大别山辉石岩—辉长岩体的锆石U—Pb年龄及其地质意义

大别山辉石岩—辉长岩体的锆石U—Pb年龄及其地质意义

李曙光洪吉安李惠民江来利

[1]中国科学技术大学地球与空间科学系 [2]地质矿产部天津地质矿产研究所

收稿日期:1999-09-20 修回日期:1999-09-20 出版日期:1999-09-20 发布日期:1999-09-20

U－Pb ZIRCON AGES OF THE PYROXENITE-GABBRO INTRUSIONS IN DABIE MOUNTAINS AND THEIR GEOLOGICAL IMPLICATIONS

Li Shu-guang1, Hong Jian1, Li Huimin2, Jiang Laili3

1．Department of Earth and Space Sciences，University of Science and Technology of China, Hefei 230026; 2. Tiajin Institute of Geology and mineral Resources, CAGS, Tiajin 300170; 3. Anhui Institute of Geology, No.1 Ningguo Road, Hefei 230026

Received:1999-09-20 Revised:1999-09-20 Online:1999-09-20 Published:1999-09-20

摘要/Abstract

摘要： 大别山北部祝家铺，小河口和椒岩三个辉石岩－辉长岩侵入体的锆石给出四个Ｕ－Ｐｂ谐和年龄，范围均在１２３￣１３０Ｍａ之间，这表明这些基性／超基性侵入体是碰撞后成因的。由于白垩纪花岗岩脉普遍穿切这些辉长岩体，说明大别山垩纪大规模岩浆事件，是从深部地幔部分熔融开始的，其热动力可能源于地幔上涌。

Abstract: Four U-Pb zircon ages ranging 123～130Ma for the Zhujiapu, Jiaoyan gabbro and Xiaohekou pyroxenite-gabbro intrusions in the Dabie Mountains suggest that these mafic-ultramafic intrusio11s are of the post-collisional origin and crystallized in the Cretaceous．In view of that the Cretaceous granitic dykes cut across the mafic-ultramafic intrusions, the large scale Cretaceous magmatic event in the Dabie Mountains was initiated by partial melting of the mantle in depth, which may be caused by upwelling of the mantle beneath the Dahie Mountains at that time．

李曙光洪吉安李惠民江来利. 大别山辉石岩—辉长岩体的锆石U—Pb年龄及其地质意义[J]. J4.

Li Shu-guang1, Hong Jian1, Li Huimin2, Jiang Laili3. U－Pb ZIRCON AGES OF THE PYROXENITE-GABBRO INTRUSIONS IN DABIE MOUNTAINS AND THEIR GEOLOGICAL IMPLICATIONS[J]. J4.