Chemical weathering history of the southern Tajikistan loess and paleoclimate implications  

作　　者：丁峰 丁仲礼 

机构地区：[1]Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China

出　　处：《Science China Earth Sciences》2003年第10期1012-1021,共10页中国科学（地球科学英文版）

基　　金：the National Natural Science Foundation of China(Grant Nos.4880231,40202016);Innovation Program of CAS(Grant No.KZCX2-108).

摘　　要：Major chemical elements and Rb, Sr, Ba abundances were measured for loess samples from Chashmanigar loess-soil sequence in southern Tajikistan. And the degree of element loss and intensity of weathering of the samples were calculated. From these calculations we found that the paleosol horizons of the Chashmanigar section were chemically weathered to some extent and the weathering intensity of the soils is stronger than that of loess horizons, indicating that paleosols in southern Tajikistan were deposited in relatively warm and humid interglacial ages. In addition, the southern Tajikistan loess deposited before 0.9Ma BP was more intensely weathered than that deposited after 0.9Ma BP, which may imply the intensification of aridity in this area since 0.9Ma BP.Major chemical elements and Rb, Sr, Ba abundances were measured for loess samples from Chashmanigar loess-soil sequence in southern Tajikistan. And the degree of element loss and intensity of weathering of the samples were calculated. From these calculations we found that the paleosol horizons of the Chashmanigar section were chemically weathered to some extent and the weathering intensity of the soils is stronger than that of loess horizons, indicating that paleosols in southern Tajikistan were deposited in relatively warm and humid interglacial ages. In addition, the southern Tajikistan loess deposited before 0.9Ma BP was more intensely weathered than that deposited after 0.9Ma BP, which may imply the intensification of aridity in this area since 0.9Ma BP.

关 键 词：TAJIKISTAN loess  element ratios  chemical weathering  QUATERNARY paleoclimate. 

分 类 号：P512.2[天文地球—地质学]