A review of the Milankovitch climatic beat: template for Plio–Pleistocene sea-level changes and sequence stratigraphy

Abstract

The Milankovitch theory of climate change predicts that global ice volume, and hence sea-level changes, were controlled by long-term quasi-periodic variations in the earth's orbital parameters (obliquity, precession and eccentricity). δ 18O records from deep-sea cores are a proxy for sea-level changes and have an orbitally tuned chronology covering the last 5 Ma. The sea-level signal in δ 18O data from east equatorial Pacific core V19-30 is well calibrated with sea-level data from coral terraces on Huon Peninsula, New Guinea, over the last 140 ka, and with less certainty back to 340 ka. Over the last 140 ka, the sea-level contribution to benthic glacial–interglacial isotopic variation is about 1.2–1.3‰ or 0.011‰ m −1, and for core V19-30 the glacial-age temperature contribution from deep ocean cooling of 1.7°C is 0.4‰. Independent constraints on Late Pliocene sea-level changes interpreted from shallow marine continental margin records indicate that the sea-level δ 18O calibration may not have been the same over the last 2.6 Ma, and the temperature correction is unlikely to have been the same in all glacial periods and all ocean settings. Nevertheless, the astronomically tuned isotopic records from deep-sea cores provide an accurate chronology and approximate the magnitudes of sea-level changes over the last 2.6 Ma, against which the facies architecture of stratigraphic sequences can be analysed and the concepts of sequence stratigraphy properly evaluated.