中文摘要：

弥渡吉祥庄火山岩和巍山大莲花山岩体是金沙江富碱岩带的重要组成部分,两者总体呈近NW向展布,受哀牢山—金沙江断裂带控制。岩石学和LA-ICP-MS锆石U-Pb同位素年代学研究表明,弥渡吉祥庄火山岩为粗面岩,巍山大莲花山岩体为石英闪长斑岩;吉祥庄火山岩LA-ICP-MS锆石U-Pb年龄为36.27±0.50 Ma,巍山大莲花山岩体LA-ICP-MS锆石U-Pb年龄为37.02±0.46Ma。弥渡吉祥庄火山岩和巍山大莲花山岩体形成时代为喜马拉雅早期,两者形成于后碰撞构造背景。

英文摘要：

The Jixiangzhuang volcanic rock at Midu and the Dalianhuashan pluton at Weishan are the major parts of the Jinshajiang alkaii-rich magmatic rock b e l t ,with both distributed along near north-west direction and controlled by the Ailaoshan-Jinshajiang fault zone. In this a r t ic le, authors investigated pe-trology and LA-ICP-MS zircon U-Pb geochronology of the rock samples collected from the Jixiangzhuang volcanic rock andDal ianhuashan p lu to n The petrographic characteristic shows th at the Jixiangzhuang vol-canic rock is trachyte and the Dalianhushan pluton is quartz-diorite-porphyry. The LA-ICP-MS zircon U-Pb dating yields a 206 Pb /238U weighted average age of 36. 27 ± 0. 50 Ma for the Jixiangzhuang volcanic rockand an age of 37. 02 ± 0. 46 Ma for the Dalianhushan pluton. It can be concluded that the Jixiangzhuang volcanic rock and Dalianhuashan pluton formed in a post-collision tectonic background in Earlperiod.