oa An Integrated Biogeochemical and Geodynamic Model for a Riverine Originated Shallow Lacustrine Basin (Western Turkey)

A limited number of inland lakes, formed during the earlier stages of the Holocene, are still present in near coastal areas of Eastern parts of the Aegean Sea. The coastal morphology and particularly the formation of these shallow lacustrine basins are predominantly controlled by the host-graben structures, such as Gediz, Kucuk and Buyuk Menderes in Central-Western Anatolia ( Hakyemez et al., 1999 ). This study represents an integrated geodynamic and biogeochemical approach, with a great potential for paleo-environmental reconstructions of such riverine originated shallow lakes.

As a pilot monitoring site, we focused on Lake Marmara basin, which developed in a residual-branch on the northern sector of Gediz Graben and paleo-Gediz valley. During the drilling campaign in 2003, the maximum water depth was 4.5m in the western depositional centre of the lake (WD) and even lower (4m) in the eastern depo-centre (ED). These two sub-basins are currently separated by a north-south striking ridge, as evidenced by reduced water level and geophysical (ground penetrating radar) data. Two cores one from each depositional centre, of 140cm (H3:WD) and 145cm (H5:ED) length, respectively, were retrieved from the lake. The entire sediment archive of these cores covers the last 10ka span environmental history of the basin.