I thank the Joint Oceanographic Institutions, Inc. and the Ocean Drilling Program for enabling my participation on Leg 149. The scientific party and technical staff for Leg 149 provided valuable assistance and insights into this work. I wish to thank Drs. Randy Enkin and Stuart Gilder for providing valuable comments. I am also grateful to Professor Jose Honnorez for his thoughtful review and helpful comments. Special thanks go to Professor Rob Coe, who encouraged me to participate in ODP research and provided guidance during the study. Financial support for various part of this research was provided by a grant from the U.S. Science Advisory Committee and NSF grant EAR 443226-21777. This is also Institute of Tectonics of University of California at Santa Cruz Contribution no. 269.