安徽庐枞盆地中巴家滩岩体的年代学研究及其意义  

Chronology of the Bajiatan intrusion in the Luzong basin,Anhui,and its significance.

作　　者：周涛发[1] 宋明义[1] 范裕[1] 袁峰[1] 刘珺[2] 吴明安[3] 钱存超[4] 陆三明[4] 

机构地区：[1]合肥工业大学资源与环境工程学院,合肥230009 [2]中国地质大学(北京)地球科学与资源学院,北京100083 [3]安徽省地质调查院,合肥230001 [4]安徽省地质调查与检测中心,合肥230009

出　　处：《岩石学报》2007年第10期2379-2386,共8页Acta Petrologica Sinica

基　　金：国家自然科学基金项目(编号:40672062;40272048);高等学校博士学科点科研基金项目(编号:20050359013);国家重点基础研究发展规划973项目(编号:2007CB411405);安徽省优秀青年科技基金和安徽省国土厅地质勘查专项费项目的资助。

摘　　要：安徽庐枞盆地是长江中下游地区重要的火山岩盆地,巴家滩岩体是盆地内主要的侵入岩体之一,该侵入岩的年代学研究对庐枞盆地的岩浆作用过程、时间及构造背景的确定等具有重要的意义。本次工作得到巴家滩岩体锆石SHRIMP U-Pb年龄为133.5±0.6Ma,黑云母^(40)Ar/^(39)Ar年龄为129.0±0.6Ma,表明其形成于早白垩世,岩体侵位较深且冷却速率较慢。本文认为133.5Ma的年龄可能代表庐枞盆地由早阶段挤压-拉张过渡背景向晚阶段典型拉张构造背景的转变时间。The Luzong (Lujiang-Zongyang) basin is an important volcanic basin in the middle-lower Yangtze River valley and the Bajiatan intrusion is one of the important intrusions in the basin. The chronological study of the intrusion has great significance for the determination of the processes and timing of magmatism and tectonic setting in the Luzong basin. The SHRIMP U-Pb zircon age of and biotite Ar-40/Ar-39 age of the intrusion are 133.5 +/- 0.6 Ma and 129.0 +/- 0.6 Ma respectively, suggesting an Early Cretaceous age for the formation of the intrusion. The intrusion was emplaced at a relatively deep level and cooled at a slow rate. The authors think that the age of 133.5 Ma might represent the age of transition of the Luzong basin from a compressional-extensional regime in the early stage to a typical extensional regime in the late stage.

关 键 词：辉石二长岩 巴家滩岩体 SHRIMP 庐枞盆地 安徽 

分 类 号：P588.122[天文地球—岩石学] P597.3[天文地球—地质学]