PREVIOUS DRILLING
Nearly 30 years ago, Deep Sea Drilling Project (DSDP) rotary drilling and coring of the central Pacific equatorial mound of sediments (e.g., DSDP Legs 5, 8, 9, and 16) established the general pattern of equatorial sediment accumulation and plate migration through the Neogene and late Paleogene (e.g., van Andel et al. 1975; Leinen, 1979). However, the rotary coring technology available to these very early legs could not provide undisturbed sections or complete recovery and was utterly defeated by middle Eocene chert layers encountered in some of the more deeply buried sections. Thus, even the broad outlines of equatorial sediment accumulation in the middle Eocene and older sediments remain poorly defined. The complete recovery of undisturbed and largely unaltered sections in a transect of the Pacific Paleogene sediments has yet to be accomplished.