Technical note: Late Pliocene age control and composite depths at ODP Site 982, revisited

Abstract

Ocean Drilling Program (ODP) Site 982 provided a key sediment section at Rockall Plateau for reconstructing northeast Atlantic paleoceanography and monitoring benthic &delta;¹⁸O stratigraphy over the late Pliocene to Quaternary onset of major Northern Hemisphere glaciation. A renewed hole-specific inspection of magnetostratigraphic reversals and the addition of epibenthic &delta;¹⁸O records for short Pliocene sections in holes 982A, B, and C, crossing core breaks in the &delta;¹⁸O record published for Hole 982B, now imply a major revision of composite core depths. After tuning to the orbitally tuned reference record LR04, the new composite &delta;¹⁸O record results in a hiatus, where the Kaena magnetic subchron might have been lost, and in a significant age reduction for all proxy records by 130 to 20 ky over the time span 3.2–2.7 million years ago (Ma). Our study demonstrates the general significance of reliable composite-depth scales and &delta;¹⁸O stratigraphies in ODP sediment records for generating ocean-wide correlations in paleoceanography. The new concept of age control makes the late Pliocene trends in SST (sea surface temperature) and atmospheric <i>p</i>CO₂ at Site 982 more consistent with various paleoclimate trends published from elsewhere in the North Atlantic.