Does a strong pycnocline impact organic-matter preservation and accumulation in an anoxic setting? The case of the Orca Basin, Gulf of Mexico

• Published in: Comptes Rendus Geoscience
• Main Authors: Tribovillard, Nicolas, Bout‑Roumazeilles, Viviane, Sionneau, Thomas, Serrano, Montero, Riboulleau, Armelle, Baudin, François
• Other Authors: Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 (LOG), Centre National de la Recherche Scientifique (CNRS)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Institut national des sciences de l'Univers (INSU - CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2009
• Subjects: [SDE]Environmental Sciences; [SDU]Sciences of the Universe [physics]; [SDV]Life Sciences [q-bio]; [PHYS]Physics [physics]; Orca
• Online Access: https://hal.archives-ouvertes.fr/hal-03327498; https://hal.archives-ouvertes.fr/hal-03327498/document; https://hal.archives-ouvertes.fr/hal-03327498/file/Does%20a%20strong%20pycnocline%20impact%20organic-V1.pdf; https://doi.org/10.1016/j.crte.2008.10.002

International audience The Orca Basin (an intraslope depression located in the Gulf of Mexico) collects sedimentary particles of terrestrial origin (clastic and organic particles mainly supplied by the Mississippi River) and of marine origin (biogenic productivity). The basin is partly filled with dense brines leached from salt diapirs cropping out on the sea floor, and is permanently stratified. A strong pycnocline induces anoxic bottom conditions, expectedly favorable to organic matter (OM) preservation. Here, we report on OM in the upper 750 cm below sea floor of Core