Early Neoproterozoic Granite-Gneisses of the Junggar Alataw(Southeastern Kazakhstan):Age,Petrogenesis and Tectonic Implications  

作　　者：Nadezhda KANYGINA Andrey TRETYAKOV Dmitriy ALEXEIEV Kirill DEGTYAREV Anfisa SKOBLENKO Natalia SOLOSHENKO Boris ERMOLAEV 

机构地区：[1]Geological Institute,Russian Academy of Sciences,Moscow 119017,Russia [2]A.N.Zavaritsky Institute of Geology and Geochemistry,Ural Branch of the Russian Academy of Sciences,Yekaterinburg 620016,Russia

出　　处：《Acta Geologica Sinica(English Edition)》2024年第1期67-82,共16页地质学报（英文版）

基　　金：financially supported by the Russian Science Foundation (RSF) (Grant No. 22-77-00082);financially supported of grant 075-15-2021-680 of the Ministry of Science and Higher Education of the Russian Federation

摘　　要：The combined petrographic,petrological,geochemical and geochronological study of the Neoproterozoic gneisses of the Sarychabyn and Baskan complexes of the Junggar Alataw of South Kazakhstan elucidate the Precambrian tectonic evolution of the Aktau–Yili terrane.It is one of the largest Precambrian crustal blocks in the western Central Asian orogenic belt.The U-Pb single-grain zircon ages indicate that granite-gneisses formed from the same source and crystallised in the early Neoproterozoic ca.930–920 Ma.The chemical composition of gneisses corresponds to A2-type granites.The whole-rock Nd isotopic characteristics(εNd(t)=−4.9 to−1.0 and TNd(DM-2st)=1.9 to 1.7 Ga)indicate the involvement of Paleoproterozoic crustal rocks in magma generation.Early Neoproterozoic ca.930–920 Ma A-type granitoids in the Aktau–Yili terrane of South and Central Kazakhstan might reflect within-plate magmatism adjacent to the collisional belt or a local extension setting in back-arc areas of the continental arc.

关 键 词：granitoid magmatism geochemistry geochronology Sm-Nd isotope systematics NEOPROTEROZOIC Junggar Alataw Kazakhstan Central Asian orogenic belt 

分 类 号：P588.3[天文地球—岩石学] P534.3[天文地球—地质学] P597.3