Résumé
The fossil rift in the North Pyrenean Zone, which underwent high temperature–low pressure metamorphism and alkaline magmatism during Early Cretaceous hyperextension, was studied to explore the geothermal regime at the time of rifting. In this work, we used Raman lab analysis to shed light on the distribution of geothermal gradients across the inverted hyperextended Mauléon rift basin. Data from a set of 155 samples from densely spaced outcrops and boreholes, has been analyzed using Raman spectroscopy of carbonaceous material.