地质论评2018，Vol.64Issue(2)：405-417,13.DOI:10.16509/j.georeview.2018.02.008
辽宁后仙峪硼矿区混合岩的LA-MC-ICP-MS锆石U-Pb年龄:对硼矿成矿演化的制约
LA-MC-ICP-MS U-Pb Zircon Ages of Paleoproterozoic Migmatitized Granites from the Houxianyu Borate Deposit, Eastern Liaoning:Constraints on the Evolution of the Borate Deposits
摘要
Abstract
The Eastern Liaoning sedimento—metamorphic borate deposits located in the Paleoproterozoic volcanic—sedimentary rock series of Liaoning—Jining rift zone includes the Houxianyu boron—magnesite deposit,Wengquangou boron—iron deposit and Zhuanmiao—Yangmugan boron—magnesium deposit.It has been the main origin of boron in China.In this study,we have collected zircon for LA-MC-ICP-MS dating from the stripe-like granite(DSQ-08) and the tourmaline-bearing leucogranite(HXY-19) in the Houxianyu borate deposit.Zircons from the stripe-like granite have a magmatic oscillatory zoning with a Th/U ratio of 0.64～0.96 and a 207Pb/206Pb age of 2240 ± 4Ma.Zircons from the tourmaline-bearing leucogranite also has a clear magmatic oscillation zoning and have a Th / U ratio of 0.12 ～ 1.05 in the core and 0.41 ～ 1.08 in the edge respectively,in addition,thier corresponding 207Pb / 206Pb ages recorded 2157 ± 6Ma and 1932 ± 26Ma two growth events.The zircon edge of the tourmaline-bearing leucogranite is formed in the process of migmatitization,which records the partial melting event occurring in the lower part of the Liaohe Group at about 1.9 Ga,which is of great geological significance.The magmatic age of the stripe-like granites and the core age of the tourmaline-bearing leucogranite in the periphery of the orebodies are close to each other,indicating that the two rocks may be derived from partial melting of Paleoproterozoic volcanic—sedimentary rocks at about 1.9 Ga.Therefore,in combination with previous studies on boron isotopic geochemistry and petrography in the Houxianyu borate deposit,we believe that the zircon core U-Pb age in the leucogranite of the Houxianyu borate deposit can be basically determined the eruption of the ultramafic volcanic rocks and acid volcanic rocks at the early stage of the rift occurred in 2240 ～ 2157Ma,and the vapor deposition in this period formed the borate deposit initially.In the latter stage,strong partial melting and migmatitization occurred in 1932 ± 26Ma,and under the protection of ultramafic volcanic rocks,the borate deposit formed by boron mineralization and small-scale migration.关键词
LA-MC-ICP-MS锆石U-Pb年龄/后仙峪硼矿/混合花岗岩/部分熔融/混合岩化Key words
LA-MC-ICP-MS zircon U-Pb dating/Houxianyu borate deposit/leucogranite/Partial melting/Migmatitization引用本文复制引用
付燕刚,胡古月,李延河,范昌福,侯可军,赵悦..辽宁后仙峪硼矿区混合岩的LA-MC-ICP-MS锆石U-Pb年龄:对硼矿成矿演化的制约[J].地质论评,2018,64(2):405-417,13.基金项目
本文为国土资源部公益性行业科研专项经费项目(编号:201211074-2 200911043-20) （编号:201211074-2 200911043-20）
中国地质调查局二级项目(编号:DD20160040)的成果.This work was sponsored by Public Science and Technology Research funds projects (No.201211074-2 200911043-20) and Geological and Mineral Investigation of China Geological Survey (No.DD20160040). （编号:DD20160040）
