湖南骑田岭岩体东缘菜岭岩体的锆石SHRIMP定年及其意义

Zircon SHRIMP dating of the Cailing granite on the eastern margin of the Qitianling granite, Hunan, South China, and its significance

摘要: 提要：应用锆石SHRIMP方法对湖南骑田岭岩体东缘的“印支期”菜岭岩体进行了精确的SHRIMP定年研究。结果表明菜岭花岗岩的形成年龄为（160±2）Ma，从而确证它是燕山期花岗岩，且属于骑田岭岩体主侵入阶段的范畴。少量继承锆石核记录了中元古代的年龄信息，表明前寒武纪岩石可能是区内花岗岩浆熔融源区的重要组成之一。

Abstract: Abstract：The Cailing granite on the eastern margin of the Qitianling granite was precisely dated at 160±2 Ma using zircon SHRIMP, which suggests that the Cailing granite was intruded in the early Yanshanian, rather than in the Indosinian as is considered previously. A few inherited cores record Mesoproterozoic age information, which indicates that Precambrian rocks might be one of the important components in the granitic magma melting source region in the study area.