Integrated modeling of the crust and mantle structure in the Zagros fold and thrust belt and the mesopotamian foredeep

The Zagros mountains formed by collision between Arabian and Eurasian plates from Miocene times. The region is characterized by intermediate seismicity, a low mantle velocity, a deep foreland basin, and an irregularly folded sedimentary cover. Despite extensive acquisition of geophysical data major unknowns are related to i) the nature of the crustal deformation during collision and the resulting crustal structure; ii) the existence of a mantle root and the possible strain partitioning between crust and mantle lithosphere; and iii) the basement deflection caused by the building of the Zagros mountains and the associated deep geometry of the foreland basin. These items are addressed in two ways. An integrated approach, combining the use of gravity, geoid and absolute elevation allows us to infer the 3D regional crustal and lithospheric structure. The resolution of the gravity inverse problem for that lithospheric configuration allow us to separate the regional and local field components which, in turn, allows for a more detailed 2D lithospheric modelling along selected geotransects. These geotransects are constrained by existing seismic profiles, surface elevation, gravity and geoid data. The crustal and lithospheric structure is modelled by using a numerical code that simultaneously solves the geopotential, lithostatic, and heat transport equations.