THE AGE OF THE DASHIQIAO FORMATION IN LIAOHE GROUP: Constraints from LA-ICP-MS Zircon U-Pb Dating of Acidic Volcanic Rocks
CHEN Jing-sheng1,2, AN Mao-guo3, DUAN Ming4, LIU Miao1, LI Bin1, YANG Fan1, LI Wei1, XING De-he1
1. Shenyang Institute of Geology and Mineral Resources, CGS, Shenyang 110034, China; 2. College of Earth Sciences, Jilin University, Changchun 130026, China; 3. Shandong Lunan Institnte of Geological Engineering and Exploration, Jining 272100, Shandong Province, China; 4. Tianjin Institute of Geology and Mineral Resources, CGS, Tianjin 300170, China
Abstract：Dashiqiao Formation, the important ore-bearing horizon in Liaohe Group, is lithologically composed of dolomite marble, calcite marble and mica schist. In this study, a layer of acidic volcanic interbed, rhyolitic breccia tuff, is founded in the marble of Dashiqiao Formation for the first time in Bahui Town, southern Liaoyang City. Based on the field occurrence, the acidic volcanic rock and the marble were deposited simultaneously. The clear oscillatory zoning and high Th/U ratio show that the zircons from the rhyolitic breccia tuff are magmatic origin. The LA-ICP-MS zircon U-Pb dating yields the age of 2171±11 Ma, which is the first accurate age for the Dashiqiao Formation. This age also constrains the sedimentary time of Langzishan Formation, Lieryu Formation and Gaojiayu Formation, which underlie the Dashiqiao Formation, to before 2171 Ma.
陈井胜, 安茂国, 段明, 刘淼, 李斌, 杨帆, 李伟, 邢德和. 辽河群大石桥组形成时代——来自酸性火山岩LA-ICP-MS锆石U-Pb测年的制约[J]. 地质与资源, 2017, 26(2): 105-110.
CHEN Jing-sheng, AN Mao-guo, DUAN Ming, LIU Miao, LI Bin, YANG Fan, LI Wei, XING De-he. THE AGE OF THE DASHIQIAO FORMATION IN LIAOHE GROUP: Constraints from LA-ICP-MS Zircon U-Pb Dating of Acidic Volcanic Rocks. GEOLOGY AND RESOURCES, 2017, 26(2): 105-110.
2017, Vol. 26 
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