Abstract We present results of a multi-proxy study on marine sediment core JR179-PC466 recovered from the crest of a sediment drift off the West Antarctic Peninsula at approximately 2300 m water depth. The 10.45 m-long core consists dominantly of glaciomarine terrigenous sediments, with only traces of calcium carbonate (<1 wt%). Despite the very low abundance of calcareous foraminifera, planktonic shell numbers are sufficient for stable isotope analyses in two-thirds of the samples studied. The core chronology is based on oxygen isotope stratigraphy and correlation of its relative palaeomagnetic intensity (RPI) with a stacked reference curve. According to the age model, core PC466 spans the last 75 ka, with average sedimentation rates of between about 4 and 25 cm ka −1 . Planktonic foraminifera abundances fluctuate between 0 and 30 individuals per gram throughout the core, with minima observed during Marine Isotope Stage (MIS) 2 (14–29 ka before present, BP) and MIS4 (57–71 ka BP). Planktonic foraminifera are present in the Holocene but more abundant in sediments deposited during MIS3 (29–57 ka BP), owing to less dilution by terrigenous detritus and/or better carbonate preservation. During MIS3, foraminifera maxima correlate with Antarctic warming events as recorded in the δ 18 O signal of the EPICA Dronning Maud Land (EDML) ice core. They indicate higher planktonic foraminifera production and better carbonate preservation west of the Antarctic Peninsula during that time. The abundance of ice-rafted detritus (IRD) in core PC466 increased during the last deglaciation between about 19 and 11 ka BP, when numerous icebergs drifted across the core site, thereby releasing IRD. During this time, sea-level rise destabilized the Antarctic Peninsula (APIS) and West Antarctic (WAIS) ice sheets that had advanced onto the shelf during the sea-level low-stand of the Last Glacial Maximum (LGM; c . 19–23 ka BP). Overall, our results demonstrate that it is possible to establish an age model and reconstruct palaeoceanographical and climatic changes at high temporal resolution from sedimentary sequences recovered at 2300 m water depth from a West Antarctic drift.

Abstract Comparison of oceanic anomaly block models in the M0-M29 interval from the Japanese, Phoenix, Hawaiian and Keathley lineations indicates that the Hawaiian block model represents the closest approximation to a constant spreading rate record. The new Hawaiian block model differs slightly from that of Larson and Hilde (1975). Currently popular numerical age estimates for polarity chrons, base CM0 (121 Ma), CM16-CM15 (137 Ma) and top CM25 (154 Ma), are consistent with constant spreading rate in the new Hawaiian block model but inconsistent with constant spreading in the Larson and Hilde (1975) block model. A new time scale (CENT94) is based on the above ages and constant spreading in the new Hawaiian block model. Land section magnetostratigraphy, mainly from Italy and Spain, has provided direct correlations of polarity chrons to stage boundaries through ammonite biozones, and indirect correlation through nannofossil and calpionellid biozonations: Barremian-Aptian (base of CM0), Hauterivian-Barremian (upper part of CM4), Valanginian-Hauterivian (base of CM1 In), Berriasian-Valanginian (CM15n), Tithonian-Berriasian (base of CM18), Kimmeridgian-Tithonian (CM22A) and Oxfordian-Kimmeridgian (top CM25). These correlations yield the following stage boundary ages using CENT94: Barremian-Aptian (121 Ma), Hauterivian-Barremian (126 Ma), Valanginian-Hauterivian (131.5 Ma), Berriasian-Valanginian (135.8 Ma), Tithonian-Berriasian (141.6 Ma), Kimmeridgian-Tithonian (150 Ma), and Oxfordian-Kimmeridgian (154 Ma).