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.
Highlights
Jurassic Tethys segmentation in the Eurasia–Africa plate boundary has been proposed from plate reconstruction models [1,2], but the location, extent, and evolution of these segments is uncertain owing to their obliteration during the Alpine orogeny
The filtered Bouguer gravity anomalies (Figure 3) reflect those relevant structures producing gravity anomalies with wavelengths of
The diffuse character of the IAPB is related to (i) the complex tectonic pattern resulting from the convergence between the Iberia and Africa margins with its inherited en-echelon geometry, (ii) the arcuate slab roll-back of the Alboran segment with the formation of an accretionary wedge in the Gulf of Cadiz and the back-arc Alboran from the work of [16] and the evolution of the Betic-Rif orogen from the work of [4] incorporating recent works focusing on the different plate boundary segments [22,23,24,43]
Summary
Jurassic Tethys segmentation in the Eurasia–Africa plate boundary has been proposed from plate reconstruction models [1,2], but the location, extent, and evolution of these segments is uncertain owing to their obliteration during the Alpine orogeny. The opening of the Central Atlantic during the Early Jurassic caused the eastward migration of Africa relative to Iberia, generating the Ligurian–Tethys domain, which was formed by several transtensive and highly extended continental segments transitioning to oceanic lithosphere further east [2]. Transtension in the Ligurian–Tethys ceased during the Early Cretaceous, when the Mid-Atlantic ridge propagated northwards along the Newfoundland–Iberia margin, triggering the eastward motion of the Iberian plate. A the 5 km high seamount the Tagus and the Horseshoe abyssal plains; the Gulf of. A back-arc basin formed by the roll-back of the Ligurian–Tethys subducting slab and the migration of the Alboran basin, the Betic–Rif front. A back-arc basin formed by the roll-back of the Ligurian–Tethys subducting slab and the migration of the Betic–Rif front
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