DATING THE SEA-OF-MARMARA SEDIMENTS BY A UNIFORM MIXING MODEL

The sedimentation rates and Pb-210 fluxes on sediment surfaces were me asured in the north, northwestern and southwestern parts of the Sea of Marmara. Each core had varying thickness of constant Pb-210 activity regions followed by a decreasing part with sediment depth. The sedimen tation rates of the samples collected from the Bosporus and the Dardan elles could not be analysed due to the homogenization of activity in t he strong currents of these straits. A uniform mixing model is propose d for the simultaneous analysis of sedimentation rates, Pb-210 fluxes and mixing depths from the experimental data. In this model, the param eters were obtained by minimizing the multi-dimensional parameter spac e using a grid search algorithm. The Pb-210 fluxes were found to be ab out 0.048 Bq cm(-2) year(-1) for all sampling sites. The mass sediment ation rates were 0.19 and 0.073 g cm(-2) year(-1) at the shelves of th e Bosporus and the Dardanelles and 0.055 and 0.064 g cm(-2) year(-1) i n the northwestern and middle northern basins, respectively, of the Se a of Marmara. Copyright (C) 1996 Elsevier Science Limited