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Titel |
Records of glacial-interglacial variability during the Pliocene: IODP Expedition 318 - Site U1361 |
VerfasserIn |
J. J. González, C. Escutia, F. J. Espejo, T. Williams, R. M. McKay, S. Passhier, T. van de Flierdt, L. Tauxe, H. Brinkhuis |
Konferenz |
EGU General Assembly 2012
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Medientyp |
Artikel
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Sprache |
Englisch
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Digitales Dokument |
PDF |
Erschienen |
In: GRA - Volume 14 (2012) |
Datensatznummer |
250070173
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Zusammenfassung |
One of the aims of IODP Expedition 318 drilling on the East Antarctic Wilkes Land margin
was to obtain the record of Antarctic climate and cryosphere variability during the past warm
climates of the early-middle Pliocene.
A complete Pliocene section was recovered from Site U1361, located on the continental
rise eastern levee of the Jussieu Channel. We present the results from a continous
high-resolution geochemical study (X-Ray Fluorescence (XRF) scanner and discrete XRF
analysis) conducted on sediments from Site U1361. These records are compared with
shipboard physical properties data measured on the core, clay mineralogy analyses and
with a post-cruise revised sedimentary facies model. Age constrains for the studied
sediments are provided by the age-depth model constructed shipboard and refined
post-cruise, which indicated the studies sediments to be comprised between 5.18 and 2.46
Ma.
The downcore variations of these multiple proxies is interpreted to result from changes
in primary biogenic productivity, terrigenous supply, and sedimentary processes
that allow us to reconstruct changes in paleoceanographic and paleoenvironmental
conditions associated with glacial–interglacial cyclicity. In this sense it is remarkable
the Ba/Al and Ca variations, associated to the diatomaceous-rich silty-clay facies,
suggesting high-productivity during interglacial periods at our site. In addition
to the glacial/interglacial cyclic variability, we also discuss a marked change in
the compositional and physical properties variability patterns within the section
that we interpret to correspond with the start of the Pliocene cooling trend in this
margin.
This contribution results from work funded by: the Integrated Ocean Drilling Program,
CTM2009-08467-E (Spanish Ministry of Science and Education and FEDER funds); and the
Spanish Ministry of Science and Innovation project CAGES (CTM2011-24079). |
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