First results of a geophysical Pre-Site Survey in the Philippi peat basin, eastern Makedonia, northeastern Greece

Under the administration of the Centre of Quaternary Science & Geoarchaeology (QSGA) the Collaborating Research Centre (CRC) 806 „Our Way to Europe“ started in summer 2009. The project is founded by the German Research Foundation (DFG). In this CRC the QSGA is concerning about the dispersal of modern Man from Africa and the permanent establishment of Man in Central Europe (QSGA, 2009). The fieldworks, done during the summer 2009 in Greece by the Institute for Geology and Mineralogy from the University of Cologne, was targeted as a preside survey to find therein after a location for a drilling. This drilling is aimed as an extendend paleoclimatic research analog to the works of Müller but with the intention to drill at greater depths. With different geophysical methods (TEM, VES, RMT) the quality of the Tenaghi-Philippon-Basin as a historical climate archive should be evaluated. The Tenagi-Phillipon Basin is the south-west part of the larger Drama Basin. The Drama Basin is an intermontane basin lying in-between the metamorphic rocks of the Rila-Rhodope-Massif. It was generated during a late brittle deformation in Miocene times after the exhumation of the Southern Rhodope Core Complex (SRCC) in middle Eocene times. Therefore, the SRCC and the associated Negoene sedimentary basins offer the most complete record of the about 40 My of Aegean extension. The dimension of the basin and its sediment deposition is tectonically as well as climatically controlled. The sedimentation of peat endured over the last 700 000 yr until the drainage of the basin in 1931 to 1944 for agricultural usage. The sediments of the Philippi Sub-Basin covers an area of about 55 km² and reaches a thickness of about 400 m, thus it is the thickest known peatland in the world. The sediments can be divided in two Beds. Bed I is a peat free of intercalations with a thickness of about 190 m. Bed II are limnic sediments with a lot of intercalations and a thickness up to 400 m.
   The location for the measurements was placed at the largest extension of the basin between the villages Krinides and Eleftheroupolis. This poster presents the first results of the TEM-Fast measurements along two profiles. One profile was conducted from the north (Krinides) to the south (Eleftheroupolis), to verify the overall basin's structure. The second profile was arranged rectangular to the first one and stretches from the west (Stathmos) to the east (Dato). The results of the pseudo 2D inversion show a general conductivity distribution of a basin structure: A max. 100 m thick 7 Ωm layer (Bed I) over a more resistive (> 100 Ωm) half space which can be assumed to be Bed II. This finding correlates with cores that were drilled and analysed by Melidonis. The thickness of Bed II could not be verified from the data, due to the fact that the depth of penetration is not sufficient to detect the top of the bedrock. Plotting the data shows a general basin structure from the north to the south with its declining towards the centre and a possible thickness of the peat of Bed I.