ZIRCON U-Pb DATING AND GEOCHEMISTRY OF THE EARLY CRETACEOUS GRANITIC ROCKS IN THE MIDDLE SECTION OF DAXINGANLING MOUNTAINS
CHEN Hui-jun1, ZHANG Yan-long2, WANG Qing-hai3, YANG Hao2, QIAN Cheng1, CHEN Jing-sheng1, QIN Tao1, WANG Yan1, WU Xin-wei1, ZHANG Yu-jin1
1. Shenyang Institute of Geology and Mineral Resources, CGS, Shenyang 110034, China; 2. College of Earth Sciences, Jilin University, Changchun 130061, China; 3. International Center for Geosciences Research and Education in Northeast Asia, Jilin University, Changchun 130026, China
Abstract：The Phanerozoic granites are widely distributed in the Daxinganling region, but the research on Mesozoic granites was relatively poor. The paper conducts a geochronological and geochemical study on the Early Cretaceous granites collected from Bijiadian pluton and Shenshan pluton on the west of Zhalantun in the middle section of Daxinganling Mountains, and discusses the petrogenesis and tectonic setting of the granitic rocks. The LA-ICP-MS zircon U-Pb dating indicates that the Bijiadian pluton is mainly composed of syenogranite and granite porphyry, with ages of 136±3 Ma, 139.5±0.9 Ma and 128.1±0.8 Ma, whereas the Shenshan pluton consists of mainly alkali-feldspar granites, with age of 119.3±0.8 Ma, which indicate that both of them were formed in the Early Cretaceous. The two plutons are geochemically characterized by high Si, low Ca, rich Alkali, negative Eu anomalies, enrichment of Rb, Th and U, and depletion of Nb and Ta, belonging to the weakly peraluminous high-K calc-alkaline series and quite similar to highly fractionated I-type granitoids. Combined with the petrological and geochronological features of the coeval granitoids in Daxinganling region, it is proposed that the formation of the Early Cretaceous granitic rocks was closely related to the delamination induced by the subduction of the Pacific plate.
陈会军, 张彦龙, 王清海, 杨浩, 钱程, 陈井胜, 秦涛, 汪岩, 吴新伟, 张渝金. 大兴安岭中段早白垩世花岗质岩石锆石U-Pb年龄及地球化学特征[J]. 地质与资源, 2015, 24(5): 433-443.
CHEN Hui-jun, ZHANG Yan-long, WANG Qing-hai, YANG Hao, QIAN Cheng, CHEN Jing-sheng, QIN Tao, WANG Yan, WU Xin-wei, ZHANG Yu-jin. ZIRCON U-Pb DATING AND GEOCHEMISTRY OF THE EARLY CRETACEOUS GRANITIC ROCKS IN THE MIDDLE SECTION OF DAXINGANLING MOUNTAINS. GEOLOGY AND RESOURCES, 2015, 24(5): 433-443.
2015, Vol. 24 
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