干旱区生态环境知识资源中心(Arid): 蒙古中南部地区地壳上地幔S波速度结构初步研究

Arid

	蒙古中南部地区地壳上地幔S波速度结构初步研究
其他题名	Preliminary study of S wave velocity structure of the crust and upper mantle beneath the south-central Mongolia
	侯颉 1; 余大新 1; 吴庆举 2; 管见 1
来源期刊	地球物理学进展
ISSN	1004-2903
出版年	2017
卷号	32 期号:4 页码:1432-1438
中文摘要	基于中蒙国际科技合作项目中获取的宽频带地震阵观测资料,利用提取到的周期为10 ~ 80 s的每个网格点瑞雷波相速度频散,反演得到了蒙古中南部下方地壳以及上地幔S波速度结构.结果表明: 25 km深度处S波速度分布特征受地表构造形态控制,北部杭爱-肯特山脉为明显高速异常(约3.75 ~ 3.82 km/s),中南部戈壁沙漠为低速异常(约3.55 ~ 3.65 km/s); 42 km深度处S波速度受地壳厚度影响,具有西北到东南逐渐增大的趋势,杭爱-肯特山盆下地壳相对较高的S波速(约4.1 km/s)是由盆地形成过程中拉伸作用导致盆地下地壳厚度减薄造成的; 60 ~ 100 km深度范围内S波速度呈现南北高中部低的形态,分析认为中部戈壁低速异常与该地区新生代火山活动有关,而火山活动范围纵向上由中西部向中东部逐渐变深,横向由中东部向中西部逐渐变宽;此外,中东部地区地壳的隆起可能是由于火山活动引起的地幔热流上涌造成的.
英文摘要	Based on the data from broadband seismic arrays of the China-Mongolia cooperative project,this paper used Rayleigh wave phase velocity dispersion curves at periods ranging from 10 s to 80 s,obtained the S wave velocity structure of the crust and upper mantle beneath the south-central Mongolia. The results show that the characteristics of S wave velocity distribution in the depth of 25 km are controlled by structural form on the surface. And Hangay-Hentiy Basin in the north is associated with obvious high velocity anomaly in the range of 3.75 ~ 3.82 km/s,Gobi desert in the south is represented as low velocity anomaly in the range of 3.55 ~ 3.65 km/s. In the depth of 42 km,S wave velocity is affected by the thickness of the crust,which has a trend of gradually increasing from northwest to southeast. The relatively high S wave velocity (about 4.1 km/s) of the lower crust in Hangay-Hentiy Basin is caused by thickness reduction in lower crustal thickness which resulting by stretching action during the Basin formation process. In the range of 60 ~ 100 km depth,S wave velocity is high in the Northern and Southern,and low in central region. Analysts believe that the low velocity anomaly in the central Gobi is related to the Cenozoic volcanic activity in this region. The range of volcanic activity becomes deeper gradually from the Midwest to the Mideast in the longitudinal direction,and wider from the Mideast to the Midwest in the lateral direction. The volcanic activity in the Mideast regions leads to the heat flow of mantle upwelled and caused the middle and lower crust uplift.
中文关键词	蒙古中南部 ; 瑞雷波 ; S波速度结构 ; 地壳 ; 上地幔
英文关键词	south-central Mongolia Rayleigh wave S wave velocity structure crust upper mantle
语种	中文
国家	中国
收录类别	CSCD
WOS类目	GEOLOGY
WOS研究方向	Geology
CSCD记录号	CSCD:6065449
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/235795
作者单位	1.中国地震局第一监测中心, 天津 300180, 中国; 2.中国地震局地球物理研究所, 北京 100081, 中国
推荐引用方式 GB/T 7714	侯颉,余大新,吴庆举,等. 蒙古中南部地区地壳上地幔S波速度结构初步研究[J],2017,32(4):1432-1438.
APA	侯颉,余大新,吴庆举,&管见.(2017).蒙古中南部地区地壳上地幔S波速度结构初步研究.地球物理学进展,32(4),1432-1438.
MLA	侯颉,et al."蒙古中南部地区地壳上地幔S波速度结构初步研究".地球物理学进展 32.4(2017):1432-1438.