The behavior of U in near surface sedimentary environments has changed throughout geologic time. There is a marked shift in U (IV) mineral stability and deposit style at approximately 2200 Ma due to changes in the concentration of O in the atmosphere. For example, prior to 2200 Ma, fluvial U deposits could form and U(IV) were stable in surface and near-surface environments. In modern, anthropogenic sedimentary systems such as U tailings, U (IV) minerals are not stable and readily oxidize to U (VI) minerals. In addition, U is much more mobile in modern sediments relative sediments that were deposited prior to 2200 Ma.
| Identifer | oai:union.ndltd.org:MANITOBA/oai:mspace.lib.umanitoba.ca:1993/14431 |
| Date | January 2012 |
| Creators | Bergen, Laura |
| Contributors | Fayek, Mostafa (Geological Sciences), Sherriff, Barbara (Geological Sciences) Schreckenbach, Georg (Chemistry) |
| Publisher | American Mineralogist |
| Source Sets | University of Manitoba Canada |
| Detected Language | English |
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