Thursday, 30 August 2007 - 10:50 AM
4.A.A-3
Records of past ice sheet fluctuation in interior East Antarctica
Xiaohan Liu, Deputy director, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, 18 Shuangqing Road, Haidian District, Beijing, POBox 2871, Beijing, Beijing, 100085, China
Summary: Land-based multi-disciplinary study of the past ice surface fluctuation in the Grove Mountains , interior East Antarctica support a dynamic evolution. Based on geomorphic evidence, ages of soil formation, lithologic analyses of sedimentary boulders, spore pollen assemblages, coupled with in-situ cosmogenic nuclide exposure ages, we suggest that:
1. The margin of the EAIS once lay beyond of the GMs region, some450 km south from its present coastal position, before the Late Pliocene. This retreat testifies to the Middle Pliocene warmth.
2. The elevation of ice surface in the GMs region subsequently rose to more than at least 450m higher than today, before at least 2.3 Ma.
3. The ice surface then progressively descended from 2.3 Ma to 1.6 Ma, and it suffered small turbulent fluctuation since the Early Pleistocene. However, the highest level it reached never exceeded ~100 m above recent level.
1. The margin of the EAIS once lay beyond of the GMs region, some
2. The elevation of ice surface in the GMs region subsequently rose to more than at least 450m higher than today, before at least 2.3 Ma.
3. The ice surface then progressively descended from 2.3 Ma to 1.6 Ma, and it suffered small turbulent fluctuation since the Early Pleistocene. However, the highest level it reached never exceeded ~