江西相山火山—侵入杂岩及中基性脉岩形成时代研究  

Formation Age of the Intermediate-basic Dikes and Volcanic—Intrusive Complex in Xiangshan, Jiangxi Province

作　　者：范洪海 王德滋[2] 沈渭洲[2] 刘昌实[2] 汪相[2] 凌洪飞[2] 

机构地区：[1]核工业北京地质研究院,100029 [2]南京大学地球科学系,210093

出　　处：《地质论评》2005年第1期86-91,共6页Geological Review

基　　金："973"项目 (编号 G19990 43 2 11);国家自然科学基金重点项目 (编号 40 13 2 0 10 );南京大学成矿作用国家重点实验室开放基金资助成果

摘　　要：单颗粒锆石 U - Pb同位素定年结果表明 ,在相山西部 (尤其是邹家山矿床 )两火山旋回的界面之间 ,存在另一类潜火山岩的侵位 ,其形成年龄为 136 .0± 2 .6 Ma,岩性为潜流纹英安斑岩 ;相山火山—侵入杂岩中心相碎斑熔岩中的花岗质“团块”属潜火山岩 ,其形成年龄为 134.2± 1.9Ma。火山期后的潜石英二长斑岩及煌斑岩脉的形成年龄分别为 12 9.5± 2 .0 Ma及 12 5 .1± 3.1Ma,从而揭示相山地区的伸展、裂解作用从早白垩世就开始了 ,明显早于浙。U-Pb isotopic dating of single-grain zircons indicates that there is another emplacement event of subvolcanic rhyodacitic porphyry with an age of 136.0±2.6 Ma in the contact zone of the two volcanic cycles in the western part of the Xiangshan complex. Granitic lumps in the central-facies porphyroclastic lava belong to subvolcanic rocks with a formation age of 134.2±1.9 Ma. The U-Pb ages of the postvolcanic secondary quartz-monzonite porphyry and lamprophyre veins are 129.5±2.0 Ma and 125.1±3.1 Ma, respectively. This suggests that the extension and splitting in the Xiangshan region began in K 1, which are obviously earlier than those in the coastal regions of Zhejiang and Fujian provinces.

关 键 词：侵入杂岩 中基性脉岩 形成时代 江西 形成年龄 潜火山岩 同位素定年 单颗粒锆石 火山旋回 英安斑岩 碎斑熔岩 煌斑岩脉 相山地区 早白垩世 裂解作用 沿海地区 花岗质 矿床 侵位 岩性 石英 伸展 

分 类 号：P588.1[天文地球—岩石学] P597.3[天文地球—地质学]