Matthew T. Hurtgen, Penn State Astrobiology Research Center and Department of Geosciences, takes a look at the first results of a new class of measurements with important implications that test the Snowball Earth hypothesis. Hurtgen and colleagues' preliminary results appear consistent with predictions of the hypothesis.
Daniel P. Schrag, also from the Department of Earth and Planetary Sciences at Harvard, will propose an innovative, counterintuitive mechanism for triggering Snowball events. Evidence indicates that there was increased methane prior to glaciation. If Snowball events depended on this mechanism, a rise in atmospheric oxygen could explain why the rise of multicellular animals coincided with the end of Snowball events.
James C.G. Walker, Geological Sciences Department at the University of Michigan, will take a look at the strange weather patterns during Snowball Earth which resulted from the arid atmosphere and the solid ocean.
Bruce Runnegar, Professor of Paleontology at UCLA, will take a look at "hard" and "soft" versions of scenarios in the Snowball Earth hypothesis, emphasizing the latter in relation to the global biosphere.
Martin J. Kennedy from the University of California, Riverside, will propose that methane released from permafrost due to warming associated with post-glacial sea-level rise may explain the isotopic signature of 'cap' carbonates. Unusual sedimentary structures will be cited in support of the idea, but their interpretation will be debated. (Kennedy published an article on this topic in the May issue of GEOLOGY.)
A Snowball Earth workshop, promising lively discussion and debate, immediately follows this session.
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Contact: Ann Cairns
acairns@geosociety.org
303-447-2020 x 1156
Geological Society of America
24-May-2001