 |
| Titel |
Marine paleoproductivity at warmer climate conditions during the Late Pliocene and Early Pleistocene in the Ross Sea |
| VerfasserIn |
D. Helling, G. Kühn, H. von Eynatten |
| Konferenz |
EGU General Assembly 2009
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250019469
|
|
|
|
|
|
| Zusammenfassung |
| The ice-uncovered Ross Sea, Antarctica, is a place with almost the highest bioproductivity
rates in the Southern Ocean. In the past melting and collapse of large ice shelves caused
highly variable conditions according to paleoproductivity in the McMurdo Sound (Ross Sea).
The ANDRILL (Antarctic Geological Drilling) MIS deep drilling project (McMurdo
Sound, NE Ross Ice Shelf, core AND-1B) drilled during austral summer 2006/2007 a
well-preserved, outstanding record of approximately 14 million years of paleoclimate
history. High-resolution geochemical data (XRF core scanning) and colour data
(line scanning and reflectance measurements) in addition to quantitative chemistry
data (e.g. opal, TOC and minor and major elements) and XRD on discrete samples
were achieved. Colour data and XRF-CS counts are correlated to sample data to
receive more and higher resolved information about the sediment composition. The
interpretation of rapid paleoclimatic changes in the Antarctic realm, especially
to understand the behaviour of the Ross Ice Shelf during the past million years,
is one target of our study. From the Late Pliocene transitions from diamictite to
diatomites are described which imply shifting from a retreating ice sheet to open marine
conditions. The diatomites represent time spans with high bioproductivity and reflect
warmer conditions at the Antarctic margin than today. The opal content increased to
~60-80% during 6 interglacials (151.70 – 224.45 mbsf). Within these interglacials, the
paleoproductivity show variations that seem to be forced by small-scale climate variations. |
|
|
|
|
|
|