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| Titel |
Dynamics of Late Quaternary sapropel periods documented by micropaleontological and sedimentological data from North Aegean Sea |
| VerfasserIn |
Georgia Gkaniatsa, George Kontakiotis, Assimina Antonarakou, Hara Drinia, George Anastasakis |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250145374
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| Publikation (Nr.) |
 EGU/EGU2017-9310.pdf |
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| Zusammenfassung |
| Located at the interface of the mid/high latitude climate system and affected by the North
Atlantic Oscillation and the monsoonal system over Africa, the Mediterranean Sea
has a unique potential to record the occurrence and phasing of climatic changes in
both systems. In particular, the eastern Mediterranean Sea is more sensitive and
faster responding to external forcing than the open ocean due to smaller size and
partial isolation. A manifestation of the high sensitivity of the eastern Mediterranean
sedimentary environment to climatic forcing is the periodic deposition of dark colored and
organic matter rich sediments, termed “sapropels”. In particular their formation is
closely correlated with the reduction in ventilation, due to low salinity surface water
layer, leading to anoxia at the bottom and preservation of organic matter, and/or
the increase in primary productivity in the photic zone. To address which factor is
more responsible for the sapropel’s formation, a high-resolution study of planktonic
foraminiferal abundances in two cores from North Aegean was carried out. Their
response reflects the essential information about the paleoceanographic evolution in
the water column in terms of stratification and productivity during the different
sapropel events covering the last 90 kyrs. Cores M 22-67 and M22-68 were recovered
from the water depths of 175 and 305 m respectively in the Chios Basin (North
Aegean Sea). Both cores approximately span the last 90 ka, exposing the most recent
S1 and the older S3 sapropels. They particularly exposed at very high resolution
compared to most occurrences throughout the eastern Mediterranean, because of the
highest sediment accumulation rates occurred in the study basin. Application of
this information to the study hemipelagic sediment cores, through the planktonic
foraminiferal analyses, suggests that we further contribute to existing evidence of climatic
instability during sapropel deposition in eastern Mediterranean Sea. Moreover, using
sedimentological observations, we aim to determine the dynamics of sediment delivery,
redox conditions and preservation during the formation of these sapropel events. |
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