Uranium deposits in the Jackpile Sandstone, New Mexico

Ultimate sources of uranium are believed to be either fluids from Morrison volcanoes (not demonstrable) or labile constituents in the Jackpile Sandstone. Petrographic studies indicate considerable pre-Dakota diagenesis, which would have made uranium in feldspars, heavy minerals, and volcanic debris available. Deposition of uranium occurred while host sandstone was near the surface during the pre-Dakota hiatus. Sedimentary permeability was the principal factor in distribution of ore and of the organic decomposition products that precipitated it.