摘要
纳赤台群是东昆仑早古生代造山带中岩石组成复杂的重要岩石地层单位,长期以来对其形成时代存在较大分歧。采用SHRIMP锆石U-Pb定年方法,对格尔木南水泥厂地区出露的纳赤台群石灰厂组流纹岩进行了高精度年代测定,结果表明,流纹岩中13个岩浆岩锆石206Pb/238U年龄平均值为450.4±4.3 Ma,它被解释为火山作用年龄,由此限定纳赤台群石灰厂组火山岩段形成时代为晚奥陶世。
The Naij Tal Group is a major lithostratigraphic unit with a complex composition in the East Kunlu Paleozoic orogenic belt,and there has long been debate on its formation time.The An average SHRIMP zircon 206Pb /238U age of 450.4 ± 4.3 Ma has been obtained for 15 rhyolite samples collected from the Shihuichang Formation of the Naij Tal Group south of Gelmud.It was interpreted as the age of a volcanic activity,so the Shihuichang Formation of the Naij Tal Group can be considered to form in the Late Ordovician.
出处
《地质力学学报》
CSCD
2010年第1期21-27,50,共8页
Journal of Geomechanics
基金
中国地质调查局地质调查项目(1212010711510)资助
