1. Leg 199 Synthesis: Evolution of the Equatorial Pacific in the Early Cenozoic1

Mitchell Lyle2 and Paul A.Wilson3


Ocean Drilling Program Leg 199, the first paleoceanographic leg in 30 years to target the Paleogene equatorial Pacific, had three primary objectives. First, the drilling was designed to develop modern age models and cross-calibrate biostratigraphy, magnetostratigraphy, isotope stratigraphy, and physical stratigraphy of the equatorial Pacific in order to form a chronologic framework of events. Second, specific intervals were targeted to constrain important paleoceanographic change. Three boundaries were targeted in particular: the Paleocene/Eocene (P/E) boundary, Eocene/Oligocene (E/O) boundary, and the late Oligocene and Oligocene/Miocene (O/M) boundary. Third, comprehensive time series studies were carried out on long intervals of Paleogene core to understand the long-term evolution of the equatorial Pacific, including changes in productivity, marine chemistry, temperature, and ice volume. The scientific goals were achieved through a drilling transect that crosses the position of the 56-Ma Pacific equator with an additional drill site (Site 1218) located at the 40-Ma Pacific equator.

1Lyle, M., and Wilson, P.A., 2006. Leg 199 synthesis: Evolution of the equatorial Pacific in the early Cenozoic. In Wilson, P.A., Lyle, M., and Firth, J.V. (Eds.), Proc. ODP, Sci. Results, 199 [Online]. Available from World Wide Web: <http://www-odp.tamu.edu/publications/199_SR/synth/synth.htm>. [Cited YYYY-MM-DD]

2Center for Geophysical Investigation of the Shallow Subsurface, Boise State University, 1910 University Drive, Boise ID 83703 USA. Present address: Department of Oceanography, Texas A&M University, College Station TX 77843, USA. mlyle@cgiss.boisestate.edu

3National Oceanography Centre, Southampton School of Ocean and Earth Science, Southampton SO14 3ZH, UK.

Initial receipt: 22 February 2006
Acceptance: 4 September 2006
Web publication: 27 September 2006
Ms 199SR-201