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

Nicolas Tribovillard , Viviane Bout‑roumazeilles (1) , Thomas Sionneau , Montero Serrano , Armelle Riboulleau , François Baudin

1 LOG - Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187

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

Domaines: Sciences de l'environnement; Planète et Univers [physics]; Sciences du Vivant [q-bio]; Physique [physics]

Nicolas Tribovillard, Viviane Bout‑roumazeilles, Thomas Sionneau, Montero Serrano, Armelle Riboulleau, et al.. Does a strong pycnocline impact organic-matter preservation and accumulation in an anoxic setting? The case of the Orca Basin, Gulf of Mexico. Comptes Rendus. Géoscience, 2009, 341 (1), pp.1-9. ⟨10.1016/j.crte.2008.10.002⟩. ⟨hal-03327498⟩