Browsing by Subject "Sedimentation rate"

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    Dating the sea of Marmara sediments by a uniform mixing model
    (Elsevier, 1996) Gökmen, A.; Yıldız, M.; Erten, H. N.; Salihoğlu, İ.
    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.
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    Radiochronology of sediments from various regions of the Mediterranean Sea by direct gamma spectroscopy using natural 210Pb, 226Ra and fallout 137Cs
    (1992) Tadjiki, Soheyl
    The and profiles are determined at two locations in southern coast of Spain, Three locations in southern coast of Turkey and two locations in coast of Cyprus. Compaction-corrected sedimentation rates are derived for all locations using data. The rates range from 1..39± 0.12 crn.y"' (0.50±0.04 g.cm“^.y“^) to 0.08±0.01 cm.y“^ (0.039±0.003 g.cm~'^.y“^) (0.50±0.04g.cm"^.y~^). Except for BC-6A, for all of the locations the ^^’^Cs profile is used to compute sedimentation rates which are in a good agreement with those of '^^°Pb method. The result of the Constant Initial Concentration and Constant Rate of Supply dating models are in a good agreement with each other whereas in BC-6A and KS-1 cores only Constant Rate of Supply model is valid to calculate sedimentation rate. The flux of unsupported '^^°Pb vary between 0.74±0.01 pCi.cm“^ and 0.11 ±0.03 pCi.cm“^. The average depositional flux is found to be considerably low in the coast of Turkey and Cyprus, whereas it is found to be high in the coast of Spain.