Paleothermometry in Oceanic Sediments to Determine Abrupt Climate Change Mechanisms

Paleoclimate records with sufficient length and temporal resolution to study the occurrence and causal mechanisms of abrupt climate change are exceedingly rare. Rapidly deposited ocean sediments provide the best archive for studying these events through geologic time, but such sites in the open ocean are limited to sediment drift deposits such as the Bermuda Rise in the northwest Atlantic. Using multiple climate proxies in a single core is becoming more common in high-resolution paleoclimate investigations, but a major potential concern for this approach arises from the possibility that the fine fraction of sediment, and the climate proxies within it, may represent conditions far from the deposition site. Here we propose and test the hypothesis that hydrogen isotope ratios of alkenones, a class of lipids from phytoplankton, may provide insight into the source of fine-grained sediment