FN Archimer Export Format
PT J
TI Along-arc segmentation and interaction of subducting ridges with the Lesser Antilles Subduction forearc crust revealed by MCS imaging
BT 
AF LAIGLE, Mireille
   BECEL, Anne
   DE VOOGD, Beatrice
   SACHPAZI, Maria
   BAYRAKCI, Gaye
   LEBRUN, Jean-Frederic
   EVAIN, Mikael
AS 1:1,6;2:1,2;3:3;4:4;5:1,7;6:5;7:6,7;
FF 1:;2:;3:;4:;5:;6:;7:PDG-REM-GM-LGG;
C1 CNRS, UMR 7154, Inst Phys Globe Paris, Sorbonne Paris Cite, Paris, France.
   Aix Marseille Univ, CNRS, UMR 6635, CEREGE, F-13545 Aix En Provence 4, France.
   Univ Pau & Pays Adour, CNRS, FR 2952, IPRA Inst Pluridisciplinaire Rech Appl Domaine Ge, F-64013 Pau, France.
   Natl Observ Athens, Geodynam Inst, Athens, Greece.
   Univ Antilles Guyane, EA4098, Lab Rech Geosci & Energie, Pointe A Pitre 97159, Guadeloupe.
   Univ Nice Sophia Antipolis, CNRS, Observ Cote Azur, Geoazur, F-06560 Valbonne, France.
   IFREMER, Ctr Brest, Lab Geodynam & Geophys, F-29280 Plouzane, France.
C2 CNRS, FRANCE
   UNIV AIX MARSEILLE, FRANCE
   UNIV PAU & PAYS ADOUR, FRANCE
   NATL OBSERV ATHENS, GREECE
   UNIV ANTILLES GUYANE, FRANCE
   UNIV NICE, FRANCE
   IFREMER, FRANCE
SI AUTRE
   BREST
SE AUTRE
   PDG-REM-GM-LGG
IN WOS Ifremer jusqu'en 2018
   copubli-france
   copubli-europe
   copubli-univ-france
IF 2.866
TC 21
TU Aix-Marseille université
   Centre national de la recherche scientifique
   Collège de France
   Institut National de l'Information Géographique et Forestière
   Institut de physique du globe
   Institut de recherche pour le développement
   Observatoire de la côte d'azur
   Université Nice - Sophia-Antipolis
   Université Paris Diderot
   Université Pierre et Marie Curie
   Université de La Réunion
   Université de Pau et des Pays de l'Adour
   Université des Antilles
AC "Thales Was Right" Seismic Reflection working group
UR https://archimer.ifremer.fr/doc/00139/25003/23109.pdf
LA English
DT Article
CR OBSANTILLES
   SISMANTILLES
   SISMANTILLES 2
BO Antea
   Le Nadir
   L'Atalante
DE ;Lesser Antilles Subduction Zone;Reflection seismics;Deep outer forearc crust;Backstop;Seismogenic megathrust fault
AB We present the results from a new grid of deep penetration multichannel seismic (MCS) profiles over the 280-km-long north-central segment of the Lesser Antilles subduction zone. The 14 dip-lines and 7 strike-lines image the topographical variations of (i) the subduction interplate décollement, (ii) the top of the arcward subducting Atlantic oceanic crust (TOC) under the huge accretionary wedge up to 7 km thick, and (iii) the trenchward dipping basement of the deeply buried forearc backstop of the Caribbean upper plate.  The four northernmost long dip-lines of this new MCS grid reveal several-kilometres-high topographic variations of the TOC beneath the accretionary wedge offshore Guadeloupe and Antigua islands. They are located in the prolongation of those mapped on the Atlantic seafloor entering subduction, such as the Barracuda Ridge. This MCS grid also provides unexpected evidences on huge along-strike topographical variation of the backstop basement and of the deformation style affecting the outer forearc crust and sediments. Their mapping clearly indicates two principal areas of active deformation in the prolongation of the major Barracuda and Tiburon ridges and also other forearc basement highs that correspond to the prolongation of smaller oceanic basement highs recently mapped on the Atlantic seafloor. Although different in detail, the two main deforming forearc domains share similarities in style.  The imaged deformation of the sedimentary stratification reveals a time- and space-dependent faulting by successive warping and unwarping, which deformation can be readily attributed to the forearc backstop sweeping over the two obliquely-oriented elongated and localized topographical ridges. The induced faulting producing vertical scarps in this transport does not require a regional arc-parallel extensional regime as proposed for the inner forearc domain, and may support a partitioned tectonic deformation such as in the case of an outer forearc sliver.  A contrasted reflectivity of the sedimentary layering at the transition between the outer forearc and accretionary domains was resolved and used to define the seaward edge of the outer forearc basement interpreted as being possibly a proxy to the updip limit of the interplate seismogenic zone. Its mapping documents along-arc variations of some tens of kilometres the subduction backstop with respect to the negative gravity anomaly commonly taken as marking the subduction trench. With the exception of the southernmost part, the newly mapped updip limit reaches 25 km closer to the trench, thus indicating a possible wider seismogenic zone over almost the whole length of the study area.
PY 2013
PD SEP
SO Tectonophysics
SN 0040-1951
PU Elsevier Science Bv
VL 603
UT 000324450100003
BP 32
EP 54
DI 10.1016/j.tecto.2013.05.028
ID 25003
ER

EF