Lateral variations of pressure-temperature evolution in non-cylindrical orogens and 3-D subduction dynamics: the Betic-Rif Cordillera example

This paper is a contribution of the Orogen project funded by Total, BRGM and CNRS-INSU and it benefited from numerous discussions with the Orogen community. The 40Ar/39Ar facility at ISTO was funded and is supported by the ERC Advanced grant RHEOLITH, the LABEX project VOLTAIRE (ANR-10-LABX-100-01), the Région Centre project ARGON, and the project EQUIPEX PLANEX (ANR-11-EQPX-0036). We would to thank the guest-editor David Pedreira and the two reviewers, Juan Soto and André Michard for a really extensive analysis of our manuscript, which is obviously in better shape now. Special thanks are due to Federico Rossetti who commented on an early version of the manuscript. ; The long-term Pressure-Temperature-time-deformation (P-T-t-d) evolution of the internal zones of orogens results from complex interactions between the subducting lithosphere, the overriding plate and the intervening asthenosphere. 2-D numerical models successfully reproduce natural P-T-t-d paths, but most orogens are non-cylindrical and the situation is far more complex due to 3-D pre-orogenic inheritance and 3-D subduction dynamics. The Mediterranean orogens are intrinsically non-cylindrical. Their 3-D geometry results from the complex shape of the Eurasian and African margins before convergence and from the dynamics of slab retreat and tearing leading to strongly arcuate belts. More than many other segments, the Betic-Rif belt is archetypal of this behavior. A synthesis of the tectonometamorphic evolution of the Internal Zones, also based on recent findings by our group in the framework of the Orogen Project (Alboran domain, including the Alpujarride-Sebtide and Nevado-Filabride complexes) shows the relations in space and time between tectonic and P-T evolutions. The reinterpretation of the contact between peridotite massifs and Mesozoic sediments as an extensional detachment leads to a discussion of the geodynamic setting and timing of mantle exhumation. Based on new Ar-40/Ar-39 ages in the Alpujarride-Sebtide complex and a discussion of ...