Evidence of Segmentation in the Iberia–Africa Plate Boundary: A Jurassic Heritage?

Abstract

The present structure of the Iberia−Africa plate boundary between the Gorringe Bank and the Algerian Basin is characterized by a highly segmented geometry and diffused seismicity. Filtered Bouguer gravity data show conspicuous highs coinciding with the Gorringe Bank, the Guadalquivir−Portimao Bank, and the Ronda/Beni−Bousera massifs, reflecting the current geometry of the plate boundary segments. The Africa−Eurasia Alpine convergence produced crustal-scale thrusting in the Atlantic segments and roll-back subduction in the Ligurian−Tethys segments. Despite the growing consensus that the Gorringe and the Guadalquivir−Portimao Banks resulted from tectonic inversion of hyperextended margin structures inherited from the Early Jurassic, this heritage is more debatable for the Ronda/Beni−Bousera massifs lacking models linking the Atlantic and Mediterranean realms. On the basis of gravity analysis combined with plate reconstruction models, geological cross-sections, and recent local tomography, we infer a strong Jurassic heritage of the present-day segmentation and substantiate a comprehensive tectonic evolution model of the Iberia−Africa plate boundary since the Early Jurassic to Recent that includes the Atlantic and the Mediterranean domains.

Keywords

• gravity modelling
• hyper-extended margin segments
• tectonic reconstruction
• Atlantic–Mediterranean domains