Zircon single-grains (U-Th-Sm)/He ages (ZHe) from the Bielsa (BAZ), Néouvielle (NAZ) and Bordères-Louron (BLAZ) granite massifs, Pyrenees (France- Spain)

- method:

• Zircon grains from the 50‐ to 250‐μm fraction were isolated using conventional mineral separation techniques, including crushing, grinding, sieving, and water table concentration, standard heavy‐liquid density, and magnetic susceptibility separation techniques.  • Conventional bulk single‐grain ZHe analyses have been performed at the Centre de Recherches Pétrographiques et Géochimiques (CRPG, Nancy, France) following procedures described in Pik et al. (2003) and Godard et al. (2009) for 4He extraction and Tibari et al. (2016) for bulk parent U, Th, and Sm concentration measurements.  • Based on replicate analysis of the Fish Canyon Tuff age standard (mean age over the measurement period = 28.6 +/- 1.6 Ma) analytical uncertainties for ZHe ages are estimated at ~ 6% (1σ).  • ZHe ages are morphometrically corrected for alpha‐ejection (the ejection correction parameter FT) according to Ketcham et al. (2011). • Equivalent U concentration : [eU] = [U] + 0.235 x [Th] Godard, V., Pik, R., Lavé, J., Cattin, R., Tibari, B., de Sigoyer, J., et al. (2009). Late Cenozoic evolution of the central Longmen Shan, easternTibet: Insight from (U‐Th)/He thermochronometry. Tectonics, 28, TC5009. https://doi.org/10.1029/2008TC002407 Hourigan, J. K., Reiners, P. W., & Brandon, M. T. (2005). U‐Th zonation‐dependent alpha‐ejection in (U‐Th)/He chronometry. Geochimicaet Cosmochimica Acta, 69(13), 3349–3365. https://doi.org/10.1016/j.gca.2005.01.024 Ketcham, R. A., Gautheron, C., & Tassan‐Got, L. (2011). Accounting for long alpha‐particle stopping distances in (U–Th–Sm)/He geochronology:Refinement of the baseline case. Geochimica et Cosmochimica Acta, 75(24), 7779–7791. https://doi.org/10.1016/j.gca.2011.10.011 Pik, R., Marty, B., Carignan, J., & Lavé, J. (2003). Stability of the Upper Nile drainage network (Ethiopia) deduced from (U–Th)/He thermochronometry:Implications for uplift and erosion of the Afar plume dome. Earth and Planetary Science Letters, 215(1‐2), 73–88.https://doi.org/10.1016/S0012‐821X(03)00457‐6 Tibari, B., Vacherat, A., Stab, M., Pik, R., Yeghicheyan, D., & Hild, P. (2016). An alternative protocol for single zircon dissolution withapplication to (U‐Th‐Sm)/He thermochronometry. Geostandards and Geoanalytical Research https://doi.org/10.1111/j.1751‐908X.2016.00375.x, 40(3), 365–375.