Timing of eocene-miocene thrust activity in the western axial zone and chaînons béarnais (west-central Pyrenees) revealed by multi-method thermochronology
We present new apatite (U-Th)/He (AHe), apatite fission track (AFT) and zircon (U-Th)/He (ZHe) data to unravel the timing of exhumation and thrusting in the western Axial Zone of the Pyrenees and the adjacent North Pyrenean Zone (Chaînons Béarnais). In the north, ZHe data yield cooling signals betwe...
| Autores: | , , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2016 |
| País: | España |
| Institución: | Universitat Autònoma de Barcelona |
| Repositorio: | Dipòsit Digital de Documents de la UAB |
| Idioma: | inglés |
| OAI Identifier: | oai:ddd.uab.cat:168408 |
| Acceso en línea: | https://ddd.uab.cat/record/168408 https://dx.doi.org/urn:doi:10.1016/j.crte.2016.01.001 |
| Access Level: | acceso abierto |
| Palabra clave: | Thermochronology Apatite fission tracks Apatite and zircon (U-Th)/He Thrusting Pyrenees |
| Sumario: | We present new apatite (U-Th)/He (AHe), apatite fission track (AFT) and zircon (U-Th)/He (ZHe) data to unravel the timing of exhumation and thrusting in the western Axial Zone of the Pyrenees and the adjacent North Pyrenean Zone (Chaînons Béarnais). In the north, ZHe data yield cooling signals between 26-50 Ma in the Chaînons Béarnais, consistent with the onset of thrust-related cooling in the neighboring Mauléon basin modeled by previous authors. Non-reset Triassic ages are found in the footwall of the North Pyrenean Frontal thrust (Aquitaine basin). To the south, similar ZHe ages in both the hangingwall and footwall of the Lakora thrust record late Eocene to Oligocene cooling that we attribute to activity of the Gavarnie thrust. Thermal modeling of samples from the Lakora thrust hangingwall indicate cooling from early Eocene times, recording activity of the Lakora thrust. Paleozoic detrital samples from the westernmost Axial Zone and from the Eaux-Chaudes and Balaitous-Panticosa granitic plutons yield signals of AFT between 20-30 Ma and ZHe between 20-25 Ma. Modeling indicate fast cooling during this time that we attribute to motion of the Guarga thrust. AHe data from these Axial Zone plutons, combined with modeling, show a post-tectonic signal (8-9 Ma) that indicates renewed erosion after a period without major cooling and exhumation between 20 to 10 Ma. |
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