Chronology,geochemical characteristics and protolith formation of low-grade metamorphic rocks from Baoligaomiao Formation in Aershan area,Da Hinggan Ling(Mts.)
Chronology,geochemical characteristics and protolith formation of low-grade metamorphic rocks from Baoligaomiao Formation in Aershan area,Da Hinggan Ling(Mts.)
The Baoligaomiao Formation,located in the Arshan area of the Da Hinggan Ling(Mts.),compri-ses a continental sedimentary-volcanic rock series,predominantly formed of sedimentary clastic rocks and andes-ites,which have undergone regional metamorphism and have been converted into the low greenschist facies.This study focuses on the zircon U-Pb dating and geochemical analysis of the low-grade metamorphic rocks of Baoligao-miaoFormation.By integrating lithologic petrographosed and metamorphic deformation characteristics,the research aims to reconstruct the protolith structure and explore the sedimentary setting.The results indicate that the LA-ICP-MS zircon U-Pb age of the metamorphic andesites in the Arshan area is approximately(312.1±1.2)Ma,belonging to the Late Carboniferous and Early Permian periods,and it is identified as part of Baoligaomiao Forma-tion.The protolith assemblage of Baoligaomiao Formation in the Arshan area is a typical terrigenous intermediate-acidic volcano-sedimentary lacustrine facies.The sedimentary tectonic environment is the intra-arc basin of the ac-tive continental margin,which is consistent with the tectonic environment of the Late Carboniferous-Early Permian in Erlian-Hegenshan ophiolite-accretionary complex.
关键词
宝力高庙组/锆石U-Pb定年/原岩建造/弧内盆地/阿尔山地区
Key words
Baoligaomiao Formation/zircon U-Pb dating/protolith formation/intra-arc basin/Aershan area
维普
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