Mass-transport deposits and fluid venting in a transform margin setting, the eastern Demerara Plateau (French Guiana)
|Author(s)||Pattier France1, 2, Loncke L.1, Gaullier V.1, Basile C.3, Maillard Alexandre4, Imbert Patrice5, Roest Walter2, Vendeville B. C.6, Patriat Martin2, Loubrieu Benoit2|
|Affiliation(s)||1 : Univ Perpignan, Ctr Format & Rech Environm Mediterraneens, UMR 5110, F-66860 Perpignan, France.
2 : IFREMER, Ctr Brest, Inst Carnot, EDROME,UR Geosci Marines, F-29280 Plouzane, France.
3 : Univ Grenoble 1, CNRS, Observ Sci Univers Grenoble, ISTerre,UMR 5275, F-38400 St Martin Dheres, France.
4 : Univ Toulouse 3, GET, OMP, F-31400 Toulouse, France.
5 : Total CSTJF, F-64000 Pau, France.
6 : Univ Sci & Technol Lille 1, UFR Sci Terre, UMR Geosyst 8157, F-59655 Villeneuve Dascq, France.
|Source||Marine And Petroleum Geology (0264-8172) (Elsevier Sci Ltd), 2013-09 , Vol. 46 , P. 287-303|
|WOS© Times Cited||10|
|Keyword(s)||Fluid ascent, Pockmarks, MTDs, Transform margin, Demerara Plateau|
|Abstract||The eastern Demerara Plateau offshore French Guiana was surveyed in 2003 during the GUYAPLAC cruise (multibeam bathymetry and acoustic imagery, 6-channel seismic reflection and 3.5 kHz echo-sounding). The data show the "post-transform" Cenozoic that the series located on the outer part of the plateau (below c. 2000 m) contain at least twelve stacked mass transport deposits (MTDs) that have recorded a history of large-scale slope failure, as well as two main normal fault sets that provide possible pathways for upward fluid migration through the series, reaching at high as the uppermost MTDs. Seabed data show that the area above the failures is characterized by circular-to-elongate (slope-parallel) depressions interpreted as fluid seeps (pockmarks), some of them have been modified by along slope currents. We suggest that the development of the MTDs to results from the combinaiton of the presence of fluid overpressure at depth the geometry of the margin's deep structure, in particular the existence of a 'free borderlateral border' on the outermost plateau. Our results also emphasise the role of stratigraphic decollements within the Cenozoic series.|