Apatite fission track and zircon (U-Th)/He dataset in the eastern Basque-Cantabrian Zone - western Pyrenees

Abstract

Low-temperature thermochronology studies have increased our knowledge of the orogenic processes along the Pyrenean-Cantabrian mountain belt by placing time constraints on the exhumation history of its rocks. However, a significant gap of data existed between the Pyrenees and the Cantabrian Mountains, hampering a comprehensive view of the tectonothermal evolution along the belt. Thus, we present a new apatite fission-track (AFT) and zircon (U-Th)/He (ZHe) dataset for the eastern Basque-Cantabrian zone and western Pyrenees. AFT central ages cluster in the Eocene-Oligocene. According to their ZHe age-eU correlations, samples can be separated into two groups: group 1 depicts clustered ZHe ages-eU concentrations (Cinco Villas Massif) and group 2 depicts dispersed ZHe ages-eU concentration (Alduides Massif and a Paleozoic rock pinned along the Leiza thrust sheet). A sample from the Oroz-Betelu Massif shows an intermediate behavior. Our results agree with previous data in the Pyrenean-Cantabrian mountain belt, supporting a Cenozoic cooling of the hinterlands of this part of the belt.