This research used samples and/or data provided by the Ocean Drilling Program (ODP). ODP is sponsored by the U.S. National Science Foundation (NSF) and participating countries under management of Joint Oceanographic Institutions (JOI), Inc. Funding for this research was provided by grants from the National Natural Science Foundation of China, Chinese Academy of Sciences, and Australian Research Council. Xin Su supplied unpublished nannofossil data. Oxygen isotopic data and calculation of isotopic events were provided by Quanhong Zhao. William Chaisson and Peter Blum reviewed the manuscript and offered valuable suggestions.