Neoproterozoic Earth History
The most important element of any story is time. The geological record contains a time series of events; reconstructing their order is essential for disentangling causes and effects. One of the most provocative stories recently extracted from the geological record comes from Neoproterozoic strata that host sedimentological and paleomagnetic evidence of sea-ice at equatorial latitudes. These data inspired the Snowball Earth hypothesis, which posits that during the Neoproterozoic, a runaway ice-albedo event resulted in global glaciation. Intriguingly, a major diversification of eukaryotic crown groups including the origin of animals is roughly coeval with these glaciations. This apparent coincidence gives rise to questions central to our origins: How extreme were these glaciations? Why did our climatic regulation system fail? Did global glaciation trigger the diversification of life? Did the diversification of life initiate climate catastrophe? To address these questions we first have to build accurate records of what actually happened and how these events unfolded.