NOAA/WDS Paleoclimatology - Lisiecki and Raymo 2005 Global Pliocene-Pleistocene Benthic d18O Stack

STUDY NOTES: Lisiecki-Raymo 2004 (LR04) Global Pliocene-Pleistocene Benthic D18O Stack. The LR04 stack spans 5.3 Myr and was constructed by graphically aligning 57 globally distributed benthic d18O records. Its age model is orbitally tuned to June 21 insolation at 65N but is also constrained by the average sedimentation rates of the 57 sites. LAST UPDATES: 8/2005 (Change number of significant digits in LR04 stack); 7/2005 (final version, 0.64 permil correction for Cibicidoides added)
ABSTRACT SUPPLIED BY ORIGINATOR: We present a 5.3-Myr stack (the “LR04” stack) of benthic δ18O records from 57 globally distributed sites aligned by an automated graphic correlation algorithm. This is the first benthic δ18O stack composed of more than three records to extend beyond 850 ka, and we use its improved signal quality to identify 24 new marine isotope stages in the early Pliocene. We also present a new LR04 age model for the Pliocene-Pleistocene derived from tuning the δ18O stack to a simple ice model based on 21 June insolation at 65°N. Stacked sedimentation rates provide additional age model constraints to prevent overtuning. Despite a conservative tuning strategy, the LR04 benthic stack exhibits significant coherency with insolation in the obliquity band throughout the entire 5.3 Myr and in the precession band for more than half of the record. The LR04 stack contains significantly more variance in benthic δ18O than previously published stacks of the late Pleistocene as the result of higher-resolution records, a better alignment technique, and a greater percentage of records from the Atlantic. Finally, the relative phases of the stack's 41- and 23-kyr components suggest that the precession component of δ18O from 2.7–1.6 Ma is primarily a deep-water temperature signal and that the phase of δ18O precession response changed suddenly at 1.6 Ma.