Revised composite depth scales and integration of IODP Sites U1331–U1334 and ODP Sites 1218–1220

Abstract

To reconstruct the climate history of the equatorial Pacific, one major objective of the Pacific Equatorial Age Transect (PEAT) program is to compile a Cenozoic megasplice that integrates all available bio-, chemo-, and magnetostratigraphic data including key records from Ocean Drilling Program (ODP) Leg 199. In order to do so, extended postcruise refinements of the shipboard composite depth scales and composite records are required. Here, we present a revised depth scale of Integrated Ocean Drilling Program (IODP) Expedition 320 Sites U1331, U1332, U1333, and U1334 as well as Leg 199 Sites 1218, 1219, and 1220. The revised composite records were used to perform site-to-site correlation and integration of Leg 199 and Expedition 320 sites. Based on this decimeter-scale correlation, a high-resolution integrated paleomagnetic, calcareous nannofossil, and radiolarian stratigraphy for the equatorial Pacific is established that covers the time from 20 to 40 Ma. This sedimentary compendium from the equatorial Pacific will be the backbone for paleoceanographic reconstructions for the late Paleogene.