摘要
对依兰地区黑龙江混杂岩中的变玄武岩、变枕状玄武岩及变堆晶辉长岩岩块中的锆石进行了LA-ICP-MS U-Pb同位素测定,结果表明,变玄武岩的锆石大量为捕获基底的锆石,其年龄范围大,从3172±24Ma到176±1Ma均有分布,其中具有基性岩典型的板状特征的锆石年龄为243±1Ma,代表了变玄武岩的原岩形成年龄;变枕状玄武岩及变堆晶辉长岩的年龄分别为251±1Ma和252±1Ma,分别代表各自原岩的形成年龄。本次锆石年龄的获得,证明晚二叠世佳木斯地块和松嫩-张广才岭地块之间存在古洋盆,为研究黑龙江杂岩的演化历史提供了重要的年代学依据。
In this study, LA-ICP-MS zircon U-Pb method was used to study the geochronology of metamorphic basalt, metamor？phic pillow basalt and metamorphic accumulated gabbro of Heilongjiang complex in Yilan area. The results obtained demonstratethat many zircons in metamorphic basalt originated from basal rocks and their distribution of ages are wide, with their geochronologi？cal ages varying between 3172±24Ma and 176±1Ma. The age of plane textural zircon is 243Ma, which represents the original rockformation age of the metamorphic basalt. Concordant ages of the metamorphic pillow basalt and metamorphic accumulated gabbroare 251±1Ma and 252±1Ma respectively, which represent the formation ages of their original rock. Zircon U-Pb geochronologicalresults demonstrate that an ancient oceanic basin existed between Jiamusi block and Songnen-Zhangguangcailing block during LatePermian. The results obtained by the authors provide important geochronological evidence for studying the tectonic evolution of theHeilongjiang complex.
出处
《地质通报》
CAS
CSCD
北大核心
2016年第7期1081-1094,共14页
Geological Bulletin of China
基金
中国地质调查局项目(编号:1212011121006)
