苏鲁超高压造山带海州群锆石年龄及其地质意义  

The Zircon Age of Haizhou Group in the Sulu Ultrahigh-Pressure Orogenic Belt and Its Geological Implications

作　　者：王秀丽[1] 陈福坤[1] 李秋立[1] 郭敬辉[1] 

机构地区：[1]中国科学院地质与地球物理研究所固体同位素地球化学实验室,北京100029

出　　处：《地球学报》2005年第B09期125-125,共1页Acta Geoscientica Sinica

基　　金：本文得到973项目“大陆深俯冲作用”（编号：G1999075502）;国家教育部留学回国人员科研启动基金和中国科学院地质与地球物理研究所所长基金资助.

摘　　要：大别和苏鲁超高压变质带，作为中生代华北地块和扬子地块之间大陆碰撞作用的标志产物，由不同的岩石单元以构造接触拼合而成。近年来的研究工作主要针对其超高压变质岩石单元，而其低级变质岩石单元如大别山北麓的北淮阳带、南麓的宿松带和苏鲁地区南部的海州群等的研究程度依然较低。这些低级变质岩石单元的形成时代、变质历史以及归属问题的厘定同样有助于完整地理解超高压变质带的形成和演化。本文报道海州群云母石英片岩的锆石年龄和钕同位素分析数据，提供区域对比资料，讨论分析结果隐含的地质意义。The ultrahigh pressure coUisional belt exposed in the Sulu terrane represents the eastern part of the Qinling-Dabie orogenic belt that resulted from collision of Yangtze and North China blocks in early Mesozoic. Here zircon ages are reported for the lowergrade metamorphic Haizhou Group exposed in southern Sulu. This rock group is lithologieally comparable with the Susong Group and the Hong＇an Group exposed in the southern part of Dabie area. Zircons of schist samples collected from Haizhou Group were analysed by U-Pb isotopic dilution and evaporation methods. The analytical results suggest that these zircons crystallised between 800 Ma and 780 Ma. Zircon grains underwent different extents of superimposition, but most of them still preserve oscillatory zoning of magmatic origin, as demonstrated by the internal structure shown in the cathodolumineseence images. These age results are similar to those reported for the Susong LT/HP zone in Dabie terrane.

关 键 词：锆石年龄 海州群 苏鲁超高压造山带 苏鲁超高压变质带 地质意义 超高压变质岩石 造山带 碰撞作用 扬子地块 华北地块 

分 类 号：P588.3[天文地球—岩石学] P618.510.2[天文地球—地质学]