西北地质2018，Vol.51Issue(1)：23-33,11.
甘肃北山红岩井西南似斑状二长花岗岩LA-ICP-MS锆石U-Pb定年及其地质意义
Zircon LA-ICP-MS U-Pb Dating of the Porphyritic Monzonitic Granite from Southwest Hongyanjing in Beishan Area, Gansu Province and Its Significance
摘要
Abstract
In this paper,the chronologic and geochemical researches were carried out on the porphyritic monzonitic granite in Southwest Hongyanjing.The zircon LA-ICP-MS U-Pb dating results show that the zircon U-Pb age of the intrusions is (402.2±4.4) Ma,which indicates that this intrusion was formed in the Early Devonian.Petrochemical and Geochemical data indicate that the porphyritic monzonitic granite are characterized by high Si (68.12％～75.76％) and high alkali (7.69％～9.91％),with A/CNK value of 1.4～1.5.Such geochemical characteristics,such as the rittmann index in sigma (σ) =1.8～3.8 (average 2.38),indicate that this intrusions belongs to the calc-alkaline strong peraluminous series.It displays higher total REE content (∑REE=175.4～296.76).Trace elements HFSE and Y are well concentrated,but Ba,Sr,Eu,P,and Ti are poorly concentrated.The comprehensive analysis also suggests that the granite is strongly peraluminous S-type granite of the calc-alkaline suite,which was formed in the post-orogenic tectonic environment.关键词
甘肃北山/似斑状二长花岗岩/LA-ICP-MS锆石U-Pb年龄/早泥盆世Key words
Beishan of Gansu Province/porphyritic monzonitic granite/LA-ICP-MS zircon U-Pb dating/Early Devonian分类
天文与地球科学引用本文复制引用
刘明强,朱永新..甘肃北山红岩井西南似斑状二长花岗岩LA-ICP-MS锆石U-Pb定年及其地质意义[J].西北地质,2018,51(1):23-33,11.基金项目
中国地质调查局“甘肃红泉地区1∶5万K46E014023等5幅区调地质调查”(1212011220371)、中国地质调查局“中国矿产地质与成矿规律综合集成和服务(矿产地质志)”(DD20160346) （1212011220371）
