Unit:
Department of Geology and GeoenvirommentLibrary of the School of Science
Dissertation committee:
Κατερίνα Κούλη, Αναπλ. Καθηγήτρια, Γεωλογίας και Γεωπεριβάλλοντος, ΕΚΠΑ (επιβλέπουσα)
Μαρία Β. Τριανταφύλλου, Καθηγήτρια, Γεωλογίας και Γεωπεριβάλλοντος, ΕΚΠΑ
Fabienne Marret-Davies, Professor , University of Liverpool, UK
Καθηγήτρια Ασημίνα Αντωναράκου, ΕΚΠΑ
Μαρία Γεραγά, Καθηγήτρια, Γεωλογίας, Πανεπιστήμιο Πατρών
Ιωάννης Παναγιωτόπουλος, Επίκουρος Καθηγητής, Γεωλογίας και Γεωπεριβάλλοντος, ΕΚΠΑ
Kenneth Mertens, Dr, French Research Institute for Exploitation of the Sea, France
Original Title:
Depositional environment development and ecosystem response in the Gulf of Corinth during the Quaternary climatic cycles
Translated title:
Depositional environment development and ecosystem response in the Gulf of Corinth during the Quaternary climatic cycles
Summary:
The Gulf of Corinth (GoC) underwent multiple phases of connection and isolation from the Mediterranean Sea during the Quaternary global sea-level fluctuations. This study presents a comprehensive paleoenvironmental analysis of the Quaternary aquatic ecosystems in the GoC, focusing on organic-walled dinoflagellate cysts, Non-Pollen Palynomorphs, and paleoenvironmental (foraminiferal and diatoms) and geochemical data from IODP Exp. 381 during its onshore and offshore phases. The research spans the last 1.1 million years, exploring alternations between marine and brackish conditions during glacial-interglacial transitions. The study's unique contribution lies in the examination of the semi-isolated basin of the GoC, shedding light on paleoenvironmental and paleoclimatic conditions shaped by sea-level fluctuations, tectonics, and ocean circulation. The geological and tectonic context of the GoC, within the Hellenic arc system, adds complexity to the basin's evolution. The basin's formation, tectonic activity, and geological units, emphasizing its significance as a natural laboratory for research in continental rifting, seismicity, active tectonics, uplifting, and subduction processes. The Quaternary sedimentary record, accumulated over 2.5 km and reflecting the basin's complete geological history, unveils the interplay of sea-level fluctuations and sediment input from rivers. The study establishes the crucial role of the Rion Strait in connecting the GoC to the Mediterranean Sea and explores changes in connectivity during various Marine Isotope Stages (MIS). The micropaleontological analysis of dinoflagellate cyst assemblages provide insights into past salinity gradients and environmental responses to basin transitions. Distinct Dinoflagellate Super Zones (DSZs) reveal the complex history of the GoC, highlighting periods of isolation, brackish conditions, and marine connectivity. Each DSZ corresponds to specific MIS, describing environmental shifts during glacial and interglacial intervals. The life cycle of organic-walled dinoflagellates plays a critical role in the preservation of dinoflagellate cysts as reliable indicators of past environmental conditions. The detailed analysis of DSZs showcases the alternations between freshwater and marine conditions, providing a detailed understanding of the basin's dynamics. Comparison with other basins such as the Black Sea, Sea of Marmara, and Caspian Sea dinocyst assemblages’ underscores affinities and differences, emphasizing the importance of considering regional contexts. The study's correlation with onshore expedition data enhances its relevance, contributing to a holistic understanding of the GoC's Quaternary paleoenvironmental dynamics. The proxies mentioned above combined, suggest that the GoC was repeatedly isolated and reconnected to the Mediterranean Sea during global sea-level lowstands associated with glacials and marine water flowed into the basin during the eustatic highstands associated with interglacials. In summary, geological, tectonic, geochemical and micropaleontological perspectives facilitate to unravel the Quaternary environmental evolution of the GoC. The findings contribute valuable insights into basin dynamics, sea-level fluctuations, and regional climate variability.
Main subject category:
Science
Keywords:
Glacial/interglacial cycles, Sea-level change, Dinoflagellate cysts, Sea-surface salinity, Quaternary, IODP Exp.381
Number of references:
435
File:
File access is restricted until 2027-03-20.
PhD_thesis_Fatourou_E_2024.pdf
22 MB
File access is restricted until 2027-03-20.
