This award supports a study to use biological indicators, namely fossil records of cryptoendolithic microbial colonization of Beacon sandstone and microorganisms in permafrost, to reconstruct paleoclimate history of the Late Plio-Pleistocene period in the McMurdo Dry Valleys. The work will attempt to address the stabilist versus the dynamicist view of the Antarctic ice sheet using past and present occurences of distributions of climatically sensitive living and fossilized biological indicators in the Dry Valleys region. Specifically, soil derived from Beacon Sandstone and permafrost cores will be analyzed for the occurence of living and fossilized microbial groups whose viability zones are already known or will be determined by mapping the distribution of present occurences. This information will be integrated with the distribution of characteristic exfoliation patterns (recent and fossil) caused by microbial activity to reconstruct relative age sequences. The sedimentology of the permafrost cores will be characterized and integrated with microbiological and chronostratigraphic data. Absolute chronologies will be provided (where appropriate) by carbon-14, thermoluminesence dating and analysis of cosmogenic radionuclides.
