李雪垒^1,2,,
郝天珧^3,4,5,,,
李志伟¹
1. 中国科学院测量与地球物理研究所大地测量与地球动力学国家重点实验室, 武汉 430077
2. 湖南工商大学数学与统计学院, 长沙 410205
3. 中国科学院地质与地球物理研究所, 中国科学院油气资源研究重点实验室, 北京 100029
4. 国家海洋局海底科学重点实验室, 杭州 310012
5. 中国科学院大学, 北京 100049

基金项目: 自然资源部"全球变化与海气相互作用"专项国际合作项目(GASI-GEOGE-01), 国家自然科学基金联合基金项目(U1505232), 国家自然科学基金重点研发计划"西太平洋地球科学系统多圈层相互作用"项目(91858212), 中国东盟海洋地学研究与减灾防灾倡议项目(121201002000150022)共同资助


详细信息

作者简介: 李雪垒, 男, 1989年生, 博士后, 主要从事地壳上地幔结构研究.E-mail:seisnow@163.com

通讯作者: 郝天珧, 女, 1957年生, 研究员, 主要从事海、陆油气盆地综合地球物理研究.E-mail:tyhao@mail.iggcas.ac.cn

中图分类号: P315

收稿日期:2019-09-09
修回日期:2019-12-12
上线日期:2020-05-05

P wave velocity structure and tectonic analysis beneath southeastern China

LI XueLei^1,2,,
HAO TianYao^3,4,5,,,
LI ZhiWei¹
1. State Key Laboratory of Geodesy and Earth's Dynamics, Institute of Geodesy and Geophysics, Chinese Academy of Sciences, Wuhan 430077, China
2. School of Mathematics and Statistics, Hunan University of Technology and Business, Changsha 410205, China
3. Key Laboratory of Petroleum Resources Research, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
4. Key Laboratory of Submarine Geosciences, State Oceanic Administration, Hangzhou 310012, China
5. University of Chinese Academy of Sciences, Beijing 100049, China


More Information

Corresponding author: HAO TianYao,E-mail:tyhao@mail.iggcas.ac.cn

MSC: P315

--> Received Date: 09 September 2019
Revised Date: 12 December 2019
Available Online: 05 May 2020


摘要
摘要:利用中国东南部地震台站的波形数据，通过远震P波层析成像方法反演了福建及台湾地区的上地幔P波速度结构，据此分析了华夏块体的构造属性并探讨了中国东南部上地幔的深部动力学机制.结果表明，研究区上地幔速度结构存在明显的横向非均匀性，它们与区域构造的深部动力学成因密切相关.宏观上，NE向展布的低速异常与东南沿海地区中新生代火成岩的条带状分布保持了较好的一致性，推测其上地幔可能存在幔源物质上涌；以政和—大埔断裂带为界，东、西华夏块体的速度结构存在差异，结合前人的研究结果分析，东、西华夏块体岩石圈减薄和中新生代岩浆活动的驱动机制有所不同，西华夏块体为"板块俯冲+岩浆底侵（岩石圈拆沉）"的动力学模式，东华夏块体是"玄武质岩浆迁移+岩浆底侵"的动力学模式.
关键词: 中国东南部/
华夏块体/
层析成像/
速度结构/
岩浆活动

Abstract:Using waveform data of seismic stations in southeastern China, we employed the teleseismic P wave tomography method to invert the upper mantle P wave velocity structure beneath the Fujian-Taiwan region. Based on these results, we analyzed tectonic properties of the Cathaysia block and discussed deep dynamic mechanism of the upper mantle in southeastern China. The results show that the upper mantle velocity structure in this region is obviously lateral heterogeneity, which is closely related to deep dynamic conditions of its tectonic. Macroscopically seeing, the NE distribution of the low velocity structure is consist with the zonal distribution of Mesozoic-Cenozoic igneous rocks in coastal areas of southeastern China, and we speculate that mantle upwelling may occur beneath this region. The difference of velocity structures between the East and West Cathaysia blocks is observed in this study. Based on the former research, we suggest that the triggering mechanism is different for lithospheric thinning and Mesozoic-Cenozoic magmatic activities between them, the West Cathaysia block corresponding to the dynamic model "slab subduction + magma invasion (lithosphere delamination)" and the East Cathaysia block harmonizing with another dynamic model "migration of basaltic magma +magma invasion".
Key words:Southeastern China/
Cathaysia block/
Tomography/
Velocity structure/
Magmatic activity



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