摘要
通过中国及邻近陆海地区天然地震面波层析成像三维Vs速度结构的系统地质构造解析,笔者论述了中国及邻近陆海地区软流圈三维结构特征,发现该区软流圈内既有高速块体,又有低速异常体,显示软流圈内存在纵向与横向上的不均匀性,研究软流圈内低速异常体三维几何结构表明,南海低速异常体呈复蘑菇状,结合地幔体波层析成像研究显示,南海地区存在巨型复蘑菇状地幔低速柱头。笔者还探讨了软流圈对岩石圈结构的影响及其相互作用问题。
This paper discusses the 3D structure features of the asthenosphere beneath China and adjacent land and sea areas based on a systematic tectonic analysis of the 3D velocity structure by using seismic surface wave tomographic imaging. Both high-velocity blocks and low-velocity anomalies were discovered in the asthenosphere of the region, indicating the existence of vertical and lateral heterogeneities in the asthenosphere. Study of the 3D geometric structure of the low-velocity anomalies in the asthenosphere suggests that the anomaly beneath the South China Sea asthenosphere is composite mushroom-shaped. According to this finding, combined with the mantle body wave tomographic image, it is concluded that a giant composite mushroom-shaped low-velocity mantle plume might occur at over 2000 km depth in the region. In addition, this paper approaches the problem related to the impact of the asthenosphere on the lithospheric structure and their interaction.
出处
《中国地质》
CAS
CSCD
2006年第4期804-815,共12页
Geology in China
基金
国家自然科学基金重点项目(49734150
40234047)
国土资源部重点科技专项计划项目(20001010206)联合资助。
关键词
软流圈
岩石圈
面波层析成像
构造解析
高速块体
复蘑菇状低速异常体
三维结构
中国
asthenosphere
lithosphere
surface wave tomographic image
structural analysis
high-velocity block
composite mushroom-shaped low-velocity anomaly
3D structure
China
