HIGH-RESOLUTION AGE CONTROL FOR THE LATE PALEOZOIC ICE AGE SUCCESSIONS ACROSS SW AND SC GONDWANA ­­­­­­­­­­– IMPLICATIONS FOR CLIMATIC FORCING FOR THE END OF THE LPIA

Griffis, Neil; Mundil, Roland; Mundil, Roland; Montañez, Isabel P.; Montañez, Isabel P.; Linol, Bastien; Linol, Bastien; de Wit, Maarten J.; de Wit, Maarten J.; Isbell, John L.; Isbell, John L.; Fedorchuk, Nick; Fedorchuk, Nick; Keller, C. Brenhin; Keller, C. Brenhin; Iannuzzi, Roberto; Iannuzzi, Roberto; Vesely, Fernando; Vesely, Fernando; Mottin, Thammy; Mottin, Thammy; da Rosa, Eduardo L.M.; da Rosa, Eduardo L.M.; Richey, Jon D.; Richey, Jon D.; Yin, Qing-zhu; Yin, Qing-zhu

doi:10.1130/abs/2018AM-324163

Abstract The dispersed remnants of stellar nurseries, stellar associations, provide unparalleled samples of coeval stars critical for studies of stellar and planetary formation and evolution. The Carina Stellar Association is one of the closest stellar associations to Earth, and yet measurements of its age have varied from 13 to 45 Myr. We aim to update the age of Carina using the lithium depletion boundary (LDB) method. We obtain new measurements of the Li 6708 Å absorption feature in likely members using optical spectra from the Goodman High Throughput Spectrograph on SOAR and NRES on LCO. We detect the depletion boundary atM_K≃ 6.8 (M5). This age is consistent within uncertainties across six different models, including those that account for magnetic fields and spots. We also estimate the age through analysis of the group’s overall variability, and by comparing the association members’ color–magnitude diagram to stellar evolutionary models using a Gaussian Mixture Model, recovering ages consistent with the LDB. Combining these age measures we obtain an age for the Carina association of

41_{- 5}^{+ 3}

Myr. The resulting age agrees with the older end of previous age measurements and is consistent with the lithium depletion age for the neighboring Tucana-Horologium moving group.

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