Late Quaternary Evolution and Internal Structure of an Insular Semi-Enclosed Embayment, Kalloni Gulf, Greece

This study provides a comprehensive investigation of the sedimentary and tectonic evolution of Kalloni Gulf, a land-locked island embayment in the Northeast Aegean Sea. Information from a high-resolution seismic dataset was used to investigate the Late Quaternary seismic stratigraphy and internal structure of this shallow embayment. Four main seismic units were observed, bound by three key reflectors corresponding to main unconformities. The seismic units are related to periods of sea-level highstand and marine transgression, as well as to lowstand and marine regressions, dating back to the MIS 6 period. The chronostratigraphic framework of the observed units was based on previous work in the wider area and on global sea-level curves. In addition, information was gained regarding the hydrographic network of Kalloni Gulf, before the Holocene gulf flooding as well as during the Late Quaternary. The study also managed to identify faults and fault zones, which are distributed mainly along the southern and eastern margins of the gulf affecting both the gulf entrance physiography and the paleo-terrain of the eastern margin. With regard to specific structural features the fault zones are considered as strike-slip zones with an almost NNE-SSW orientation. These might be the submarine extension of the Aghia Paraskevi dextral strike-slip fault found onshore that dissects Lesvos, which is considered one of the main geohazards for the island. The results of the study are relevant not only for the reconstruction of the regional Quaternary geology, but also for broader research on Late Pleistocene-Holocene environmental change and tectonic-geodynamic processes in the wider northern Aegean Sea region.