湘南骑田岭竹枧水花岗岩的锆石SHRIMPU-Pb年代学和岩石学  

Zircon SHRIMP U-Pb Geochronology,Petrology and Geochemistry of the Zhujianshui Granite,Qitianling Pluton,Southern Hunan Province

作　　者：朱金初[1] 张辉[2] 谢才富[1] 张佩华[1] 杨策[1] 

机构地区：[1]内生金属矿床成矿机制研究国家重点实验室,南京大学南京210093 [2]中国科学院地球化学研究所,贵阳550002

出　　处：《高校地质学报》2005年第3期335-342,共8页Geological Journal of China Universities

基　　金：国家自然科学基金(40373014;40132010;40073008)

摘　　要：骑田岭岩体的竹枧水花岗岩是我国南岭地区最早进行同位素年龄测定的花岗岩之一,20世纪60年代初期获得的黑云母K-Ar年龄数据,曾用来作为骑田岭花岗岩属于印支期的主要依据。最近对其进行了锆石SHRIMPU-Pb年龄测定及岩石学和地球化学研究,测得其结晶年龄为160±2Ma,属燕山早期。它富碱富钾,富含LILE和HFSE,具壳幔混合来源,形成于华南大陆内部后造山阶段拉张减薄的构造环境。The Zhujianshui granite of Qitianling pluton is one of the granites whose emplacement age was determined isotopically by biotite K-Ar method during the early 1960＇s. Since then the Qitianling granitic pluton was considered to be Indosinian （Triassic） for many years. This paper studies the zircon SHRIMP U-Pb geochronology, petrology and geochemistry of the Zhujianshui granite, Qitianling pluton. An emplacement age of 160 ± 2 Ma was obtained which indicates an early Yanshanian （Jurassic） magmatic activity. The Zhujianshui granite is enriched in alkalies （ especially in K）, LILE＇s and HFSE＇s, and has a mantle-crustal mixed source. It was formed under a postorogenic extensional environment within the South China continent.

关 键 词：骑田岭花岗岩 锆石SHRIMP U—Pb定年 岩石学 地球化学 后造山拉张构造环境 

分 类 号：P597[天文地球—地球化学] P588.121[天文地球—地质学]