北京大学学报(自然科学版)

塔北哈拉哈塘流纹岩的离子探针锆石U-Pb 年代学: 对塔里木溢流玄武岩主期喷发时代的约束

上官时迈1, 田伟1,李献华2, 关平1, 潘懋1, 陈咪咪1, 潘文庆3   

  1. 1. 北京大学地球与空间科学学院, 造山带与地壳演化教育部重点实验室, 北京 100871; 2. 中国科学院地质与地球物理研究所岩石圈演化国家重点实验室, 北京100029; 3. 中国石油天然气股份有限公司塔里木油田分公司勘探开发研究院, 库尔勒 841000;
  • 收稿日期:2011-01-24 出版日期:2011-05-20 发布日期:2011-05-20

SIMS Zircon U-Pb Age of a Rhyolite Layer from the Halahatang Area, Northern Tarim, NW China: Constraint on the Eruption Age of Major Pulse of Tarim Flood Basalt

SHANGGUAN Shimai1, TIAN Wei1, LI Xianhua2, GUAN Ping1, PAN Mao1, CHEN Mimi1, PAN Wenqing3   

  1. 1. Key Laboratory of Orogenic Belts and Crustal Evolution MOE; School of Earth and Space Sciences, Peking University, Beijing 100871; 2. State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijng 100029; 3. Institute of Petroleum Exploration and Development, Tarim Oilfield Company, PetroChina, Korla 841000;
  • Received:2011-01-24 Online:2011-05-20 Published:2011-05-20

摘要: 塔里木北部哈拉哈塘地区存在流纹岩覆盖于玄武岩之上的迭置关系。对上层流纹岩采用SIMS锆石U-Pb 法精确测定其年龄为 287.3 ±2.0 Ma。该年龄限定该区玄武岩的喷发时代不晚于 287 Ma,证明塔里木溢流玄武岩的主喷发期应不晚于 287 Ma,而非前人提出的大约 275 Ma。

关键词: 塔里木, 溢流玄武岩, 大火成岩省, 流纹岩, 锆石U-Pb年代学

Abstract: Seismological interpretation revealed that basalts are overlain by rhyolite in the Halahatang area, Northern Tarim, Northwest China. The overlying rhyolite is dated by SIMS zircon U-Pb method, yielding a precise concordia age of 287.3 ±2.0 Ma, which limits the latest eruption age of the underlying basalt and reveals that the eruption age of the main pulse of the Tarim flood basalt is before 287 Ma, not ~275 Ma.

Key words: Tarim, flood basalt, large igneous province (LIP), rhyolite, zircon U-Pb age

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