Παλαιοκλιματολογικές έρευνες στο νότιο Αιγαίο Πέλαγος
The Aegean Sea has become an important area of the Mediterranean for paleoclimatic reconstruction as it combines rapid response and sensitivity to climate change of both large and local scale, recorded in the hydrological characteristics and finally in the sedimentary record of each marine basin. Ge...
| Main Authors: | , |
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| Format: | Doctoral or Postdoctoral Thesis |
| Language: | Greek |
| Published: |
University of Patras
2020
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| Subjects: | |
| Online Access: | http://hdl.handle.net/10442/hedi/48898 https://doi.org/10.12681/eadd/48898 |
| Summary: | The Aegean Sea has become an important area of the Mediterranean for paleoclimatic reconstruction as it combines rapid response and sensitivity to climate change of both large and local scale, recorded in the hydrological characteristics and finally in the sedimentary record of each marine basin. Geographical location and complex geomorphology of the separate sea basins in the Aegean, affect the characteristics and the circulation of each marine water mass hosted by the different sea basins. This dissertation gathers geochemical and micropaleontological data from sediments from a small marine basin, the Tilos-Symi basin, located in the South Aegean Sea. The location and geomorphology of this basin, with the specific characteristics of a relatively small, isolated, coastal area of moderate depth, provide the advantages of a "natural laboratory", enabling the investigation of the impact of climatic events on the biogeochemical parameters of this marine ecosystem. The study mainly focuses on the Holocene and the deposition of the most recent sapropel and is based on very high resolution analysis of micropaleontoological data, combined with analyses of geochemical parameters. The sedimentary record is derived from a gravity core 381 cm long, in which the layers of sapropel S1 extend between 130-185 cm (6.19-10.16 ka BP). Two layers of sapropel were identified, including an interruption on the horizon 159.5-164 cm (8.21-8.54 ka BP). In addition to four AMS radiocarbon dates, the dating of the Z2 ash horizon from the Minoan eruption of the Volcano of Santorini was used as another check point. Organic carbon and nitrogen values in sapropel sediments exceed twice the corresponding values in background sediments. The Corg/N ratio is an important tool for the determination of the source of organic mater that may be mainly marine or mainly terrestrial. The stable isotopes δ15N and δ13Corg in sediments in combination with the above ratio lead to safer conclusions about organic matter produced in the ecosystem during ... |
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