New sedimentary records from contourite drifts on the West Antarctic continental margin; reconstruction of palaeoenvironmental changes during the late Quaternary by combining an integrated chronostratigraphic approach with multi-proxy investigations

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Author(s): Hillenbrand, Claus Dieter; Crowhurst, Simon; Channell, James E. T.; Williams, Maricel; Hodell, David A.; Xuan, Chuang; Allen, Claire S.; Ehrmann, Werner U.; Graham, Alastair G. C.; Larter, Robert D.
Author Affiliation(s): Primary:
British Antarctic Survey, Cambridge, United Kingdom
University of Cambridge, United Kingdom
University of Florida, United States
University of Southampton, United Kingdom
University of Leipzig, Germany
University of Exeter, Exeter, United Kingdom
Volume Title: AGU 2016 fall meeting
Source: American Geophysical Union Fall Meeting, Vol.2016; American Geophysical Union 2016 fall meeting, San Francisco, CA, Dec. 12-16, 2016. Publisher: American Geophysical Union, Washington, DC, United States
Note: In English
Summary: Giant sediment drifts located on the continental rise west of the Antarctic Peninsula and in the Bellingshausen Sea contain a high-resolution archive of ice sheet history in West Antarctica and of palaeoceanographic changes in the Southern Ocean. However, previous studies on sediment cores recovered from these contourite drifts, including Ocean Drilling Program (ODP) Leg 178, were compromised by lack of reliable high-resolution chronological control. This shortcoming is mainly caused by the very low abundance of calcareous microfossils in the sediments that are required for applying radiocarbon dating and stable oxygen isotope (δ18O) stratigraphy. Moreover, sediments assumed to have been deposited during glacial periods consist almost entirely of terrigenous detritus, i.e. they lack even siliceous microfossils that could be utilised for biostratigraphic purposes. International Ocean Discovery Program (IODP) proposal 732-Full2 aims to obtain continuous, high-resolution records from sites on the West Antarctic sediment drifts and to develop reliable age models for them. The strategy for achieving the second objective is to use a range of chronostratigraphic techniques, including relative geomagnetic palaeointensity (RPI) and δ18O stratigraphy, on sedimentary sequences recovered from the shallowest parts of the drift crests, where the preservation of calcareous microfossils is expected be higher than in deeper water. Here we present preliminary results of multi-proxy investigations on new piston and box cores recovered from the proposed drill sites during site survey investigation cruise JR298 of the RRS James Clark Ross in 2015. Apart from the integrated chronological approach, the new cores augment previous assessments of palaeoenvironmental change on the West Antarctic continental margin during glacial-interglacial cycles of the Late Quaternary.
Year of Publication: 2016
Research Program: IODP2 International Ocean Discovery Program
ODP Ocean Drilling Program
Key Words: 07 Marine Geology and Oceanography; Antarctica; International Ocean Discovery Program; Leg 178; Ocean Drilling Program; Southern Ocean; West Antarctica
Coordinates: S673400 S634800 W0640000 W0783000
Record ID: 2017077325
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