LITHOSTRATIGRAPHY OF THE MIOCENE SEDIMENTARY SEQUENCES IN STRYMON BASIN, NORTHERN GREECE

The Miocene sedimentary sequences in Strymon basin, Northern Greece are divided into the Lefkonas, Dafni, Houmnikon and Kriopigi Formations. The Lefkonas Formation is a new formal lithostratigraphic unit and consists of coarse poorly sorted terrigenous rocks as breccias, breccia-conglomerates, conglomerates in thick and very thick massive beds probably older than Maeotian age. The Dafni Formation is represented mostly of thin, medium and thick bedded biogenic limestones and is of Maeotian age. The Houmnikon Formation is dominated of interbedded thin to medium sandstones, silty clays, argillites and erosive-based, gravel and pebbly conglomerates. Lenses and seams of lignites occur in different levels. Limestone beds, up to 1.5 m thick are common in the upper parts of the succession. The age of the formation is proved as Pontian. The Kriopigi Formation is a new formal lithostratigraphic unit and is deposited in a monotonous clayey-limy-silty sedimentation with Pontian age. The sedimentological character of the Lefkonas Formation supports its alluvial fan and fluvial origin. The Dafni Formation represents shallow marine deposits indicated the first Miocene transgression in the Strymon basin. The sedimentation of the Houmnikon Formation is realized in small deltas, low salinity lagoons, lakes and rivers in the upper part of the succession. The Kriopigi Formation sediments are deposited in lacustrine environments.