Paleodepositional conditions in the Orca Basin as inferred from organic matter and trace metal contents
International audience Keywords: Gulf of Mexico Holocene anoxia euxinia geochemistry molybdenum nickel chromium brines The Orca Basin, located in the Gulf of Mexico, is a highly stratified basin that collects sedimentary particles of clastic origin (supplied by the Mississippi River) and of biogenic...
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Online Access: | https://hal.science/hal-00683633 https://doi.org/10.1016/j.margeo.2008.04.016 |
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ftsorbonneuniv:oai:HAL:hal-00683633v1 2023-06-11T04:15:47+02:00 Paleodepositional conditions in the Orca Basin as inferred from organic matter and trace metal contents Tribovillard, Nicolas Bout-Roumazeilles, Viviane Algeo, Thomas Lyons, Timothy W. Sionneau, Thomas Montero-Serrano, Jean Carlos Riboulleau, Armelle Baudin, François Bout‑roumazeilles, Viviane Lyons, Timothy, Montero-Serrano, Jean Géosystèmes - UMR 8157 Université de Lille, Sciences et Technologies-Centre National de la Recherche Scientifique (CNRS) Department of Geology University of Cincinnati (UC) Department of Earth Sciences Riverside University of California Riverside (UC Riverside) University of California (UC)-University of California (UC) Institut des Sciences de la Terre de Paris (iSTeP) Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS) 2008 https://hal.science/hal-00683633 https://doi.org/10.1016/j.margeo.2008.04.016 en eng HAL CCSD Elsevier info:eu-repo/semantics/altIdentifier/doi/10.1016/j.margeo.2008.04.016 hal-00683633 https://hal.science/hal-00683633 doi:10.1016/j.margeo.2008.04.016 ISSN: 0025-3227 Marine Geology https://hal.science/hal-00683633 Marine Geology, 2008, 254 (1-2), pp.62-72. ⟨10.1016/j.margeo.2008.04.016⟩ [SDU.STU]Sciences of the Universe [physics]/Earth Sciences info:eu-repo/semantics/article Journal articles 2008 ftsorbonneuniv https://doi.org/10.1016/j.margeo.2008.04.016 2023-05-29T16:26:29Z International audience Keywords: Gulf of Mexico Holocene anoxia euxinia geochemistry molybdenum nickel chromium brines The Orca Basin, located in the Gulf of Mexico, is a highly stratified basin that collects sedimentary particles of clastic origin (supplied by the Mississippi River) and of biogenic origin (marine surface productivity). The strong pycnocline induces anoxic bottom conditions that are expected to be favorable to organic matter (OM) accumulation and prone to enrichment of sediments in redox-sensitive trace metals. Here we report on OM and trace metal contents in the upper 750 cm below sea floor (cmbsf) of Core MD02-2552 (mostly Holocene) and deposited under permanently stratified bottom conditions. The organic content is dominated by marine-derived amorphous OM. Contrary to expectations, sedimentary OM in the basin is highly degraded, probably due to a long residence time of organic particles at the basin's basin's halocline at~2240 m. Also unexpected is the limited sedimentary enrichment of redox-sensitive trace metals. We suggest that the non-enrichment in U and V could be explained by the so-called basin reservoir effect, that is, limited metal availability because of low rates of water renewal in a strongly restricted subpycnoclinal water mass. The non-enrichment in Cu could have the same cause, plus the fact that the relatively degraded OM may not readily form organometallic complexes. However a marked enrichment is observed for Mo, and a moderate one for Ni and Cr, which could be accounted for by sporadic presence of H 2 S in bottom waters. Such occurrences of H 2 S would not be sufficient to promote a detectable FeS to FeS 2 conversion, but they would induce the capture of Mo in the form of thiomolybdate and accessorily Ni-Cr as Ni-CrO 4 complexes. Article in Journal/Newspaper Orca HAL Sorbonne Université Marine Geology 254 1-2 62 72 |
institution |
Open Polar |
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HAL Sorbonne Université |
op_collection_id |
ftsorbonneuniv |
language |
English |
topic |
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
spellingShingle |
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences Tribovillard, Nicolas Bout-Roumazeilles, Viviane Algeo, Thomas Lyons, Timothy W. Sionneau, Thomas Montero-Serrano, Jean Carlos Riboulleau, Armelle Baudin, François Bout‑roumazeilles, Viviane Lyons, Timothy, Montero-Serrano, Jean Paleodepositional conditions in the Orca Basin as inferred from organic matter and trace metal contents |
topic_facet |
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
International audience Keywords: Gulf of Mexico Holocene anoxia euxinia geochemistry molybdenum nickel chromium brines The Orca Basin, located in the Gulf of Mexico, is a highly stratified basin that collects sedimentary particles of clastic origin (supplied by the Mississippi River) and of biogenic origin (marine surface productivity). The strong pycnocline induces anoxic bottom conditions that are expected to be favorable to organic matter (OM) accumulation and prone to enrichment of sediments in redox-sensitive trace metals. Here we report on OM and trace metal contents in the upper 750 cm below sea floor (cmbsf) of Core MD02-2552 (mostly Holocene) and deposited under permanently stratified bottom conditions. The organic content is dominated by marine-derived amorphous OM. Contrary to expectations, sedimentary OM in the basin is highly degraded, probably due to a long residence time of organic particles at the basin's basin's halocline at~2240 m. Also unexpected is the limited sedimentary enrichment of redox-sensitive trace metals. We suggest that the non-enrichment in U and V could be explained by the so-called basin reservoir effect, that is, limited metal availability because of low rates of water renewal in a strongly restricted subpycnoclinal water mass. The non-enrichment in Cu could have the same cause, plus the fact that the relatively degraded OM may not readily form organometallic complexes. However a marked enrichment is observed for Mo, and a moderate one for Ni and Cr, which could be accounted for by sporadic presence of H 2 S in bottom waters. Such occurrences of H 2 S would not be sufficient to promote a detectable FeS to FeS 2 conversion, but they would induce the capture of Mo in the form of thiomolybdate and accessorily Ni-Cr as Ni-CrO 4 complexes. |
author2 |
Géosystèmes - UMR 8157 Université de Lille, Sciences et Technologies-Centre National de la Recherche Scientifique (CNRS) Department of Geology University of Cincinnati (UC) Department of Earth Sciences Riverside University of California Riverside (UC Riverside) University of California (UC)-University of California (UC) Institut des Sciences de la Terre de Paris (iSTeP) Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Tribovillard, Nicolas Bout-Roumazeilles, Viviane Algeo, Thomas Lyons, Timothy W. Sionneau, Thomas Montero-Serrano, Jean Carlos Riboulleau, Armelle Baudin, François Bout‑roumazeilles, Viviane Lyons, Timothy, Montero-Serrano, Jean |
author_facet |
Tribovillard, Nicolas Bout-Roumazeilles, Viviane Algeo, Thomas Lyons, Timothy W. Sionneau, Thomas Montero-Serrano, Jean Carlos Riboulleau, Armelle Baudin, François Bout‑roumazeilles, Viviane Lyons, Timothy, Montero-Serrano, Jean |
author_sort |
Tribovillard, Nicolas |
title |
Paleodepositional conditions in the Orca Basin as inferred from organic matter and trace metal contents |
title_short |
Paleodepositional conditions in the Orca Basin as inferred from organic matter and trace metal contents |
title_full |
Paleodepositional conditions in the Orca Basin as inferred from organic matter and trace metal contents |
title_fullStr |
Paleodepositional conditions in the Orca Basin as inferred from organic matter and trace metal contents |
title_full_unstemmed |
Paleodepositional conditions in the Orca Basin as inferred from organic matter and trace metal contents |
title_sort |
paleodepositional conditions in the orca basin as inferred from organic matter and trace metal contents |
publisher |
HAL CCSD |
publishDate |
2008 |
url |
https://hal.science/hal-00683633 https://doi.org/10.1016/j.margeo.2008.04.016 |
genre |
Orca |
genre_facet |
Orca |
op_source |
ISSN: 0025-3227 Marine Geology https://hal.science/hal-00683633 Marine Geology, 2008, 254 (1-2), pp.62-72. ⟨10.1016/j.margeo.2008.04.016⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.margeo.2008.04.016 hal-00683633 https://hal.science/hal-00683633 doi:10.1016/j.margeo.2008.04.016 |
op_doi |
https://doi.org/10.1016/j.margeo.2008.04.016 |
container_title |
Marine Geology |
container_volume |
254 |
container_issue |
1-2 |
container_start_page |
62 |
op_container_end_page |
72 |
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1768372896967688192 |