Mesozoic and Cenozoic exhumation history of the SW Iberian Variscides inferred from low-temperature thermochronology

摘要: Abstract The post-Paleozoic tectonothermal evolution of the SW Iberian Variscides is poorly known mainly due to scarce low-temperature geochronological data available. We have obtained new apatite fission-tracks and (U–Th)/He ages constrain Mesozoic Cenozoic tectonic this portion Massif located just north Betic-Rif Alpine orogen. nine fission-track on samples from Variscan pre-Variscan granitoids. These range 174.4 (± 10.8) 54.1 (± 4.9) Ma, with mean track lengths between 10.3 13.9 μm. also performed 5 datings some same samples, obtaining 74.6 (± 1.6) 18.5 (± 1.4) Ma. Time–temperature path modeling these leads us envisage four tectonically controlled exhumation episodes in Variscides. Three occurred times (Middle Triassic Early Jurassic, Cretaceous, Late Cretaceous) at rates ≈ 1.1 2.5 °C Ma− 1, separated by periods almost no cooling. relate cooling events formation important marginal reliefs during rifting opening central northern Atlantic realm. fourth episode ≈ 3.2 3.6 °C Ma− 1, being only recorded next faults topographic escarpments. cooled below 80 °C ≈ 20 Ma 3–13 °C Ma− 1 roughly N–S oriented compressional stresses affecting whole plate, which, particular case Iberia, reactivated previous Paleozoic thrusts.