Antonio Villaseñor, Ana M. Negredo, Stéphane Guillot, Anne Replumaz, Peter van der Beek, Laboratoire de Géodynamique des Chaines Alpines (LGCA), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut des Sciences de la Terre (ISTerre), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR), Department of Geophysics [Madrid], Universidad Complutense de Madrid [Madrid] (UCM), Institute of Earth Sciences Jaume Almera, Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Universidad Complutense de Madrid = Complutense University of Madrid [Madrid] (UCM), and Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)
International audience; The long-lasting collision between India and Asia has resulted in crustal and lithospheric deformation of both continents, providing unequalled opportunities to evaluate their long-term mechanisms of deformation. We have quantified a crustal mass budget for the collision by comparing the present-day and initial crustal volumes of the Indian and Asian continents involved in the collision. Initial crustal thickness was estimated from the non-deformed parts of the continents, whereas their initial extent was mapped from their contours at the onset of collision, using seismic tomography. We quantify the portion of the initial crustal thickness of both continents stored within the currently thickened crust or redistributed due to extrusion. For the Indian continent, this portion amounts to about 19 km, far lower than the mean observed present-day crustal thickness of the Indian craton of about 38 km. We conclude that between 40 and 50% of Indian crust has been recycled into the mantle by continental subduction, corresponding to a decoupling level at about 15–19 km depth. For the Asian continent, the estimated crustal thickness stored during collision is about 33 km, close to the initial Asian crustal thickness. We estimate that only 3% of the Asian crust was recycled into the mantle. This corresponds to one episode of continental subduction, occurring most probably soon after the initiation of collision along the Bangong suture. We identify the related slab using seismic tomography. The strong contrast between India and Asia implies an age-dependent capacity of the continental crust to be recycled into the mantle. This result has to be taken into account for further analysis of global crustal recycling during Earth's history.