Irena Miladinova¹, Arianna V. Del Gaudio¹, Gerald Auer^2,3, Patrick Grunert⁴, Werner E Piller⁵, Kurt Krenn⁶ and Walter Kurz¹, (1)University of Graz, Institute of Earth Sciences, Graz, Austria, (2)University of Graz, Department of Geobiology and Palaeoecology, Graz, Austria, (3)JAMSTEC, Department of Biogeochemistry, Yokosuka, Kanagawa, Japan, (4)University of Cologne, Institute of Geology and Mineralogy, Cologne, Germany, (5)Univ Graz, Graz, Austria, (6)University of Graz, Graz, Austria