calcareous clay
1.The surface sediments in the eastern South China Sea can be divided into 11 types based on the data of sediment color, grain size analysis, chemical and mineral compositions, microfossils, etc. These sediment types are named as clayey silt with rock debris, shell sand, clayey silt, calcareous clay, calcareous ooze, foraminifer ooze, pelagic clay, silty clay with micro-manganese nodules, siliceous clay, siliceous clay with volcanic ash, silty clay with volcanic ash.
2.The loess features appear mainly wind phase with the wind--water two phases by calculating grain size prameters and analysing the grain--size. The high content of clay(<5 μm), with the average of 54.32%, and mulistory calcareous loess layers indicate that it is formed in the condition of moist climate, dominating summer monsoon.
