The marine and freshwater stages of the Black Sea: initial results on sediment cores from the SE Black Sea covering the last ca. 140 kyrs
Abstract
Coring efforts during the last years rather suggested an extensive glacial sediment cover on most of the Black Sea slope areas not reachable with conventional gravity and piston coring devices. Here we present new sediment cores retrieved from the tectonically formed Archangelsky Ridge in the southeastern Black Sea during this year's RV Meteor cruise M72/5, which provide a first view into a most probably complete and undisturbed section of the last glacial period. Initial results from continuous XRF scanning on the split sediment cores suggest strong and immediate responses of the glacial Black Sea freshwater lake to the abrupt D-O climate oscillations of the last glacial period. At the base of one of the cores the complete marine unit deposited during the last global sea level highstand in Marine Isotope Stage 5 - the "Eemian" sapropel - is exposed. The intercalation of dark organic-rich intervals with light layers of aragonite precipitates and coccolith ooze in this unit demonstrates that the last marine stage of the Black Sea must have had a more complex history than we know from the Holocene. Despite the fact that the exact dating of this sequence will be challenging, the "Eemian" sapropel will provide the opportunity not only for a comparative study to the Holocene, but will also allow to understand how the marine Black Sea returned to a glacial freshwater lake. Furthermore, the finely laminated "Eemian" sapropel will provide insights into interannual to decadal-scale climate variability of the previous interglacial.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2007
- Bibcode:
- 2007AGUFMPP41C0678A
- Keywords:
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- 1605 Abrupt/rapid climate change (4901;
- 8408);
- 1630 Impacts of global change (1225);
- 4243 Marginal and semi-enclosed seas;
- 4901 Abrupt/rapid climate change (1605);
- 4914 Continental climate records