Caribbean plate boundaries control on the tectonic duality in the back-arc of the Lesser Antilles subduction zone during the Eocene

Autor: N. G. Cerpa, R. Hassani, D. Arcay, S. Lallemand, C. Garrocq, M. Philippon, J.‐J. Cornée, P. Münch, F. Garel, B. Marcaillou, B. Mercier de Lépinay, J.‐F. Lebrun
Přispěvatelé: Géosciences Montpellier, Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Géoazur (GEOAZUR 7329), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Université des Antilles (Pôle Guadeloupe), Université des Antilles (UA), (ANR -17- 31 CE (ANR-17-31 CE-0009), ANR-17-CE31-0009,GAARAnti,Pont terrestre 'GAARlandia' vs voies de dispersion à travers les Petites Antilles–Couplage entre dynamique de la subduction et processus de l'évolution des espèces dans le domaine des Caraïbes.(2017), Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), (ANR-17-31 CE(ANR-17-31 CE-0009), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Université des Antilles (UA)-Centre National de la Recherche Scientifique (CNRS)
Rok vydání: 2022
Předmět:
Zdroj: Tectonics
Tectonics, 2021, 40 (11), pp.e2021TC006885. ⟨10.1029/2021TC006885⟩
Tectonics, American Geophysical Union (AGU), 2021, 40 (11), pp.e2021TC006885. ⟨10.1029/2021TC006885⟩
Tectonics (0278-7407) (American Geophysical Union (AGU)), 2021-11, Vol. 40, N. 11, P. e2021TC006885 (22p.)
ISSN: 0278-7407
1944-9194
DOI: 10.31223/x5331r
Popis: 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 compressive-to-transpressive 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 always undergoes a NWto-W-oriented extension due to the tendency of the southernmost part of the South-America 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 trench-curvature largely reduces the compressive component and promotes an extensive 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, although an additional mechanism might have been required to locally enhance compression
Databáze: OpenAIRE
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