清江流域水系中高Cd沉积物的物源浅析  

Sources Analysis of Cd in Qingjiang Stream Sediment,Hubei Province

作　　者：杨东[1] 李方林[2] 夏锦霞[1] 杨军 

机构地区：[1]中国地质大学研究生院,武汉430074 [2]中国地质大学地球科学学院,武汉430074 [3]湖北地质调查院,武汉430030

出　　处：《地质科技情报》2009年第1期99-104,共6页Geological Science and Technology Information

基　　金：中国地质调查局项目"沿江冲积带镉及其他元素生态地球化学评价"(06010017)

摘　　要：利用Mapgis的空间分析功能和多元统计分析等方法,对清江流域4 180个水系沉积物样品中重金属元素Cd质量分数与区域出露地层的对应关系进行了研究,并结合区内部分地层岩石样品Cd的质量分数特征来揭示清江流域水系沉积物中Cd的物质来源。研究结果表明,高Cd沉积物(>0.3 mg/kg)样品采样点主要分布于二叠系和三叠系等地层,二叠系和三叠系的贡献因子分别为2 318.40和2 230.36(mg.km2)/kg,占所有地层贡献因子的65%。水系沉积物Cd高质量分数主要受二叠系和三叠系岩层的控制,同时还受到Cd自身地球化学性质和铁锰等氧化物吸附作用的影响。高Cd沉积物(>0.3 mg/kg)的元素共生组合特征与黑色岩系的元素富集程度相关,清江流域水系沉积物中的Cd主要来源于黑色岩系。石煤风化土壤的流失和石煤矿点开采过程中尾渣、废水的排放可能是清江流域水系沉积物Cd的重要点污染源。4 180 samples of stream sediment have been studied by Spatial Analysis of Mapgis and Multivariate Statistical Analysis in order to find the correlation between the distributions of strata and of Cd concentrations in Qingjiang River stream sediments. The sources of Cd also have been identified through analyzing the characteristics of Cd concentration in part of stratum rocks based on the parallelism relationship between the distribution of stratum and Cd. The results show that higher Cd concentration samples（≥0.3 mg/kg） are distributed in Permian and Triassic strata. The contribution factor of Permian and Triassic strata were 2 318.40 and 2 230.36（mg · km^2）/kg respectively, accounting for 65% of all contribution factors. Higher Cd concentration of sediments was controlled by Permian and Triassic strata, and also affect- ed by the geochemical properties of Cd as well as the sorption of iron and manganese oxides. The element paragenetic association of sediments with higher Cd concentration （≥0.3 mg/kg） was related to the element enrichment of black rock series. Therefore, the weathering and loss of black rock series may be the major Cd sources of stream sediment. The weathering and loss of stone coal and the tailings and wastewater＇s emission in coal mining may be the important sources of higher Cd concentration of sediments.

关 键 词：镉 黑色岩系 贡献因子 清江 

分 类 号：P595[天文地球—地球化学]