摘要
对北秦岭地体秦岭岩群(杂岩)中的伟晶岩脉内的锆石进行了阴极发光和U-Pb年代学研究。结果表明:由于伟晶岩中的(蛤质)锆石发生蜕晶化作用或重结晶作用,U-Th体系发生了改变,其锆石阴极发光图像呈黑色,无明显环带;对4条伟晶岩脉中的蜕晶质化锆石进行的LA-ICP-MS定年显示,由于受蜕晶质化(蛤质)锆石内部Pb元素丢失的影响,其年龄多较为分散,可信度不高。只有1个样品(QL1434-1)显示了较好的谐和性,指示该伟晶岩脉的形成年龄约为380 Ma,归于晚古生代早期。
This study introduces zircon U- Pb ages for the pegmatite veins from the Qinling Group( Complex)in the Northern Qinling Belt. It presents Cathodoluminescence( CL) images for the metamict zircons in the pegmatites from the North Qinling Terrane,and suggests that the structure of zircons in the pegmatites has changed after metamictization or recrystallization,and the CL images for zircons show black color with no zone belt. The LA-ICP-MS data of the metamict zircons for four pegmatite veins show obvious Pb loss with unconcentrated ages as a result of metamictization. One sample( QL1434-1) shows concordant age of 380 Ma( Late Eopaleozoic),which is considered as the formation age of the pegmatite vein.
出处
《桂林理工大学学报》
CAS
北大核心
2015年第4期675-685,共11页
Journal of Guilin University of Technology
基金
国家自然科学基金项目(41302155
41562005)
广西自然科学基金项目(2014GXNSFBA118220
2014GXNSFBA118218)
南京大学开放基金项目(20-15-03)
广西"八桂学者"创新团队项目(2013
有色金属成矿理论与勘查技术)