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| Titel |
Paleo-environment of cold-water coral initiation in the NE Atlantic:Implications from a deep-water carbonate mound drilling core |
| VerfasserIn |
J. Raddatz, A. Rüggeberg, W.-Chr. Dullo  , S. Margreht |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250021440
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| Zusammenfassung |
| The understanding of the paleo-environment during initiation and early development of
deep-water carbonate mounds in the NE Atlantic is still under debate. The Integrated Ocean
Drilling Program Expedition 307 sailed in 2005 to the Porcupine Seabight in order to
investigate for the first time sediments from the base of a giant carbonate mound (Challenger
Mound, 155 m). These results indicate that the initiation and start-up phase of this carbonate
mound coincides with the beginning of the Northern Hemisphere Glaciation (NHG) at around
2.6 Ma (Kano et al. 2007). Further carbonate mound development seems to be strongly
dependent on rapid changes in paleo-oceanographic and climatic conditions around the
Pliocene-Pleistocene boundary, especially characterized and caused by intermediate water
masses.
To characterise the paleo-environmental and paleo-ecological setting favourable for the
initial coral colonization at 2.6 Ma, we use well-developed proxies such as δ18O and δ13C
of planktonic (Globigerina bulloides) and of a collection of benthic foraminifera
(Cibicidoides wuellerstorfi, Discanomalina coronata, Cibicides lobatulus, Lobatulua
antarctica, Planulina ariminensis), benthic foraminiferal assemblages, as well as grain size
analysis. These proxies indicate variability in seawater temperature, salinity and density of
intermediate water masses from southern origin (Mediterranean, Bay of Biscay)
supporting cold-water coral settlement and initial development in the Porcupine
Seabight.
References: Kano et al. (2007) Age constraints on the origin and growth history of a
deep-water coral mound in the northeast Atlantic drilled during Integrated Ocean Drilling
Program Expedition 307. Geology, 35(11):1051–1054. |
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