地质科技情报2017，Vol.36Issue(3)：92-102,11.DOI:10.19509/j.cnki.dzkq.2017.0312
中蒙边境额仁淖尔地区包饶勒敖包石英闪长岩锆石U-Pb年龄及构造意义
LA-ICP-MS Zircon U-Pb Age and Its Tectonic Significance of Baoraoleaobao Quartz Diorite in the Eren Nur Area of China-Mongolia Border Region
摘要
Abstract
The LA-ICP-MS zircon U-Pb dating of Baoraole'aobao quartz-diorite pluton in the Eren Nur area shows that its age is (302.5±1.1)Ma(MSWD=0.28),indicating that this pluton was formed in the late stage of Late Carboniferous Epoch,belonging to Variscan period.The lithogeochemical results suggest that the quartz-diorites in this area possess high TiO2 and A12 O3,with values Mg# of 0.46-0.50,A/CNK ratios of 0.77-0.90 and δ values of 1.54-2.53,showing the geochemical characteristics of middle-and high-K calc-alkaline series with metaluminous.REE have medium abundance and show right-dipping pattern of enriched LREE and depleted HREE,with not obvious or weakly negative Eu anomaly.The LILE (Rb,Ba and K) are enriched,while the HFSE (Nb,Ta,P and Ti) are depleted,having the geochemical characteristics of island arc magmatic rocks,suggesting that the subduction events occurred in the Baoraoleaobao area at the end of Late Carboniferous Epoch.The comparison of the regional geological data reveals that this pluton belongs to a part of Xiwuqi-Suzuoqi magmatic arc,which provides a new evidence for further studying the evolution process of Xilinhot-Suzuoqi suture zone subducted toward Suolun area in Late Carboniferous Epoch.关键词
包饶勒敖包石英闪长岩/锆石U-Pb定年/俯冲-消减/西乌旗-苏左旗弧岩浆/晚石炭世/额仁淖尔地区Key words
Baoraoleaobao quartz diorite/zircon U-Pb age/subduction/Xiwuqi-Suzuoqi magmatic arc/Late Carboniferous Epoch/Eren Nur area分类
天文与地球科学引用本文复制引用
张树栋,龙舟,张明洋,来林,洪文武,周长红,张学斌..中蒙边境额仁淖尔地区包饶勒敖包石英闪长岩锆石U-Pb年龄及构造意义[J].地质科技情报,2017,36(3):92-102,11.基金项目
中国地质调查局地质大调查项目(12120114064001) （12120114064001）
