Chronology, Geochemistry and Tectonic Implications of Late PalaeozoicIntrusions from South of Xiwuqi, Inner Mongolia
Liu Min
Zhao Hongtao
Zhang Da
Xiong Guangqiang
Di Yongjun
Abstract：In order to discuss the tectonic evolution of the Xing-Meng orogenic belt during the Late Palaeozoic, this study conducts a systematic study of the chronology, geochemical compositions and Hf isotopic characteristics of the quartz diorite, granodiorite and biotite granite from the south of Xiwuqi, which is situated at the southern margin of the southern Mongolian terrane.Zircon U-Pb dating indicates that the quartz diorite, granodiorite and biotite granite were emplaced at ca.330±2Ma, 274±1Ma and 271±1Ma~282±1Ma, respectively.The quartz diorite shows typical features of HMA and may be formed by melting of the subcontinental lithospheric mantle wedge induced by fluids released from partial melting of the subducted oceanic crust.The source of the studied granodiorite and biotite granite might be related to partial melting of juvenile crustal materials.Considering the regional geology, we infer that the Late Palaeozoic intrusions from the south of Xiwuqi were likely emplaced during the northward subduction of the Paleo-Asian Ocean plate beneath the southern Mongolian terrane.The Early Carboniferous quartz diorites are components of a continental arc-related magmatism, the Early Perrmian granodiorites and biotite granites are products of magmatism in a temporal back-arc extension setting during the northward subduction.
Keywords：Xing-Meng orogenic beltLate Palaeozoicarc-related magmatismHf isotopesubductiongeochemistrygeochronology
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：22( 527-548 )