干旱区生态环境知识资源中心

Be-10 and Al-26 data from sandstone boulders in three Neogene glacial deposits in the McMurdo Sound-Dry Valleys region of southern Victoria Land, Antarctica, indicate minimum exposure ages of similar to 3 Ma and maximum long-term erosion rates of similar to 5-12 cm/m.y., supporting the suggestion that polar desert conditions have persisted in the Dry Valleys since at least late Pliocene time. Variation of cosmogenic nuclide production rate with altitude also allows constraints on past uplift rates. Model calculations employing Be-10 data indicate little or no uplift in the Dry Valleys region in the past 3 m.y., precluding rapid (similar to 1 km/m.y.) late Pliocene uplift previously suggested for some parts of the Transantarctic Mountains.