西天山那拉提岩群SHRIMP锆石U-Pb年龄及地质意义

摘要

新疆西天山那拉提构造带划归志留系，据岩性组合、变质变形特征、所含古生物化石及同位素测年结果，明显分为两部分，含珊瑚化石的大理岩、火山碎屑岩等浅变质岩系为上—顶志留统巴音布鲁克组；不含化石的中深变质岩为古元古界那拉提岩群。本次研究对艾肯达坂黑云斜长片麻岩、备战铁矿南侧条带状片麻岩进行锆石SHRIMP U-Pb测年，获得年龄值（945.9±4.4）Ma、（924±9）Ma，表明为Rodinia大陆聚合事件格伦维尔造山运动在本区的反映。%Xinjiang Nalati tectonic belt of Western Tianshan Mountains in the original Silurian,According to the charac-teristics of deformation,metamorphic lithology combination,the fossils and isotopic dating results, Was divided into two parts:With Coral fossils of marble、volcanic clastic rocks Belong to Upper Silurian Bayinbuluke formationThe mesometa-morphic rock without fossils belongs to the paleo Proterozoic Nalati rock group,zircon SHRIMP U-Pb Dating of biotite plagioclase gneiss in Aikendaban、banded gneiss in the South side of Beizhan iron ore results are (945.9±4.4)Ma、(924±9) Ma,Represents a Rodinia continental convergence event that Grenville orogeny reflecting in the area.