| Five sediment cores collected in May, 1992 by the R / v “science 1” from the South Yellow Sea were studied. To evaluate the modern sedimentation rates and sedimentary environment, 210Pb avtivity was determined by α spectrometer. Contents of Ca, Sr, Fe, Ti and Cu were determined by X-ray fluorescent analysis. Huanghe River is rich in Ca and Sr, while Changjiang River sediment is rich in Cu and Fe (Zhao et al., 1991).
Obtained 210Pb dating indicated that in the western part of the Yellow Sea the sedimentation rates decrease gradually from north to south and then to east. Based on the sedimentation rates at coring station C-8 (0.67cm/a), KC-11 (0.43cm/a), KC - (0.32cm/a) and KCII-8 (0.24cm/a), and the contents of Ca (2.36%), Sr (0.0161%), Fe(3.25%), Ti(0.41%), Cu(0.0039%) at the coring station C11-8, it was inferred that a large quantity of material from the Huanghe River was carried by coastal current to the above stations.
In the central part of the South Yellow Sea, there is a patch of fine-grained mud. Based on the profiles of 210Pb activity and the contents of Ca (1.10%), Fe (4.73%), Ti (0.50%), Cu (0.0057%) and Sr (0.0133%), and the sedimentation rates of core KC-6 (0.17 cm/a) and C2-2 (0.18 cm/a), it is generally accepted that the mud is multisource sediment and the sedimentary environment is relatively stable.
In the south part of the Yellow Sea, that is the pathway of the Yellow Sea warm current where the profiles of 210Pb activity in the upper 5cm of cores (C19-7 and C17-5) appeared mixing zone. It is inferred that the sedimentation in the coring region was dominated by the relatively active hydrodynamic condition. So stations C17-5 and C19-7 has the lowest sedimentation rates (about 0.13 and 0.11 cm/a respectively). |
