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A detailed crust to upper mantle structure: Comparison between Algerian and Alboran domains in the Western Mediterranean
  • Ajay Kumar
Ajay Kumar
Group of Dynamics of the Lithosphere, Institute of Earth Sciences Jaume Almera (ICTJA-CSIC), Barcelona, Spain

Corresponding Author:[email protected]

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Abstract

We present a comparison of the detailed present-day crust to upper-mantle (400km) structure in the Western Mediterranean along two transects in Alboran and Algerian domains. The transect across the Alboran domain is NW-SE oriented crossing the Betics and the Alboran Basin and the northern margin of Africa between the Tell and Rif mountains. The Algerian domain transect is also NW-SE oriented crossing the Valencia Trough, the Balearic Promontory, the Algerian basin and ending in the Tell-Atlas Mountains in the northern margin of Africa. The structure is computed using integrated geophysical-petrological modelling tool (LitMod2D) which combines petrological, geochemical and geophysical dataset in a self-consistent framework. We model thermal, compositional, density and seismological structure, also incorporating slabs imaged by seismic tomography, constrained by simultaneously fitting elevation, gravity, geoid, surface heat flow and seismic tomography models to reduce the uncertainties in the modelling. Preliminary results suggest that crust is thickest beneath the Betics and thins beneath the Alboran basin within a distance of ~100 km. Farther SE, crust gradually thickens beneath the north margin of Africa, between Tell and Rif mountains over ~300 km distance. The LAB shows a similar trend though it is affected by the presence of the slab underneath Betics. For the Algerian domain transect, maximum crustal thickness occurs beneath the Tell-Atlas Mountains with noticeable variations across the Algerian basin, Balearic Promontory and Valencia Trough, the LAB showing a similar tendency. Comparing the modelled geometries suggests that both transects have opposite trends with the deepest Moho and LAB in the NW side of the Alboran transect and in the SE side of the Algerian transect, imposing important restrictions on the geodynamic evolution of the Western Mediterranean.