Abstract

A vanadium-uranium deposit on East Rifle Creek, Colorado is one of the largest of its kind on the Colorado Plateau. The deposit was developed by the Rifle and Garfield Mines. From 1925 through 1977 the mines produced about 47 million pounds of vanadium oxide (V₂O₅). About 1 million pounds of uranium oxide (U₃O₈) were recovered as a byproduct.

The host rocks for the deposit are the Triassic Chinle Formation, Triassic-Jurassic Glen Canyon Sandstone, and the Jurassic Entrada Sandstone. Most of the ore has been produced from the Glen Canyon Sandstone. The primary vanadium minerals of the deposit consist dominantly of micaceous silicates with a small amount of montroseite, an oxide. The only uranium minerals recognized are secondary.

A zoning of uranium, vanadium, and selenium in the deposit is believed to be due to precipitation at an interface between a carbonate solution and a sulfate solution.