Surface exposure ages imply multiple low-amplitude Pleistocene variations in East Antarctic Ice Sheet, Ricker Hills, Victoria Land

• Published in: Antarctic Science
• Main Authors: Stefan Strasky, Luigia Di Nicola, Carlo Baroni, Heinrich Baur, Peter W. Kubik, C. Schluechter, Rainer Wieler, SALVATORE, Maria Cristina
• Other Authors: Stefan, Strasky, Luigia Di, Nicola, Carlo, Baroni, Salvatore, Maria Cristina, Heinrich, Baur, Peter W., Kubik, C., Schluechter, Rainer, Wieler
• Format: Article in Journal/Newspaper
• Language: English
• Published: -Cambridge University Press / New York:40 West 20th Street:New York, NY 10011:[phone], [phone], EMAIL: [e-mail], INTERNET: http://www.journals.cambridge.org, Fax: [phone] -Oxford: Blackwell Scientific Publications. 2009
• Subjects: cosmogenic nuclide; erosion rate; glacial drift; landscape evolution; surface exposure dating; Antarctic; East Antarctic Ice Sheet; Ricker Hills; Victoria Land; Antarc*; Ice Sheet
• Online Access: http://hdl.handle.net/11573/37666; https://doi.org/10.1017/s0954102008001478; http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=000263389100005&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=0c7ff228ccbaaa74236f48834a34396a; http://www.scopus.com/inward/record.url?eid=2-s2.0-67649226448&partnerID=65&md5=a8d7288bdc46887bd5f9bd4f69d6fbaf

One of the major issues in (palaeo-) climatology is the response of Antarctic ice sheets to global climate changes. Antarctic ice volume has varied in the past but the extent and timing of these fluctuations are not well known. In this study, we address the question of amplitude and timing of past Antarctic ice level changes by surface exposure dating using in situ produced cosmogenic nuclides (10Be and 21Ne). The study area lies in the Ricker Hills, a nunatak at the boundary of the East Antarctic Ice Sheet in southern Victoria Land. By determining exposure ages of erratic boulders from glacial drifts we directly date East Antarctic Ice Sheet variations. Erosion-corrected neon and beryllium exposure ages indicate that a major ice advance reaching elevations of about 500 m above present ice levels occurred between 1.125 and 1.375 million years before present. Subsequent ice fluctuations were of lesser extent but timing is difficult as all erratic boulders from related deposits show complex exposure histories. Sample-specific erosion rates were on the order of 20–45 cm Ma-1 for a quartzite and 10–65 cm Ma-1 for a sandstone boulder and imply that the modern cold, arid climate has persisted since at least the early Pleistocene.