 metric tons U3O8), has the highest current rate of production (7,800 metric tons U3O8 in 1978), and has the largest published reserves (430,000 tons U3O8 at a forward cost up to $50 per lb). Most of the ore in Grants is in sandstone, as it is in the other main uranium districts of the United States. The United States deposits of this type have provided a model for exploration around the world. Most of the foreign sandstone deposits illustrate the familiar relationship of uranium ore with plant matter and fluvial channels. Some foregin deposits show the strong influence of structure. Others contain ore in black shaly facies and in aeolian sandstone. Both acid volcanics and granites appear to be likely sources of the uranium