论沉积强度——以南黄海为例

ON SEDIMENTATION INTENSITY IN SOUTH YELLOW SEA

本文在同位素^(210)Pb测定沉积速率的基础上,提出了“沉积强度”的概念,并以南黄海为例划分了不同沉积强度区,同时探讨了其形成机制。

The sedimentation rates in the South Yellow Sea were determined based on measurements of 210Pb for the first time. It ranges from 0 to 0.67 cm/a, with an average of 0.2 cm/a.It is well known that the same sedimentation rate can be considered great, but small in another. So sedimentation intensities in different areas can't be classified by a same rate value. Instead, they should be classified by a relative standard, that is, intensity index (i):i=r/Rwhere r is sedimentation rate; R is average sedimentation rate. When i is greater than l,it indicates strong sedimentation; less than 1, weak sedimentation; greater than 2, very strong sedimentation; less than 0.5, very weak sedimentation.Based on the intensity index mentioned above, the sedimentation intensity areas in the South Yellow Sea have been distinguished. Strong areas are located on the south side of Shandong Peninsula, outside of old Huanghe River delta and east coast. Weak areas are mainly the Yellow Sea Warm Current passed zone and the cold eddy area. Very strong area is the middle part of south side of Shandong Peninsula, where the large amount of Huanghe River materials is deposited,and the very weak areas are near relict sediment and tidal sandy ridge areas.The main factors controlling the sedimentation intensity are material supply and current system. The most influencial factors are strong material supply and weak current; on the contrary, the less influencial factors are weak material supply and strong current.