大别造山带北部石竹河片麻岩的锆石U-Pb年龄及其地质意义  

Zircon U-Pb dating of gneiss from Shizhuhe in North Dabie and its geologic implications.

作　　者：谢智[1] 陈江峰[1] 张巽[1] 高天山[2] 戴圣潜[2] 周泰禧[1] 李惠民[3] 

机构地区：[1]中国科学技术大学地球和空间科学系化学地球动力学研究实验室,合肥230026 [2]安徽省地质调查院,合肥230001 [3]天津地质矿产研究所,天津300170

出　　处：《岩石学报》2001年第1期139-144,共6页Acta Petrologica Sinica

基　　金：国家自然科学基金 ( No.497940 42 );前地矿部重大基础项目 ( No.95 110 2 -3-2 )

摘　　要：大别造山带北部石竹河二长片麻岩的锆石 U- Pb年龄测定结果表明 ,其原岩形成时代为 70 7± 42 Ma,在 2 2 9±18Ma曾受到高温变质作用。这一结果表明印支期变质作用不仅反映在大别造山带南部的变质岩中 ,而且造山带北部的部分变质岩也保存了这一重要记录。大别造山带北部存在印支期变质年龄的片麻岩、榴辉岩或残留相表明 ,该地块与造山带南部一样是印支期板块俯冲碰撞中俯冲板块的一部分。The zircon U Pb age of a monzogneiss from Shizhuhe in North Dabie was dated. The results indicate that the protolith of the gneiss was formed at 707±42Ma, and the rock underwent metamorphism at 229±18Ma. The ages suggest that the Indosinian metamorphism of the Dabie orogen affected not only the metamorphic rocks in South Dabie, and also some rocks in North Dabie. The gneiss with Indosinian metamorphic age, the occurrence of eclogites and eclogite facies relics in North Dabie suggest that North Dabie was a part of the subducted block as the South Dabie. The suture line between North China Block and Yangtze Block may be in the north of Dabie orogen.

关 键 词：片麻岩 锆石U-PB定年 超高压变质 印支期 大别造山带 变质作用 板块俯冲 

分 类 号：P588.345[天文地球—岩石学] P597.3[天文地球—地质学]