云南滇池现代沉积物^(210)Pb法的CF模式年龄研究  

A GEOCHRONOLOGICAL STUDY OF ^(210)Pb CF MODEL FOR THE RECENT SEDIMENTS OF DIANCHI LAKE, YUNNAN PROVINCE

作　　者：程致远[1] 梁卓成[1] 林瑞芬 卫克勤[1] 王道德[1] 

机构地区：[1]中国科学院地球化学研究所广州分部,510640

出　　处：《地球化学》1990年第4期327-332,共6页Geochimica

基　　金：国家自然科学基金

摘　　要：本文阐述了^(210)Pb法的CF模式年龄计算原理,并用此模式计算了云南滇池沉积柱样的年龄。发现CF模式年龄与普通的CA模式年龄有明显的差异,而^(228)Th/^(232)Th法和^(239,240)Pu分布都表明CF模式年龄是可靠的。此年龄结果显示了近一百年来滇池的沉积通量是变化的。210Pb geochronology has been widely applied to dating recent sediments in lakes, estuaries, and coastal marine environments. In this paper, the Constant Flux of Supply model (CF) has been applied to calculating the ages and sedimentation rates of two sediment cores from Dianchi Lake, Yunnan Province, in comparison with generally used Constant Activity model (CA). The CA and CF models have given quite different predictions of the ages of sediment sections for these two cores. Meanwhile, the results of 228Th/232Th method and 239,240Pu distribution are consistent with the CF age and show some difference from the CA age. The CF model indicates that the sedimentation rates of Dianchi Lake were variable during the past 100 years, ranging from 140 mg/cm2/a to 225 mg/cm2/a. It is likely that the longterm variation in sedimentation rate is due to both natural and artificial processes.

关 键 词：^210PB 沉积物 滇池 CF模式 年龄 

分 类 号：P597.3[天文地球—地球化学]