西沙海域上新世以来火山特征及其形成机制*
作者简介:冯英辞(1988—), 男, 在读博士研究生, 从事海洋新构造与地质灾害研究。E-mail: ycfeng@scsio.ac.cn
收稿日期: 2016-08-30
要求修回日期: 2016-10-31
网络出版日期: 2017-06-01
基金资助
国家重点基础研究发展计划项目(2013CB956104)
国家自然科学基金项目(41376063)
The formation mechanism and characteristics of volcanoes in the Xisha waters since Pliocene
Received date: 2016-08-30
Request revised date: 2016-10-31
Online published: 2017-06-01
Supported by
National Program on Key Basic Research Project of China (2013CB956104)
National Natural Science Foundation of China (41376063)
Copyright
冯英辞 , 詹文欢 , 孙杰 , 姚衍桃 , 郭磊 , 陈梅 . 西沙海域上新世以来火山特征及其形成机制*[J]. 热带海洋学报, 2017 , 36(3) : 73 -79 . DOI: 10.11978/2016080
Due to data sparsity, volcanic activity in the Xisha waters is poorly understood. Single channel seismic profiles are used to study the volcanoes’ structures and their formation mechanisms in this paper. Seismic profiles document 10 submarine volcanoes in the south XW. Inside the volcanoes, discontinuous but strong reflections are observed and interpreted as lava flows. In addition, seismic data show two isolated volcanoes intruding Quaternary strata in the western edge and middle XW, respectively. Stratigraphic contact relationship between the lava flows and surrounding sedimentary strata reveals that Pliocene and Quaternary are two main magmatic activity stages in the XW. We propose the formation mechanism of volcanoes in the XW be that upwelling mantle magma weakens mantle lithosphere, migrates along pre-existing fault, and then erupts to the palaeo-seabed.
Fig. 1 Tectonic map of Xisha waters图1 西沙海域地形和构造简图^1970年以来海域天然地震据《中国地震台网地震目录》; 研究区5.5Ma以来岩浆岩分布(张峤 等, 2014); 研究区断裂分布(高战朝, 1986; 杨胜雄 等, 2015); 黑色实线和虚线为研究区单道地震测线位置; X1、X2、A、B、C为地震测线名; M4.9等为天然地震震级 |
Fig. 2 Volcanoes in single-channel seismic profiles across the Xisha waters (see Line A in |
Fig. 3 Single-channel seismic profiles across the study area (see Lines X1 and X2 in |
Fig. 4 Single volcano in single-channel seismic profiles (see Line B and C in |
The authors have declared that no competing interests exist.
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