FN Archimer Export Format
PT J
TI Origin of an enigmatic regional Mio-Pliocene unconformity on the Demerara plateau
BT 
AF PATTIER, France
   LONCKE, L.
   IMBERT, Patrice
   GAULLIER, V.
   BASILE, C.
   MAILLARD, Alexandre
   ROEST, Walter
   PATRIAT, Martin
   VENDEVILLE, B. C.
   MARSSET, Tania
   BAYON, Germain
   CATHALOT, Cecile
   CAPRAIS, Jean-Claude
   BERMELL, Sylvain
   SOTIN, Christine
   HEBERT, Bertil
   MERCIER DE LEPINAY, Marion
   LEBRUN, J. F.
   MARCAILLOU, B.
   HEURET, A.
   DROZ, Laurence
   GRAINDORGE, David
   POETISI, E.
   BERRENSTEIN, H.
AS 1:1,2;2:1;3:3;4:4;5:5;6:6;7:2;8:2;9:4;10:2;11:2;12:2;13:2;14:2;15:7;16:7;17:7,8;18:9;19:9;20:9;21:10;22:10;23:11;24:11;
FF 1:PDG-REM-GM-LGG;2:;3:;4:;5:;6:;7:PDG-REM-GM-LGG;8:PDG-REM-GM-LGG;9:;10:PDG-REM-GM-LES;11:PDG-REM-GM-LGM;12:PDG-REM-GM-LGM;13:PDG-REM-EEP-LEP;14:PDG-REM-GM-CTDI;15:;16:;17:;18:;19:;20:;21:;22:;23:;24:;
C1 Univ Perpignan Via Domitia, Ctr Format & Rech Environnements Mediterraneens, UMR 5110, F-66860 Perpignan, France.
   UR Geosci Marines, Inst Carnoilfremer EDROME, Ctr Brest, IFREMER, F-29280 Plouzane, France.
   Total CSTJF, F-64000 Pau, France.
   Univ Lille 1, CNRS, Lab Oceanol & Geosci, UMR 8187, F-59655 Villeneuve Dascq, France.
   Univ Grenoble 1, Observ Sci Univ Grenoble, ISTerre, UMR CNRS 5275, F-38400 St Martin Dheres, France.
   Univ Toulouse 3, GET OMP, F-31400 Toulouse, France.
   CEFREM, Perpignan, France.
   TOTAL SA, Paris, France.
   Univ Antilles Guyane, St Claude, France.
   Univ UBO Brest, Brest, France.
   Univ Paramaribo, Paramaribo, Surinam.
C2 UNIV PERPIGNAN, FRANCE
   IFREMER, FRANCE
   TOTAL, FRANCE
   UNIV LILLE, FRANCE
   UNIV GRENOBLE, FRANCE
   UNIV TOULOUSE, FRANCE
   CEFREM, FRANCE
   TOTAL, FRANCE
   UNIV ANTILLES GUYANE, FRANCE
   UBO, FRANCE
   UNIV PARAMARIBO, SURINAME
SI BREST
   NOUMEA
SE PDG-REM-GM-LGG
   PDG-REM-GM-LES
   PDG-REM-GM-LGM
   PDG-REM-EEP-LEP
   PDG-REM-GM-CTDI
UM LGO
IN WOS Ifremer jusqu'en 2018
   copubli-france
   copubli-univ-france
   copubli-int-hors-europe
   copubli-sud
IF 2.503
TC 8
UR https://archimer.ifremer.fr/doc/00271/38193/36735.pdf
LA English
DT Article
CR GUYAPLAC
   IGUANES
BO L'Atalante
DE ;Unconformity;Hydrate pockmark;Slide;Contourite;Valley;Canyon;Demerara plateau
AB The Demerara plateau, located offshore French Guiana and Suriname, is part of a passive transform continental margin particularly prone to develop slope instabilities, probably in relation to the presence of a free distal border along its steep continental slope. Slope failure occurred at different periods (Cretaceous to Neogene) and shows an overall retrogressive evolution through time. Upslope these failure headscarp, an enigmatic regional MioPliocene unconformity has been discovered through the interpretation of new academic and industrial datasets. The aim of this work is to describe and understand the origin of this surface. Our analysis shows that this unconformity is made of a series of valleys that cross-cut sedimentary strata. Each one of these valleys has a short lateral extent and is closed along two perpendicular directions, which suggests that it could correspond to a highly meandering system, or to some sub-circular depressions. The infill of these features is equivalent to the regional stratigraphic strata found outside the structures, but in a subdued position. This seems to imply that the structures have originated by a local loss of sediments at their base or by sliding processes. Furthermore, these depressions intersect each other through time, while migrating progressively downslope. We discuss a series of hypotheses that try to explain the onset and evolution of these depressions forming the Mio-Pliocene unconformity (Canyons? Slope failures? Contourite moats? Hydrate pockmarks?). Having established that these structures are depressions formed by collapse, and have many similarities with structures recently described in the literature as pockmarks associated with gas hydrate dissolution, we favor this hypothesis. We propose that these hydrate pockmarks form with a mass failure that was triggered by fluid-overpressure development at the base of the hydrate stability zone.
PY 2015
PD JUN
SO Marine Geology
SN 0025-3227
PU Elsevier Science Bv
VL 365
UT 000355061400003
BP 21
EP 35
DI 10.1016/j.margeo.2015.04.001
ID 38193
ER

EF