This research used samples and 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 Chinese National Science Foundation (number 49972047) and the Ministry of Land and Resources, China (number 200011000001). The authors would like to thank Professor Wang Pinxian and the Shipboard Scientific Party of ODP Leg 184 for collecting interstitial water and headspace gas samples. The paper also benefited from reviews by Dr. Peter Blum and Dr. S. Morad.