1 Popular Summary of Scientific Work Achieved

In the last 15 years, deep cores through the Antarctic ice sheet have provided a wealth of high resolution climate data, which have been invaluable for testing both regional and global climate models. Although ice core data only cover the last 500,000 years of earth history, the possibility of obtaining much older climate data is now recognized in a few select areas where ancient glacial ice has stagnated and lies buried beneath rock debris. Beacon Valley contains the best known relict ice, which if glacial has been dated by a volcanic ash layer as more than 8 million years old. This age remains controversial, but other occurrences of relict ice have recently been discovered in Pearse, Columnar, and Victoria Valleys and appear to be analogous to Beacon. The ongoing aim of this project is to understand the origin and paleoenvironmental significance of ice from these areas and place them in context with the Beacon Valley ice. Of particular value will be the independent dating of debris covering the ice. We will use a new method of beryllium-10 dating, which unlike exposure age methods, can extend back at least 20 million years.