This title appears in the Scientific Report :
2020
Please use the identifier:
http://hdl.handle.net/2128/25751 in citations.
Please use the identifier: http://dx.doi.org/10.1016/j.apgeochem.2019.104476 in citations.
‘Co-evolution’ of uranium concentration and oxygen stable isotope in phosphate rocks
‘Co-evolution’ of uranium concentration and oxygen stable isotope in phosphate rocks
Phosphate rocks (PRs) used in fertilizer production contain uranium (U), which enters agricultural soils through phosphorus fertilization. However, our knowledge is still limited and cannot explain the different levels of U contamination found in agricultural systems. The paper reviewed the spatial...
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Personal Name(s): | Sun, Y. (Corresponding author) |
---|---|
Amelung, W. / Wu, Bei / Haneklaus, S. / Maekawa, M. / Lücke, A. / Schnug, E. / Bol, R. | |
Contributing Institute: |
Agrosphäre; IBG-3 |
Published in: | Applied geochemistry, 114 (2020) S. 104476 - |
Imprint: |
Amsterdam [u.a.]
Elsevier Science
2020
|
DOI: |
10.1016/j.apgeochem.2019.104476 |
Document Type: |
Journal Article |
Research Program: |
Terrestrial Systems: From Observation to Prediction |
Link: |
Published on 2019-11-20. Available in OpenAccess from 2021-11-20. Published on 2019-11-20. Available in OpenAccess from 2021-11-20. |
Publikationsportal JuSER |
Please use the identifier: http://dx.doi.org/10.1016/j.apgeochem.2019.104476 in citations.
Phosphate rocks (PRs) used in fertilizer production contain uranium (U), which enters agricultural soils through phosphorus fertilization. However, our knowledge is still limited and cannot explain the different levels of U contamination found in agricultural systems. The paper reviewed the spatial and temporal U variations in PRs to obtain a comprehensive overview of U levels in various PRs worldwide and to investigate why U concentrations in igneous PRs are significantly lower compared to sedimentary PRs, and why less U is present in old sedimentary PRs (Precambrian-Cambrian) than in younger PRs (Ordovician-Neogene). In addition, the natural oxygen isotope compositions of phosphate (δ18Op) in various PRs were determined to identify their origins in relation to their U concentration. The δ18Op values differed among igneous PRs, old sedimentary PRs, and younger sedimentary PRs. Generally, the PRs with low δ18Op values had low U concentrations. In igneous PRs, low U concentrations were due to the lack of secondary U enrichment processes after rock formation, with low δ18Op values resulting from limited isotope fractionation at high temperature. Conversely, in sedimentary PRs, both U concentrations and δ18Op values were influenced by paleoclimate and paleogeographic features. Overall, there is a time-dependent coincidence of processes altering U concentration and δ18Op signatures of sedimentary PRs in a similar direction. |