Pentavalent Uranium Incorporated in the Structure of Proterozoic Hematite.
Date
2022
Authors
Ilton, E.S.
Collins, R.N.
Ciobanu, C.L.
Cook, N.J.
Verdugo-Ihl, M.
Slattery, A.D.
Paterson, D.J.
Mergelsberg, S.T.
Bylaska, E.J.
Ehrig, K.
Editors
Advisors
Journal Title
Journal ISSN
Volume Title
Type:
Journal article
Citation
Environmental Science and Technology, 2022; 56(16):11857-11864
Statement of Responsibility
Eugene S. Ilton, Richard N. Collins, Cristiana L. Ciobanu, Nigel J. Cook, Max Verdugo-Ihl, Ashley D. Slattery, David J. Paterson, Sebastian T. Mergelsberg, Eric J. Bylaska, and Kathy Ehrig
Conference Name
Abstract
Characterizing the chemical state and physical disposition of uranium that has persisted over geologic time scales is key for modeling the longterm geologic sequestration of nuclear waste, accurate uranium−lead dating, and the use of uranium isotopes as paleo redox proxies. X-ray absorption spectroscopy coupled with molecular dynamics modeling demonstrated that pentavalent uranium is incorporated in the structure of 1.6 billion year old hematite (α- Fe2O3), attesting to the robustness of Fe oxides as waste forms and revealing the reason for the great success in using hematite for petrogenic dating. The extreme antiquity of this specimen suggests that the pentavalent state of uranium, considered a transient, is stable when incorporated into hematite, a ubiquitous phase that spans the crustal continuum. Thus, it would appear overly simplistic to assume that only the tetravalent and hexavalent states are relevant when interpreting the uranium isotopic record from ancient crust and contained ore systems.
School/Discipline
Dissertation Note
Provenance
Description
Access Status
Rights
© 2022 American Chemical Society