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Slope instabilities from echo-character mapping along the French Guiana transform margin and Demerara abyssal plain

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  • معلومة اضافية
    • Contributors:
      Institut de Modélisation et d'Analyse en Géo-Environnement et Santé (IMAGES); Université de Perpignan Via Domitia (UPVD); Domaines Océaniques (LDO); Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Observatoire des Sciences de l'Univers-Institut d'écologie et environnement-Centre National de la Recherche Scientifique (CNRS); Laboratoire de Géodynamique des Chaines Alpines (LGCA); Observatoire des Sciences de l'Univers de Grenoble (OSUG); Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS); Unité Géosciences Marines (GM); Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER); French Research Program ‘‘GDR Marges''
    • بيانات النشر:
      HAL CCSD
      Elsevier
    • الموضوع:
      2009
    • Collection:
      Université de Perpignan: HAL
    • نبذة مختصرة :
      International audience ; The French Guiana transform margin and Demerara abyssal plain have been recently surveyed in the framework of the EXTRAPLAC French Program of extension of the continental shelf (Guyaplac survey, Ifremer-IFP–SHOM-IPEV). Based on the interpretation of some of the data collected during the Guyaplac survey (Simrad-EM12 multibeam bathymetric data, backscatter imagery, and 3.5 kHz profiles), the area can be divided into three morphostructural domains. (1) The western Guiana margin, including a part of the Demerara plateau, an important bathymetric relief prolonging the continental platform off Guiana and Surinam. This domain is bounded by (1a) the NW– SE trending northern border of the Demerara plateau which appears quite steep and corresponds to a transform segment of the margin, (1b) the N–S eastern border of the Demerara plateau which corresponds to a divergent segment of the margin. The Demerara plateau shows a segmented morphology, lowslope gradients, and a very rough surface (ripples perpendicular to the slope direction). NNW–SSE structural steps seem to correspond to collapses of 100 km long blocs towards the east. Slumps initiate along these directions. The observed rough bathymetry seems to be related to creeping processes. At a greater scale (seismic data), this part of the margin has been totally destabilized (numerous imbricate transparent masses rooted at about 0.5 s.t.w.t.t. belowseafloor). TheNW–SE trending northern border of the Demerara plateau corresponds to a cliff-like continental slope, probably slightly smoother than other transform margins (Ghana/coˆte d'Ivoire margin). The N–S eastern border of Demerara plateau is characterized by numerous small-scale imbricate slumps. Some of these failures seem to be emplaced in the prolongation of the NNW–SSE structural steps identified on the Demerara plateau. (2) The eastern Guiana margin corresponds to a NW–SE oriented gullied transform margin segment. The associated continental slope is very steep and characterized by numerous ...
    • الرقم المعرف:
      10.1016/j.marpetgeo.2008.02.010
    • الدخول الالكتروني :
      https://insu.hal.science/insu-00411151
      https://insu.hal.science/insu-00411151v1/document
      https://insu.hal.science/insu-00411151v1/file/publication-6856.pdf
      https://doi.org/10.1016/j.marpetgeo.2008.02.010
    • Rights:
      info:eu-repo/semantics/OpenAccess
    • الرقم المعرف:
      edsbas.59B5F2C3