Early Neoproterozoic Granite-Gneisses of the Junggar Alataw(Southeastern Kazakhstan):Age,Petrogenesis and Tectonic ImplicationsOACSTPCD
Early Neoproterozoic Granite-Gneisses of the Junggar Alataw(Southeastern Kazakhstan):Age,Petrogenesis and Tectonic Implications
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.
Nadezhda KANYGINA;Andrey TRETYAKOV;Dmitriy ALEXEIEV;Kirill DEGTYAREV;Anfisa SKOBLENKO;Natalia SOLOSHENKO;Boris ERMOLAEV
Geological Institute,Russian Academy of Sciences,Moscow 119017,RussiaA.N.Zavaritsky Institute of Geology and Geochemistry,Ural Branch of the Russian Academy of Sciences,Yekaterinburg 620016,Russia
granitoid magmatismgeochemistrygeochronologySm-Nd isotope systematicsNeoproterozoicJunggar AlatawKazakhstanCentral Asian orogenic belt
《地质学报（英文版）》 2024 (001)
67-82 / 16
This study was financially supported by the Russian Science Foundation(RSF)(Grant No.22-77-00082)and was conducted following the plans of the scientific research of the Geological Institute of the Russian Academy of Sciences.The authors are thankful to an anonymous reviewers for their constructive and valuable comments and recommendations.The authors are also grateful to Kristina Tretyakova and Vitaly Kravchenko for their support in the fieldworks.Natalia Soloshenko participated in the Geoanalyst Centre of the Ural Branch of the RAS in Ekaterinburg,conducting whole-rock Sm-Nd isotopic analyses.The modernization and comprehensive development of the Geoanalitik Center is financially supported of grant 075-15-2021-680 of the Ministry of Science and Higher Education of the Russian Federation.
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