Long-lasting transcurrent tectonics in SWAlps evidenced by Neogene to present-day stress fields.
- Others:
- Géoazur (GEOAZUR 6526) ; Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Nice Sophia Antipolis (1965 - 2019) (UNS) ; COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-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)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)
- Institute of Oceanography [Taipei] ; National Taiwan University [Taiwan] (NTU)
- 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])
- IFP Energies nouvelles (IFPEN) ; IFP Energies nouvelles (IFPEN)
Description
The SW Alps are an active orogen undergoing intra-mountainous extension and peripheral compression. We discuss the significance of syn-orogenic extension based on a comparison of paleo-stress derived from faultslip data inversion reflecting the long-term (b12 Ma) evolution of SW Alps and the present-day stress state obtained by the inversion of the focal mechanisms of the last 30-years seismicity. The resulting stress states of long-term and active tectonic regimes are in good agreement, showing that extension accompanies strike-slip and reverse faulting in the southern part of the belt. The extensional deformation regime is limited to specific tectonic domains that can be interpreted as 'transitional' between pure strike-slip segments where the deformation concentrates on inherited ductile shear zones that were formed between 32° and 20 Ma ago. We thus propose that the extensional deformation in the SW Alps can be defined as a local deformation in a pull-apart type domain (High Durance - Jausiers area) or above slowly exhuming internal massifs (Dora Maira - Ivrea Body) along a curved boundary between the slowly rotating Apulian block and the relatively immobile Western Europe. The transcurrent fault system merges into a compressional front along the Mediterranean - Ligurian coast mainly to the east of San Remo.
Abstract
International audience
Additional details
- URL
- https://hal-ifp.archives-ouvertes.fr/hal-01068698
- URN
- urn:oai:HAL:hal-01068698v1
- Origin repository
- UNICA