Articles | Volume 4, issue 1
https://doi.org/10.5194/gchron-4-191-2022
https://doi.org/10.5194/gchron-4-191-2022
Research article
 | 
07 Apr 2022
Research article |  | 07 Apr 2022

Cosmogenic ages indicate no MIS 2 refugia in the Alexander Archipelago, Alaska

Caleb K. Walcott, Jason P. Briner, James F. Baichtal, Alia J. Lesnek, and Joseph M. Licciardi

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Cited articles

Addison, J. A., Beget, J. E., Ager, T. A., and Finney, B. P.: Marine tephrochronology of the Mt. Edgecumbe volcanic field, southeast Alaska, USA, Quaternary Res., 73, 277–292, https://doi.org/10.1016/j.yqres.2009.10.007, 2010. 
Ager, T. A.: Late Quaternary vegetation development following deglaciation of northwestern Alexander Archipelago, Alaska, Front. Earth Sci., 7, 104, https://doi.org/10.3389/feart.2019.00104, 2019. 
Baichtal, J. F., Lesnek, A. J., Carlson, R. J., Schmuck, N., Smith, J. L., Landwehr, D. J., and Briner, J. P.: Late Pleistocene and Early Holocene Sea level History Glacial Retreat Interpreted from Shell-bearing Marine Deposits of Southeastern Alaska, Geosphere, 17, 1590–1615, https://doi.org/10.1130/GES02359.1, 2021. 
Balco, G.: Production rate calculations for cosmic-ray-muon-produced 10Be and 26Al benchmarked against geological calibration data, Quat. Geochronol., 39, 150–173, 2017. 
Balco, G.: Technical note: A prototype transparent-middle-layer data management and analysis infrastructure for cosmogenic-nuclide exposure dating, Geochronology, 2, 169–175, https://doi.org/10.5194/gchron-2-169-2020, 2020. 
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Short summary
We present a record of ice retreat from the northern Alexander Archipelago, Alaska. During the last ice age (~ 26 000–19 000 years ago), these islands were covered by the Cordilleran Ice Sheet. We tested whether islands were ice-free during the last ice age for human migrants moving from Asia to the Americas. We found that these islands became ice-free between ~ 15 100 years ago and ~ 16 000 years ago, and thus these islands were not suitable for human habitation during the last ice age.