This award supports the study of diatom and chrysophyte cyst assemblages in sediment cores recently collected from lakes in the Dry Valleys of Antarctica to understand local and global climate cycles over the past two million years. Diatoms are powerful paleoenvironmental indicators because of their ubiquity, preservation, and the environmentally restricted occurrences of different species. As many as one thousand samples will be analyzed to determine lake history with respect to water level, light penetration, and nutrient cycling. These cores represent the first non-glacial stratigraphic record from Antarctica that spans several full glacial cycles, and they may offer a nearly continuous record of environmental change from the late Pleistocene to present day. This record will permit correlation with regional paleoclimate records, such as those from Lake Vostok and deep-sea sediments. This work represents integrated, multidisciplinary research touching on geology, biology, glaciology, and climatology. In terms of broader impacts, it will improve society's understanding of global climate change from the perspective of a unique, terrestrial record that covers key recent periods. It also supports the education of postdoctoral and undergraduate students.
