Oxygen isotope compositions of quartz grains (4—16μm) from Chinese eolian deposits and their implications for provenance  

作　　者：侯圣山 杨石岭 孙继敏 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1003-1011,共9页中国科学（地球科学英文版）

基　　金：the National Natural Science Foundation of China(Grant No.49894170); the Chinese Academy of Sciences(Grant No.KZCX2-108).

摘　　要：Oxygen isotope compositions were measured in quartz grains extracted from a 7.0 Ma red clay-loess sequence at Lingtai and six late Pleistocene loess sediments (Malan loess). Results show that the changes in oxygen isotope compositions of Malan loess are basically controlled by the geochemical characteristics of the source materials, while the effect of weathering process after dust deposition could be minor. The oxygen isotope distribution of quartz grains from red clay at Lingtai is similar to that of the overlying loess-paleosol sequence, thus indicating that the red clay at Lingtai has the same eolian origin as the loess-paleosol deposits. Furthermore, the oscilla-tions of the isotope compositions in 4—16 mm-sized quartz grains may reflect the changes, to some extent, of the climatic systems of the source region.Oxygen isotope compositions were measured in quartz grains extracted from a 7.0 Ma red clay-loess sequence at Lingtai and six late Pleistocene loess sediments (Malan loess). Results show that the changes in oxygen isotope compositions of Malan loess are basically controlled by the geochemical characteristics of the source materials, while the effect of weathering process after dust deposition could be minor. The oxygen isotope distribution of quartz grains from red clay at Lingtai is similar to that of the overlying loess-paleosol sequence, thus indicating that the red clay at Lingtai has the same eolian origin as the loess-paleosol deposits. Furthermore, the oscilla-tions of the isotope compositions in 4—16 mm-sized quartz grains may reflect the changes, to some extent, of the climatic systems of the source region.

关 键 词：oxygen ISOTOPE ratio  quartz  atmosphere dust  provenance. 

分 类 号：P597[天文地球—地球化学]