现代地质2017，Vol.31Issue(6)：1147-1156,10.
中天山卡瓦布拉克杂岩带中-基性岩的成因及其构造意义:元素地球化学和Sr-Nd-Pb同位素约束
Petrogenesis and Tectonic Implications of Intermediate Basic Rocks from Kawabulak Complex in Central Tianshan: Constraints from Elemental Geochemistry and Sr-Nd-Pb Isotopes
摘要
Abstract
The study of the petrogenesis of Kawabulak Complex has great significance to reconstruct Paleozoic oceanic-continental framework and tectonic evolution processes of southern central Tianshan.On the basis of mineralogical and petrological examinations,major and trace elements and Sr-Nd-Pb isotopes of the intermediate basic components from Kawabulack Complex are studied.The rock samples are mainly of low-K-tholeiite series with relatively high contents of Na.These rocks are relatively enriched in LREEs (Rb,U,Sr) and LILEs,and are depleted in HREE and HFSE (Nb,Ta,Zr).Sr-Nd-Pb isotopic geochemistry shows that the values of Isr range from 0.706 to 0.709,while εNd (t)values change from 6.84 to 9.76.They have relatively low Pb isotopic compositions characterized by (206 pb/204 Pb) i ＝ 18.015-18.239,(207 pb/204 Pb) i =15.573-15.593 and (208pb/204pb)i =37.871-38.207.Combining with previous studies and regional geology,the authors have come to the conclusion that the parent magma of intermediate-basic rocks from Kawabulak Complex,as a product of island arc magmatism,is originated from a juvenile lithospheric mantle that was previously metasomatized by subduction zone fluids/melts in the Paleozoic,representing a section of Late Paleozoic magmatic arc of this region.关键词
中天山/卡瓦布拉克/中-基性岩类/Sr-Nd-Pb同位素/岩石成因Key words
central Tianshan/Kawabulak/medium-basis rock/Sr-Nd-Pb isotopes/lithology分类
天文与地球科学引用本文复制引用
麦地娜·努尔太,尼加提·阿布都逊,木合塔尔·扎日,吴兆宁,张龙..中天山卡瓦布拉克杂岩带中-基性岩的成因及其构造意义:元素地球化学和Sr-Nd-Pb同位素约束[J].现代地质,2017,31(6):1147-1156,10.基金项目
国家自然科学基金项目(41562010,41502213,41162006). （41562010,41502213,41162006）
