Year: 2014
Type: dissertation
Abstract: Sandstone-type uranium deposits are among the most economic sources of uranium. Despite their significance, the tabular deposits on the Colorado Plateau and roll-front deposits in Nebraska have not been studied adequately. There are important differences between the tabular Colorado Plateau and Nebraska roll-front deposits, including their ore mineralogy, distribution and habit of ore-bodies, alteration, and mechanisms of ore deposition. The U-Pb ages of uranium minerals from the Colorado deposits indicate four stages of mineralization, spanning from the early Oligocene to late Pliocene. Uranium and V minerals include coffinite, montroseite and carnotite and are associated with both biogenic and non-biogenically precipitated sulphides. Two generations of coffinite mineralization from the Three Crow roll-front deposit in Nebraska were identified. This mineralization precipitated during the early Pliocene and late Miocene. The U-Th activity ratios of U minerals suggest a net accumulation of uranium within the limbs of the roll-front. Evolving oxidation fronts are implied by multiple sulphide generations as indicated by their delta 34S compositions.
Source: Mspace (University of Manitoba)
Author: Angela Meek
Language: English
Subfield: Geochemistry and Petrology
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2794066357