A large body of multidisciplinary data suggest regional cooling rates of c. 500 degrees C/m.y. for high-grade metamorphic nappe complexes within the Alpine belt of the Betic Cordilleras within the period 22-17 Ma (Early Miocene, latest Aquitanian-Burdigalian), followed by much slower cooling in the period 19-6 Ma, down to c. 3 degrees C/m.y. from 16 to 6 Ma. The constraining thermochronometric information covers a temperature range of c. 700 degrees C to 25 degrees C and is from: (a) isotopic thermochronometers (muscovite- and biotite-WR Rb-Sr, muscovite and biotite 40Ar/39Ar, biotite K-Ar, and WR Rb-Sr); (b) apatite and zircon fission track studies; (c) paleontologic dates of foraminifera and nannoplankton from nappe-sealing sedimentary rocks; and (d) provenance studies, appearance of elastic material derived from these same nappe complexes, in dated sequences in (foreland) basins flanking the orogen, The period of forced cooling may be explained by tectonic unroofing by extensional tectonics, Cooling would have been by loss of insulation due to removal of overlying rock complexes and by superposition upon cooler rocks. The period of extensional tectonics and very fast cooling was produced by fast regional rock uplift triggered by detachment, shortly before 22 Ma, of subducted Mesozoic Tethys lithosphere representing the NW-dipping Betic-Rif subduction zone system which would represent the backbone of Betic-Rif orogeny. The Tethys realm comprised continental areas; opening of the North Atlantic and eastward drift of Iberia/Europe may have induced failure and initiated subduction in the weakest places, among which the Betic-Rif suture. Alpine orogeny in the western Mediterranean would thus mainly be conditioned by eastward drift of Iberia/Europe relative to North America, rather than by N-S convergence between Africa and Iberia/Europe, Plate kinematic reconstructions for the North Atlantic realm suggest that N-S-directed Africa-Iberia convergence was only minor and resulted in Top-northward structures. The present E-W grain of the Betic belt was initiated by the N-S convergence and emphasized during late-stage morphogenesis. Post-orogenic Neogene volcanics in the Betic-Alboran region are concentrated above the sinking lithospheric slab, which position is outlined by recent delay-time seismic tomography. The volcanics are suggested to have been formed from magmas generated in the overlying Betic lithosphere by anatexis in a HT regime caused by uplift of isotherms (decompression melting) and diapiric inflow of hot sub-lithospheric mantle in the widening gap above the sinking slab. A large body of multidisciplinary data suggest regional cooling rates of c. 500 degrees C/m.y. for high-grade metamorphic nappe complexes within the Alpine belt of the Betic Cordilleras within the period 22-17 Ma (Early Miocene, latest Aquitanian-Burdigalian), followed by much slower cooling in the period 19-6 Ma, down to c. 3 degrees C/m.y. from 16 to 6 Ma. The constraining thermochronometric information covers a temperature range of c. 700 degrees C to 25 degrees C and is from: (a) isotopic thermochronometers (muscovite- and biotite-WR Rb-Sr, muscovite and biotite 40Ar/39Ar, biotite K-Ar, and WR Rb-Sr); (b) apatite and zircon fission track studies; (c) paleontologic dates of foraminifera and nannoplankton from nappe-sealing sedimentary rocks; and (d) provenance studies, appearance of elastic material derived from these same nappe complexes, in dated sequences in (foreland) basins flanking the orogen, The period of forced cooling may be explained by tectonic unroofing by extensional tectonics, Cooling would have been by loss of insulation due to removal of overlying rock complexes and by superposition upon cooler rocks. The period of extensional tectonics and very fast cooling was produced by fast regional rock uplift triggered by detachment, shortly before 22 Ma, of subducted Mesozoic Tethys lithosphere representing the NW-dipping Betic-Rif subduction zone system which would represent the backbone of Betic-Rif orogeny. The Tethys realm comprised continental areas; opening of the North Atlantic and eastward drift of Iberia/Europe may have induced failure and initiated subduction in the weakest places, among which the Betic-Rif suture. Alpine orogeny in the western Mediterranean would thus mainly be conditioned by eastward drift of Iberia/Europe relative to North America, rather than by N-S convergence between Africa and Iberia/Europe, Plate kinematic reconstructions for the North Atlantic realm suggest that N-S-directed Africa-Iberia convergence was only minor and resulted in Top-northward structures. The present E-W grain of the Betic belt was initiated by the N-S convergence and emphasized during late-stage morphogenesis. Post-orogenic Neogene volcanics in the Betic-Alboran region are concentrated above the sinking lithospheric slab, which position is outlined by recent delay-time seismic tomography. The volcanics are suggested to have been formed from magmas generated in the overlying Betic lithosphere by anatexis in a HT regime caused by uplift of isotherms (decompression melting) and diapiric inflow of hot sub-lithospheric mantle in the widening gap above the sinking slab. A large body of multidisciplinary data suggest regional cooling rates of c. 500 degrees C/m.y. for high-grade metamorphic nappe complexes within the Alpine belt of the Betic Cordilleras within the period 22-17 Ma (Early Miocene, latest Aquitanian-Burdigalian), followed by much slower cooling in the period 19-6 Ma, down to c. 3 degrees C/m.y. from 16 to 6 Ma. The constraining thermochronometric information covers a temperature range of c. 700 degrees C to 25 degrees C and is from: (a) isotopic thermochronometers (muscovite- and biotite-WR Rb-Sr, muscovite and biotite 40Ar/39Ar, biotite K-Ar, and WR Rb-Sr); (b) apatite and zircon fission track studies; (c) paleontologic dates of foraminifera and nannoplankton from nappe-sealing sedimentary rocks; and (d) provenance studies, appearance of elastic material derived from these same nappe complexes, in dated sequences in (foreland) basins flanking the orogen, The period of forced cooling may be explained by tectonic unroofing by extensional tectonics, Cooling would have been by loss of insulation due to removal of overlying rock complexes and by superposition upon cooler rocks. The period of extensional tectonics and very fast cooling was produced by fast regional rock uplift triggered by detachment, shortly before 22 Ma, of subducted Mesozoic Tethys lithosphere representing the NW-dipping Betic-Rif subduction zone system which would represent the backbone of Betic-Rif orogeny. The Tethys realm comprised continental areas; opening of the North Atlantic and eastward drift of Iberia/Europe may have induced failure and initiated subduction in the weakest places, among which the Betic-Rif suture. Alpine orogeny in the western Mediterranean would thus mainly be conditioned by eastward drift of Iberia/Europe relative to North America, rather than by N-S convergence between Africa and Iberia/Europe, Plate kinematic reconstructions for the North Atlantic realm suggest that N-S-directed Africa-Iberia convergence was only minor and resulted in Top-northward structures. The present E-W grain of the Betic belt was initiated by the N-S convergence and emphasized during late-stage morphogenesis. Post-orogenic Neogene volcanics in the Betic-Alboran region are concentrated above the sinking lithospheric slab, which position is outlined by recent delay-time seismic tomography. The volcanics are suggested to have been formed from magmas generated in the overlying Betic lithosphere by anatexis in a HT regime caused by uplift of isotherms (decompression melting) and diapiric inflow of hot sub-lithospheric mantle in the widening gap above the sinking slab.
