论文摘要
The Songnen Massif is located in the eastern Central Asian Orogenic Belt, and its early stages of tectonic evolution remain controversial. Zircon U–Pb dating and geochemistry data were collected from Neoproterozoic rocks in the Songnen Massif of NE China, with the aim of understanding the correlation between the Neoproterozoic magmatism in the Songnen Massif and the evolution of the Rodinia supercontinent.The zircon U–Pb dating indicates that the Neoproterozoic magmatism within the Songnen Massif can be subdivided into four stages:（1） 929-927 Ma quartz-syenitic and syenogranitic gneisses,（2） 911-895 Magranitic gneisses,（3） 871 Ma granitic pegmatites, and（4） 850–841 Ma gneissic granodiorites（Luan et al., 2017 a, 2019）. Associated metamorphisms can also be subdivided into two stages, i.e., the 492 Ma and 546-530 Ma, suggesting that the study area underwent two stages of metamorphism during the late Pan-African（Luan et al., 2019）. The petrographical and geochemicaldata indicate that the 929-927 Ma syenitic rocks most likely originated from enriched mantle sources, which were metasomatized by subducted sediments and underwent fractional crystallization during ascension.The 911-895 Ma granitic gneisses were generated by the partial melting of ancient thickened lower crustal material（Luan et al., 2019）. In comparison, ～850–841 Mamagmatism formed from a primary magma generated by partial melting of ancient crustal material（Luan et al., 2019）. Combined with our previous studies, it is suggested that the ～929–927 and 911–895 Ma magmatism were formed in a convergent margin related to compressive orogenesis, whereas the ～871 and 850-841 Ma magmatism formed in an anorogenic setting related to either a post-orogenic tectonic event or the onset of Neoproterozoic continental rifting, consistent with the evolution of the Rodinia supercontinent.The data presented in this study indicate that the assembly and breakup of the Rodinia are also recorded within the Songnen Massif.
论文目录
文章来源
类型: 国际会议
作者: LUAN Jinpeng,XU Wenliang,YU Jiejiang
来源: 第九届世界华人地质科学研讨会 2019-06-01
年度: 2019
分类: 基础科学
专业: 地质学,地质学
单位: College of Earth Sciences, Jilin University
分类号: P534.3;P588.3
DOI: 10.26914/c.cnkihy.2019.028299
页码: 46
总页数: 1
文件大小: 56k
下载量: 1