Tectono-thermal history of an exhumed thrust-sheet-top basin: an example from the south Pyrenean thrust belt

摘要: This paper presents a new balanced structural cross-section of the Jaca thrust-sheet-top basin southern Pyrenees combined with paleo-thermometry and apatite fission track (AFT) thermochronology data. The cross-section, based on field data interpretation industrial seismic reflection profiles, allows refinement previous interpretations south-directed thrust system, involving identification faults, kinematic relationships between basement cover thrusts from middle Eocene to early Miocene. AFT analysis shows southward decrease in level resetting, totally reset Paleozoic rocks lower turbidites (indicative heating Tmax > ~120 °C), partially no/very weak resetting upper Eocene-lower Oligocene molasse (Tmax < ~60 °C). results indicate late Oligocene-early Miocene cooling event throughout Axial Zone Basin. Paleo-maximum temperatures determined by vitrinite reflectance measurements Raman spectroscopy carbonaceous material reach up ~240 °C at base turbidite succession. Inverse modelling QTQt software for key samples show compatibility vitrinite-derived Tmax most samples. However, they also suggest that highest lowermost correspond thermal anomaly rather than burial heating, possibly due fluid circulation during activity. From these results, we propose sequential restoration south Pyrenean system propagation related evolution.