Abstract:

Exposure ages of bedrock samples taken from two nunataks in the Grove Mountains (GMs), interior East Antarctica, are studied by dating in situ produced cosmogenic 10Be and 26Al. The results indicate that the minimum exposure time of the five samples are all about 2Ma, much older than that of Last Glacial Maximum. This as well as the field observations indicates that the thickness of the interior East Antarctic Ice Sheet (EAIS) had reduced more than 200m since early to middle Pliocene. From then on, even in the period of the Last Glacial Maximum (LGM), the elevation of the interior EAIS is never higher than that of early to middle Pliocene