East Pacific Rise Core PS75/059-2: Glacial-to-Deglacial Stratigraphy Revisited

Age control and paleoceanographic evidence of marine sediment records might be challenged if authors solely build their stratigraphy on visual correlation to apparently well-dated records from the same ocean basin, using, for example, highly resolved X-ray fluorescence-based element-count records and correlation tools such as AnalySeries. While per se perfectly reasonable, this approach bears the risk of missing stratigraphic gaps in the sedimentary record and thus might result in imprecise and/or flawed interpretations. Here we present a unique series of 14 planktic C-14 ages from a 7-cm section of East Pacific Rise core PS75/059-2. The ages suggest a 14-ky-long period of low-to-zero deposition during Last Glacial Maximum, mainly marked by continuous redistribution of winnowed foraminifers, probably the result of enhanced bottom currents, moreover, by some bioturbational mixing. On the basis of this data we demonstrate the impact of the hiatus on a South Pacific transect of apparent benthic ventilation ages (Delta Delta C-14 values) and their meaning for estimates of CO2 stored in Last Glacial Maximum Pacific deep waters.