大凌河与辽河入海口沉积物黏土矿物组成研究

A study of clay minerals in estuarine sediments of Daling River and Liaohe River

采用X射线物相分析,对大凌河和辽河13个表层沉积物样品和4个柱状样中168个现代沉积物样品的主要黏土矿物含量组成进行分析。研究结果表明:大凌河沉积物黏土矿物组合为蒙脱石-伊利石-高岭石-绿泥石,辽河沉积物黏土矿物组合为伊利石-蒙脱石-绿泥石-高岭石。大凌河沉积物中蒙脱石与伊利石百分含量比值多大于1,而辽河沉积物该比值都小于1,且通过ISKc端元图能较清晰地区分两类沉积物,黏土矿物可以作为两条河流沉积物的判别标志。大凌河流域和辽河流域均以物理风化为主,辽河流域物理风化略强。流域内地质背景和气候条件等因素的差异造成了两条河流沉积物黏土矿物组成的不同。

The clay minerals of 13 surface sediments and 168 modern sediments of 4 sediment cores in Daling River and Liaohe River were analyzed with the X-ray diffraction method.The results show that smectite-illite-kaolinite-chlorite is the main clay mineral assemblage of Daling River sediments,while the main assemblage of Liaohe River is illite-smectite-chlorite-kaolinite.The most ratios of smectite content to illite content of Daling River are greater than 1,while the ratio values of Liaohe River are less than 1.It is clear that the two river sediments are distinguished by the triangular map with end members of illite,smectite,and kaolinite+chlorite(ISKc).Clay minerals can be used as a discriminative index of the two river sediments.The results reveal similar degrees of physical weathering in Daling River Basin and Liaohe River Basin,and a slight intensity in Liaohe River Basin.The geological background and climatic conditions in the basins result in the difference in the composition of clay minerals in the sediments of the Daling River and Liaohe River.