山东五莲中生代岩浆岩的锆石U—Pb年龄

山东五莲中生代岩浆岩的锆石U—Pb年龄

周建波1 2, 郑永飞2, 赵子福2

1. 吉林大学地球科学学院，长春 130026 ; 2. 中国科学技术大学地球和空间科学学院，合肥 230026

收稿日期:2003-06-20 修回日期:2003-06-20 出版日期:2003-06-20 发布日期:2003-06-20

Zircon U-Pb Dating on Mesozoic Granitoids at Wulian，Shangdong Province

ZHOU Jian-bo1 2, ZHENG Yong-fei2, ZHAO Zi-fu2

1. School of Earth Sciences, Jilin University, Changchun 130026, China; 2. School of Earth and Space Science, University of Science and Technology of China, Hefei 230026, China

Received:2003-06-20 Revised:2003-06-20 Online:2003-06-20 Published:2003-06-20

摘要/Abstract

摘要： 苏鲁造山带产出一系列中生代岩浆岩，但是对它们的确切侵位年龄至今尚无正式报道。对其西北部五莲断裂附近四个花岗质侵入岩体进行了锆石U—Pb年龄测定，结果得到大店复式岩体中角闪二长岩的谐和年龄为123±4Ma，七宝山氢式火山—侵入杂岩体中辉石二长岩的谐和年龄为126±3Ma。五莲山岩体中晶洞花岗岩的谐和年龄为116±4Ma，马耳山岩体中不等粒二长花岗岩的谐和年龄为115±1Ma。这些锆石U—Pb年龄结果说明，苏鲁造山带同样存在侵位时间分别为115Ma和125Ma左右的早白垩纪侵人体，与大别造山带内大面积出露的燕山期岩浆岩年龄基本一致，代表了扬子板块与华北板块在三叠纪碰撞折返后的岩浆活动，其物质来源可能与俯冲陆壳的部分熔融有关。

Abstract: Zircon U-Pb dating was carried out for four granitoid plutons at Wulian in the north-western part of the Sulu orogenic belt，whose intrusion ages were not known for a long time and thus were often confused with adjacent granitoids of Neoproterozoic age． The present dating yields concordant ages of 123±4 Ma for amphibole monzonite at Dadian, 126±3 Ma for pyroxene monzonite at Qibaoshan，116±4 Ma for miraolitic granite at Wulianshan．and 115±1 Ma for monzonitic granite at Maershan．The results show the occurrence of Early Cretaceous intru sions at～ 115 Ma and ～ 125 Ma in the Sulu orogenic belt，being consistent with those coeval magmatic activity in the Dabie orogenic belt an d the northeastern part of the Sulu orogenic belt．Although these Yanshanian granitoids occur in the Triassic collisional orogen between the Yangtze and North China plates，they belong to post-collisional magmatism and were produced by partial melting of the subducted continental crust．

周建波 , 郑永飞, 赵子福. 山东五莲中生代岩浆岩的锆石U—Pb年龄[J]. J4.

ZHOU Jian-bo1 2, ZHENG Yong-fei2, ZHAO Zi-fu2. Zircon U-Pb Dating on Mesozoic Granitoids at Wulian，Shangdong Province[J]. J4.