Influence of Sediment Cycling on the Rare-Earth Element Geochemistry of Fluvial Deposits (Caculuvar–Mucope, Cunene River Basin, Angola)
The rare-earth element (REE) geochemistry of sedimentary deposits has been used in provenance investigations despite the transformation that this group of elements may suffer during a depositional cycle. In the present investigation, we used the geochemistry and XRD mineralogy of a set of sand and m...
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MDPI AG
2021-09-01
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| Online Access: | https://www.mdpi.com/2076-3263/11/9/384 |
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| author | Armanda Cruz Pedro A. Dinis Alberto Gomes Paula Leite |
| author_facet | Armanda Cruz Pedro A. Dinis Alberto Gomes Paula Leite |
| author_sort | Armanda Cruz |
| collection | DOAJ |
| description | The rare-earth element (REE) geochemistry of sedimentary deposits has been used in provenance investigations despite the transformation that this group of elements may suffer during a depositional cycle. In the present investigation, we used the geochemistry and XRD mineralogy of a set of sand and mud fluvial deposits to evaluate the ability of REE parameters in provenance tracing, and the changes in REE geochemistry associated with weathering and sorting. The analyzed deposits were generated in a subtropical drainage basin where mafic and felsic units are evenly represented, and these crystalline rocks are covered by sedimentary successions in a wide portion of the basin. A few element ratios appear to hold robust information about primary sources (Eu/Y, Eu/Eu*, La<sub>N</sub>/Yb<sub>N</sub>, La<sub>N</sub>/Sm<sub>N</sub>, and Gd<sub>N</sub>/Yb<sub>N</sub>), and the provenance signal is best preserved in sand than in mud deposits. Sediment cycles, however, change the REE geochemistry, affecting mud and sand deposits differently. They are responsible for significant REE depletion through quartz dilution in sands and may promote discernible changes in REE patterns in muds (e.g., increase in Ce content and some light REE depletion relative to heavy REE). |
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| issn | 2076-3263 |
| language | English |
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| spelling | doaj.art-21e4ab357a9f44c78ae0137c2acaa3e02023-11-22T13:16:08ZengMDPI AGGeosciences2076-32632021-09-0111938410.3390/geosciences11090384Influence of Sediment Cycling on the Rare-Earth Element Geochemistry of Fluvial Deposits (Caculuvar–Mucope, Cunene River Basin, Angola)Armanda Cruz0Pedro A. Dinis1Alberto Gomes2Paula Leite3MARE-Marine and Environmental Sciences Centre, Departament of Earth Sciences, University of Coimbra, 3030-790 Coimbra, PortugalMARE-Marine and Environmental Sciences Centre, Departament of Earth Sciences, University of Coimbra, 3030-790 Coimbra, PortugalCEGOT—Centre of Studies in Geography and Spatial Planning, Department of Geography, University of Porto, 4150-564 Porto, PortugalCEGOT—Centre of Studies in Geography and Spatial Planning, Department of Geography, University of Porto, 4150-564 Porto, PortugalThe rare-earth element (REE) geochemistry of sedimentary deposits has been used in provenance investigations despite the transformation that this group of elements may suffer during a depositional cycle. In the present investigation, we used the geochemistry and XRD mineralogy of a set of sand and mud fluvial deposits to evaluate the ability of REE parameters in provenance tracing, and the changes in REE geochemistry associated with weathering and sorting. The analyzed deposits were generated in a subtropical drainage basin where mafic and felsic units are evenly represented, and these crystalline rocks are covered by sedimentary successions in a wide portion of the basin. A few element ratios appear to hold robust information about primary sources (Eu/Y, Eu/Eu*, La<sub>N</sub>/Yb<sub>N</sub>, La<sub>N</sub>/Sm<sub>N</sub>, and Gd<sub>N</sub>/Yb<sub>N</sub>), and the provenance signal is best preserved in sand than in mud deposits. Sediment cycles, however, change the REE geochemistry, affecting mud and sand deposits differently. They are responsible for significant REE depletion through quartz dilution in sands and may promote discernible changes in REE patterns in muds (e.g., increase in Ce content and some light REE depletion relative to heavy REE).https://www.mdpi.com/2076-3263/11/9/384rare-earth elementsfluvial sedimentsrecognition of primary sourcesexogenous compositional transformationsCunene River Basin |
| spellingShingle | Armanda Cruz Pedro A. Dinis Alberto Gomes Paula Leite Influence of Sediment Cycling on the Rare-Earth Element Geochemistry of Fluvial Deposits (Caculuvar–Mucope, Cunene River Basin, Angola) Geosciences rare-earth elements fluvial sediments recognition of primary sources exogenous compositional transformations Cunene River Basin |
| title | Influence of Sediment Cycling on the Rare-Earth Element Geochemistry of Fluvial Deposits (Caculuvar–Mucope, Cunene River Basin, Angola) |
| title_full | Influence of Sediment Cycling on the Rare-Earth Element Geochemistry of Fluvial Deposits (Caculuvar–Mucope, Cunene River Basin, Angola) |
| title_fullStr | Influence of Sediment Cycling on the Rare-Earth Element Geochemistry of Fluvial Deposits (Caculuvar–Mucope, Cunene River Basin, Angola) |
| title_full_unstemmed | Influence of Sediment Cycling on the Rare-Earth Element Geochemistry of Fluvial Deposits (Caculuvar–Mucope, Cunene River Basin, Angola) |
| title_short | Influence of Sediment Cycling on the Rare-Earth Element Geochemistry of Fluvial Deposits (Caculuvar–Mucope, Cunene River Basin, Angola) |
| title_sort | influence of sediment cycling on the rare earth element geochemistry of fluvial deposits caculuvar mucope cunene river basin angola |
| topic | rare-earth elements fluvial sediments recognition of primary sources exogenous compositional transformations Cunene River Basin |
| url | https://www.mdpi.com/2076-3263/11/9/384 |
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