Dating the sea of Marmara sediments by a uniform mixing model

Abstract

The sedimentation rates and ‘t”Pb fluxes on sediment surfaces were measured in the north, northwestern and southwestern parts of the Sea of Marmara. Each core had varying thickness of constant 2’0Pb activity regions followed by a decreasing part with sediment depth. The sedimentation rates of the samples collected from the Bosporus and the Dardanelles could not be analysed due to the homogenization of activity in the strong currents of these straits. A untform mixing model is proposed for the simultaneous analysis of sedimentation rates, “‘Pb fluxes and mixing depths from the experimental data. In this model, the parameters were obtained by minimizing the multi-dimensional parameter space using a grid search algorithm. The 2’0Pbfluxes were found to be about 0.048 Bqcm-’ year-t for all sampling sites. The mass sedimentation rates were 0.19 and 0.073gcm-2 year-’ at the shelves of the Bosporus and the Dardanelles and 0.055 and 0.064 g cm-’ year -’ in the northwestern and middle northern basins, respectively, of the Sea of Marmara.