| 西藏羌塘地体南缘改则嘎布扎花岗闪长岩侵位时代、成因及其地质意义 |
| |
| 引用本文： | 秦 川 李智武 朱利东 张玉修,杨文光 黄 瑞.西藏羌塘地体南缘改则嘎布扎花岗闪长岩侵位时代、成因及其地质意义[J].中国地质,2015(1):105-117. |
| |
| 作者姓名： | 秦 川 李智武 朱利东 张玉修 杨文光 黄 瑞 |
| |
| 作者单位： | 1. 成都理工大学油气藏地质及开发工程国家重点实验室, 四川 成都 610059; 2. 中国科学院计算地球动力学重点实验室, 北京 100049; 3. 中国科学院大学地球科学学院, 北京 100049 |
| |
| 基金项目： | 中国地质调查项目(1212011086065)和国家自然科学基金项目(40802048, 41472209，41002055)及高等学校博士学科点专项科研基金（20125122110010）联合资助。 |
| |
| 摘 要： | 改则地区的嘎布扎花岗闪长岩侵入于南羌塘地体南缘的侏罗系色哇组,为研究班公湖—怒江缝合带的演化提供新的约束。岩浆锆石的LA-ICP-MS U-Pb年龄为(143.8±0.5)Ma,显示花岗闪长岩的侵位时代为晚侏罗世—早白垩世之交。花岗闪长岩具有准铝质I型花岗岩的特点,属于高钾钙碱性岩石系列;稀土元素为轻稀土富集型,存在弱的Eu负异常;明显富集Rb、Ba、K、Th、U等大离子亲石元素,而亏损Nb、Ta、P、Ti等高场强元素。研究表明花岗闪长岩的岩浆源区可能经历了陆壳物质、俯冲沉积物与幔源楔等不同性质的岩浆混合,并经历一定程度的分离结晶作用形成。改则嘎布扎花岗闪长岩形成于班公湖—怒江中特提斯洋晚侏罗世—早白垩世向北俯冲的岛弧环境。
|
| 关 键 词： | 花岗闪长岩 锆石U?Pb年龄 俯冲 岛弧 班公湖—怒江缝合带 |
The emplacement epoch, petrogenesis and geological significance of Gabuzha granodiorite at the southern edge of Qiangtang, Tibet |
| |
| QIN Chuan,LI Zhi-wu,ZHU Li-dong,ZHANG Yu-xiu,YANG Wen-guang,HUANG Rui.The emplacement epoch, petrogenesis and geological significance of Gabuzha granodiorite at the southern edge of Qiangtang, Tibet[J].Chinese Geology,2015(1):105-117. |
| |
| Authors: | QIN Chuan LI Zhi-wu ZHU Li-dong ZHANG Yu-xiu YANG Wen-guang HUANG Rui |
| |
| Affiliation: | 1. Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu 610059, Sichuan, China; 2. Key Laboratory of Computational Geodynamics, CAS, Beijing 100049, China; 3. College of Earth Science, University of Chinese Academy of Sciences, Beijing 100049, China |
| |
| Abstract: | Abstract: The Gabuzha granodiorite in Gerze area intruded into the Jurassic Sewa Formation at the southern edge of the southern Qiangtang terrane, and can be used to constrain the evolution of Bangong Co-Nujiang River suture zone. LA-ICP MS zircon U-Pb dating yielded a weighted mean age of (143.8±0.5) Ma, suggesting that the Gabuzha granodiorite formed during late Jurassic to early Cretaceous. The Gabuzha granodiorite is metaluminous I-type granite and belongs to high-K calc-alkaline series. Its REE model is characterized by enrichment of light REE, and Eu shows weak negative anomaly. Large ion lithophile elements are obviously enriched in Rb, Ba, K, Th and U. High field strength elements Nb, Ta, P and Ti show strong depletion. The results show that the magma source of Gabuzha granodiorite might have been derived from mixture of continental crust materials, subducting sediments and mantle-derived wedge, and experienced a certain degree of separation and crystallization as well. The Gabuzha granodiorite formed in an island arc environment related to northward subduction of the Bangong Co-Nujiang River Meso-Tethys Ocean beneath the Qiangtang terrane. |
| |
| Keywords: | granodiorite zircon U-Pb age subduction island arc Bangong Co-Nujiang River suture zone |
| 本文献已被 CNKI 等数据库收录！ |
| 点击此处可从《中国地质》浏览原始摘要信息 |
|
点击此处可从《中国地质》下载全文 |
|
