长江河口区水体的锶同位素地球化学——对水与沉积物相互作用过程的反映  

STRONTIUM ISOTOPE GEOCHEMISTRY OF CHANGJIANG (YANGTZE RIVER) ESTUARINE WATERS: IMPLICATIONS FOR WATER-SEDIMENT INTERACTION

作　　者：王中良[1] 刘丛强[1] 

机构地区：[1]中国科学院地球化学研究所环境地球化学国家重点实验室,贵州贵阳550002

出　　处：《地球与环境》2004年第2期26-30,共5页Earth and Environment

基　　金：国家杰出青年科学家基金(49625304);国家攀登计划项目(95 预 39)

摘　　要：为了解长江河口区的水体混合过程和水与沉积物或颗粒物的相互作用过程,对长江河口水的87Sr/86Sr及Sr元素浓度进行了测定,结果显示:与世界河流平均值(Sr为78μg/L,87Sr/86Sr为0.7119)相比,长江水具有明显的高Sr(130μg/L)低87Sr/86Sr比值(0.7105)的特点。在长江口水体混合过程中,锶同位素没有象其它河口那样显示简单的两端员理想混合模式,而是在距河口约30～40km的地点出现87Sr/86Sr的突然升高,水体悬浮颗粒物(SPM)浓度也在同一区域出现升高现象。这可能是该区水体和沉积物相互作用比较强烈而引起沉积物与上覆水体发生物质交换。The Sr concentrations and^(87)Sr/^(86)Sr ratios of the Changjiang estuarine waters were measured. The results showed that the Changjiang River water has higher Sr concentrations (130μg/L) and lower^(87)Sr/^(86)Sr ratios (0.7105) as compared with the average values (0.7119 for^(87)Sr/^(86)Sr and 78μg/L for Sr) of global rivers. Strangely, no conservative mixing process of Sr isotopes was observed between fresh water and seawater during estuarine mixing, as the same as in other estuaries throughout the world, and there is an abrupt rise of^(87)Sr/^(86)Sr ratios at the salinity region about 32 to 42 km from the mouth of the estuary. This abrupt rise of^(87)Sr/^(86)Sr is mostly ascribed to the strong water-sediment interaction, because there exists the same rise of suspended particulate materials at the same sampling stations.

关 键 词：^87Sr/^86Sr 长江河口 水体混合 水/沉积物作用 

分 类 号：X142[环境科学与工程—环境科学]