FN Archimer Export Format
PT J
TI Caribbean plate boundaries control on the tectonic duality in the back‐arc of the Lesser Antilles subduction zone during the Eocene
BT 
AF Cerpa, N. G.
   Hassani, R.
   Arcay, D.
   Lallemand, S.
   Garrocq, C.
   Philippon, M.
   Cornée, J.‐J.
   Münch, P.
   Garel, F.
   Marcaillou, B.
   Mercier de Lépinay, B.
   Lebrun, J.‐F.
AS 1:1,2;2:2;3:1;4:1;5:1;6:3;7:3;8:1;9:1;10:2;11:2;12:3;
FF 1:;2:;3:;4:;5:;6:;7:;8:;9:;10:;11:;12:;
C1 Geosciences Montpellier University de Montpellier CNRS Université des Antilles Place Eugène Bataillon34095 Montpellier, France
   Geoazur Université Côte d’Azur CNRS Observatoire de la Côte d’Azur IRD 250 Avenue Albert Einstein06560 Valbonne ,France
   Geosciences Montpellier Université des Antilles Université de Montpellier CNRS Campus Fouillole Pointe‐à‐Pitre Guadeloupe (FWI) ,France
C2 UNIV MONTPELLIER, FRANCE
   UNIV NICE, FRANCE
   UNIV ANTILLES, FRANCE
IF 5.261
TC 0
UR https://archimer.ifremer.fr/doc/00733/84513/89597.pdf
   https://archimer.ifremer.fr/doc/00733/84513/89598.pdf
LA English
DT Article
CR ANTITHESIS 3
   ANTITHESIS LEG1
   ANTITHESIS LEG2
   ANTITHESIS2 DEPLO
   ANTITHESIS2 RECUP
   GARANTI
   GARANTI 2
BO Pourquoi pas ?
   L'Atalante
   Antea
DE ;subduction;trench curvature;back-arc tectonic regime;numerical modeling;lesser antilles subduction zone;Caribbean plate
AB The Eocene tectonic evolution of the easternmost Caribbean Plate (CP) boundary, i.e. the Lesser Antilles subduction zone (LASZ), is debated. Recents works shed light on a peculiar period of tectonic duality in the arc/back-arc regions. A compressional-to-transpressional regime occurred in the north, while rifting and seafloor spreading occurred in Grenada basin to the south. The mechanism for this strong spatial variation and its evolution through time has yet to be established. Here, using 3-D subduction mechanical models, we evaluate whether the change in the trench-curvature radius at the northeast corner of the CP could have modulated the duality. We assume asymmetrical CP boundaries at the north (from east to west: oblique subduction to strike-slip) and at the south (subduction-transform edge propagator-like behavior). Regardless of the imposed trench curvature, the southern half of our modeled CP undergoes a NW-to-W-oriented extension due to the tendency of the southernmost part of the South-America oceanic slab to rollback. In contrast, the tectonic regime in the northeast corner of the CP depends on the trench-curvature radius. A low radius promotes transtension-to-transpression, with a NE-oriented compressive component of the principal stress. A high radius largely reduces the compressive component and promotes an extensional regime similar to that in the south. We thus propose that an initially low-curvature radius of the NE-LASZ triggered the tectonic N-S duality in the Eocene and led to an ephemeral period of transpression/compression at the north. However, an additional mechanism might have been required to locally enhance compression. 
PY 2021
PD NOV
SO Tectonics
SN 0278-7407
PU American Geophysical Union (AGU)
VL 40
IS 11
UT 000723093200008
DI 10.1029/2021TC006885
ID 84513
ER

EF