通过分析东海嵊泗列岛嵊山黄土、浪岗山黄土的CaCO3特征,发现其含量极低,仅为0.1%左右,远低于内陆黄土,这是由于降水量大、剖面厚度小及周围多火山活动等因素共同作用的结果。按成因划分,嵊泗黄土中的CaCO3属于后期淋溶残余型,不适于作为恢复当地古环境的替代指标。与基本在同一直线上的兰州、渭南、南京及嵊山等地黄土中的CaCO3平均含量进行比较,发现其由西北向东南均匀递减,这是由于风尘黄土地层的淋滤作用和Ca(HCO3)2的淀积作用强度对降水量变化的响应速度不同的结果。
We analyzed the content of CaCO3 in the loess of Shengshan Island and Langgangshan Islands, and found the content is only about 0.1%, which is far below that in other loess sections. That should be caused by high precipitation, thin thickness of the section and lots of volcanic eruptions around. The CaCO3 in the loess of Shengshan Island and Langgangshan Islands belongs to deuterogenic residual CaCO3, and cannot be used to reflect paleoclimate. We contrast the content of CaCO3 in the loess of Shengshan Island and Langgangshan Islands with other loess sections, and find the content of CaCO3 in the loess is decreased equably, which should be the result of different velocity of eluviate and illuviate caused by precipitation changes.