Echofacies interpretation of Pleistocene to Holocene contourites on the Demerara plateau and abyssal plain
Type | Article | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Date | 2021-05 | ||||||||||||
Language | English | ||||||||||||
Author(s) | Tallobre Cédric1, Loncke Lies1, Droz Laurence2, Marsset Tania3, Uusõue Mirjam4, Roest Walter3, Fanget Anne-Sophie1, Bassetti Maria-Angela1, Giresse Pierre1, Bayon Germain3 | ||||||||||||
Affiliation(s) | 1 : Université de Perpignan Via Domitia, Centre de Formation et de Recherche sur les Environnements Méditerranéens (CEFREM), UMR 5110, Perpignan, France.. 2 : Université de Bretagne Occidentale (UBO)/UMR 6538 du CNRS Domaines Océaniques, Plouzané, France.. 3 : IFREMER, Unité de Recherche Géosciences Marines, Plouzané, France.. 4 : Tartu Observatory, Observatooriumi 1, Tõravere, 61602 Tartumaa, Estonia.. |
||||||||||||
Source | Interpretation-a Journal Of Subsurface Characterization (2324-8858) (Society of Exploration Geophysicists), 2021-05 , Vol. 9 , N. 2 , P. SB49-SB65 | ||||||||||||
DOI | 10.1190/INT-2020-0159.1 | ||||||||||||
WOS© Times Cited | 1 | ||||||||||||
Abstract | Off French Guiana and Surinam, NADW and AABW oceanic currents contour the Demerara marginal plateau, which promotes the formation of contourites. We have studied these contourites thanks to a new compilation of high-resolution sub-bottom profiles calibrated by sedimentary cores. The echo-facies and isopach maps we constructed highlight a sedimentary distribution parallel to the isobaths. The presence of moats along the slope is confirmed by the observation of parallel, elongated, sedimentary depleted zones and echo-facies strongly affected by diffraction hyperbola and transparent echo-facies. We interpret these features to be related to eroded slopes and Mass Transport Deposits. In contrast, the sedimentary drifts we mapped are characterized by elongated and thick slope-parallel depocentres displaying bedded echo-facies with wave-like bedforms. According to our interpretation, they result from interactions between currents and the seafloor. Seismic wipe-outs frequently affect those drifts, possibly resulting from high water or organic contents. |
||||||||||||
Full Text |
|