|TITLE||PALEOENVIRONMENTAL EVOLUTION AND SEA LEVEL CHANGE IN SARONIKOS GULF (PIRAEUS COASTAL PLAIN AND ELEFSIS BAY, GREECE) DURING THE HOLOCENE|
|AUTHORS||Maria V. Triantaphyllou (1), Kosmas P. Pavlopoulos (2,3), Katerina Kouli (1), Olga Koukousioura (4), Margarita D. Dimiza (1), Elina Aidona (5), George Syrides (4), Alexandra Gogou (6), Aristomenis P. Karageorgis (6), Stella Kyrikou (1), Aggelos Pallikarakis (7), Odysseas Archontikis (1), Jean-philippe Goiran (8), Christos Anagnostou (6), Eric Fouache (2)|
- University Of Athens, Faculty Of Geology And Geoenvironment, Department Of Historical Geology-paleontology Athens (Greece)
- Paris-sorbonne University Abu Dhabi, Department Of Geography And Planning-umr 8185 Enec Abu-dhabi (United Arab Emirates)
- 3harokopion University Athens (Greece)
- Aristotle University Of Thessaloniki, School Of Geology, Department Of Geology Thessaloniki (Greece)
- Aristotle University Of Thessaloniki, School Of Geology, Department Of Geophysics Thessaloniki (Greece)
- Hellenic Centre For Marine Research, Institute Of Oceanography Athens (Greece)
- Agricultural University Of Athens, Department Of Natural Resources Management & Agricultural Engineering Athens (Greece)
- Centre National De La Recherche Scientifique (cnrs), Umr 5133-archÃ©orient, Mom Lyon (France)
|ABSTRACT||The joint application of benthic foraminifera, pollen and non-pollen palynomorphs, molluscs and magnetic susceptibility analyses in Piraeus coastal plain deposits resulted in the detailed study of palaeoenvironmental evolution of the area during the Holocene. The main factors that feature the evolution of the Piraeus coastal landscape have been described as the relative sea level rise in the Holocene due to glacio-hydro-isostatic changes, the tectonic stability of the area and the progradation of deltaic fans. Benthic foraminiferal assemblages at the lower part of the sequence revealed the dominance of Ammonia tepida coupled with increased presence of Haynesina germanica and molluscan species Cerastoderma glaucum, Abra spp. and Hydrobiidae, suggesting a typical inner lagoonal environment after 8700 BP. In the same interval, palynomorphs indicate soil erosion and increased riverine runoff. The high values of magnetic susceptibility confirm closed lagoon paleoenvironmental conditions. A gradually improved communication with the sea is recorded till 7800 BP, in the Early Neolithic. In the pollen spectra, the profound short-lived abundance peak of Abies and Artemisia may be related to a climatic deterioration event; the increase of Cerealia-type towards the upper part of this unit signals the first farming communities in the area.
Between 6800 and 5400 yr cal. BP, benthic foraminiferal assemblages and mollusc fauna suggest a shallow marine palaeoenvironment. In accordance, magnetic susceptibility values are low indicating the presence of marine deposits. Apparently, in this period Piraeus was an island in the centre of a wide shallow marine bay. Since about 4800 BP a closed oligohaline lagoon is once more evidenced that was used for grazing, as indicated by the coprophilous fungal remains of Sordaria and parasites. The human presence is inevitably detected since the Early Bronze Age by the increase of cultivars like Cerealia-type and Olea. After 2800 BP a marshy oligohaline depositional environment has been established. Magnetic susceptibility shows maximum values, thus implying both fresh water input and anthropogenic impacts. Cultivation and pastoral activities appear intensified during the Antiquity.
A comparison with a well dated marine record recovered from the nearby shallow bay of Elefsis, contributes to accurate estimations for the sea level rise rate in inner Saronikos gulf during the Holocene. At Elefsis bay the transition from aragonite-rich palaeolake sediments to fine-grained marine aluminosilicates marks the period when sea flooded the area.|