河南商城地区岩墙的锆石SHRIMP U-Pb年龄及其地质意义  

Zircon SHRIMP U-Pb Dating and Its Geological Significance of Dikes in Shangcheng Area,Henan Province,Central China

作　　者：王团华[1] 毛景文[1] 谢桂青[1] 

机构地区：[1]中国地质科学院矿产资源研究所,北京100037

出　　处：《矿物岩石地球化学通报》2008年第4期369-377,共9页Bulletin of Mineralogy, Petrology and Geochemistry

基　　金：国家自然科学基金重点项目(40434011);中国地质科学院矿产资源研究所科研业务专项基金项目(K0734)

摘　　要：对侵位于河南省商城县白垩纪商城花岗岩体中的岩墙进行的锆石SHRIMPU-Pb法年代学研究表明,单颗粒锆石的年龄数据反映出中-新太古代(2843Ma)、中元古代(1886Ma、1829Ma)、新元古代(768.4～535.1Ma)、古生代(353.7Ma、262.2Ma)和中生代(234.2～117.8Ma)的年龄,与区域构造事件和地质演化历史有很好的对应性。结合前人对大别造山带各类岩石年代学研究的结果,笔者认为岩墙锆石测年给出的谐和年龄751.3±39.9Ma代表大别造山带中元古代晋宁期一期重要且强度很高的变质作用年代。根据前人对大别造山带大地构造演化历史的认识,结合本文岩墙年代学研究结果,笔者认为岩墙锆石测年结果可能印证了秦岭-大别造山带中生代以来的、以岩石圈基底拆沉作用为基本特征的强烈壳幔相互作用。The SHRIMP U-Pb age data of zircon in the intruding dyke in the Cretaceous granite rocks at Shangcheng, Henan showed that the ages of individual zircons reflected the ages of Mesoneoarchean （2843 Ma）, Meso-proterozoic （1886 Ma, 1829 Ma）, Neoproterozoic （768.4-535.1 Ma）, Paleozoic （353.7 Ma, 262.2 Ma） and Mesozoic （234.2-117.8 Ma）, and these zircon ages were well correlated with regional tectonic and geological evolution events. Compared with literature chronology results of various types of rocks in Dabie orogenic belts, the author proposed that the harmonic age of 751.3 Ma 土 39.9Ma represented an important and metamorphic process intensive period in Dabie orogenic area. Combined previous studies of tectonic evolution in Dabie orogenic area with the age data of zircon in the dyke of this study, the author believed that the age data obtained in this study could have confirmed that the interaction between crust and mantle in the Qinling and Dabie orogenic area since Mesozoic time can be essentially categorized as lithosphere basement delamination.

关 键 词：岩墙 SHRIMP U-PB年代学 大别造山带 岩石圈基底拆沉作用 河南商城 

分 类 号：P597.3[天文地球—地球化学]