Oxygen isotopic heterogeneity in the mantle: Evidence from clinopyroxene megacrysts of Nüshan, eastern China  

Oxygen isotopic heterogeneity in the mantle: Evidence from clinopyroxene megacrysts of Nushan, eastern China

作　　者：XIA Qunke Dallai Luigi CAO Hong CHEN Daogong WU Yuanbao CHENG Hao 

机构地区：[1]Department of Earth and Space Sciences,University of Science and Technology of China,Hefei 230026,China [2]Stable isotope lab of Centre di Studio per il Quaternario el'EvoluzioneAmbientale-CNR,University of Rome“La Sapienza",Italy [3]Anbui Institute of Geological Experiments,Hefei 230001,China

出　　处：《Chinese Science Bulletin》2002年第3期181-186,共6页

基　　金：This work was supported by the National Natural Science Foundation of China (Grant No. 49803002).

摘　　要：Major element, REE and oxygen isotopic com-positions of fourteen clinopyroxene megacrysts from Nushan, eastern China have been obtained. They are believed to rep-resent crystallization products of one mantle-derived alkali basaltic magma. Oxygen isotopic ratios are homogeneous within the same sample, but heterogeneous among different samples, δ18O values of these megacrysts are from 4.86‰ to 6.48‰. We suggest that the oxygen isotopic variation of cli-nopyroxene megacrysts should be inherited from their source magma, and the heterogeneity of source magma re-sults from contamination of subducted oceanic materials.Major element, REE and oxygen isotopic com-positions of fourteen clinopyroxene megacrysts from Nushan, eastern China have been obtained. They are believed to rep-resent crystallization products of one mantle-derived alkali basaltic magma. Oxygen isotopic ratios are homogeneous within the same sample, but heterogeneous among different samples, δ18O values of these megacrysts are from 4.86‰ to 6.48‰. We suggest that the oxygen isotopic variation of cli-nopyroxene megacrysts should be inherited from their source magma, and the heterogeneity of source magma re-sults from contamination of subducted oceanic materials.

关 键 词：OXYGEN isotope HETEROGENEITY laser FLUORINATION clino-pyroxene nushan. 

分 类 号：P595[天文地球—地球化学]