Benthic foraminiferal evidence and paleoenvironmental evolution of Holocene coastal plains in the Aegean Sea (Greece)

摘要

Benthic foraminiferal composition of sedimentary successions during the last 7500 years, was investigated from boreholes drilled in three rather tectonically stable coastal areas of the Aegean Sea (Alykes Kitros, Lafrouda Thrace and Vravron Attica). The quantitative analysis of foraminiferal fauna enabled separation into two different groups that are supported by the analysis of modern benthic foraminiferal communities in the studied sites. Group A consists of Ammonia tepida and Haynesina germanica (closed lagoon assemblage), whereas the most common species of Group B (open lagoon assemblage) are Aubignyna perlucida, miliolids, Elphidium spp. and Ammonia spp. The foraminiferal composition integrated with radiometric dating provides information on Holocene paleoenvironmental changes in the studied coastal plains, related to sea-land interaction. Alykes Kitros and Lafrouda Thrace boreholes show a similar trend, with an open lagoonal fauna in the lower part, transitional upwards to closed lagoonal conditions. This environmental change has taken place after 6500 cal BP in Alykes Kitros and around 3000 cal BP at Lafrouda Thrace. The benthic communities of Vravron Attica borehole sediments seem to represent continuously an open lagoon/shallow marine environment from 4700 to 400 cal BP.