Comment on Barrell et al. “Reconciling the onset of deglaciation in the Upper Rangitata valley, Southern Alps, New Zealand” (Quaternary Science Reviews 203 (2019), 141–150.)

Abstract

Recently, Barrell et al. (2019) published an article that responded to our article (Shulmeister et al., 2018a) on gradual evacuation of ice from the Upper Rangitata Valley, South Island, New Zealand, during the last glaciation. They base their contrasting interpretation of substantial and rapid ice-lowering of Rangitata glacier shortly after 18 ka on a revision of our 10Be cosmogenic radionuclide (CRN) chronology and by reference to published sources (e.g. Mabin, 1980, 1987). Their interpretation relies on glacial landform features extracted from a geomorphology map of the central Southern Alps by Barrell et al. (2011). Barrell et al. (2019) highlight that rapid ice recession of the Rangitata glacier is compatible to their results from Mackenzie Basin and Rakaia Valley (Putnam et al., 2013a, b). We highlight four points in response to Barrell et al. (2019). © 2019 Elsevier Ltd.