何静^1,2,,
吴庆举^2,,,
张瑞青²,
雷建设¹
1. 中国地震局地壳应力研究所(地壳动力学重点实验室), 北京 100085
2. 中国地震局地球物理研究所, 北京 100081

基金项目: 国家自然基金（41274088，41704054），中国地震局地壳应力研究所中央级公益性科研院所基本科研业务专项（ZDJ2017-01）联合资助


详细信息

作者简介: 何静, 女, 1990年生, 博士, 助理研究员, 主要从事地球深部构造及动力学方面的研究.E-mail:hejing11@163.com

通讯作者: 吴庆举, 男, 1966年生, 研究员, 博士生导师, 主要从事地震学、地球内部结构以及动力学研究.E-mail:wuqj@cea-igp.ac.cn

中图分类号: P315

收稿日期:2018-01-09
修回日期:2018-03-21
上线日期:2018-09-05

Crustal structure beneath the Abaga area of Xing'an-Mongolia Orogenic Belt using teleseismic receiver functions

HE Jing^1,2,,
WU QingJu^2,,,
ZHANG RuiQing²,
LEI JianShe¹
1. Key Laboratory of Crustal Dynamics, Institute of Crustal Dynamics, China Administration of Earthquake, Beijing 100085, China
2. Key Laboratory of Seismic Observation and Geophysical Imaging, Institute of Geophysics, China Administration of Earthquake, Beijing 100081, China


More Information

Corresponding author: WU QingJu,E-mail:wuqj@cea-igp.ac.cn

MSC: P315

--> Received Date: 09 January 2018
Revised Date: 21 March 2018
Available Online: 05 September 2018


摘要
摘要:本文利用内蒙阿巴嘎地区布设的38个宽频带地震台站记录到的远震数据，采用P波接收函数共转换点叠加方法（CCP）揭示台站下方Moho面起伏形态，并利用H-κ方法进一步得到地壳厚度和壳内平均波速比值.结果显示，研究区地壳厚度为35~44 km，均值约为40 km，西南部的鄂尔多斯盆地边缘地壳较厚，东北部的阿巴嘎火山群地区地壳显著变薄.研究区地壳平均波速比值在1.70~1.87之间，均值为1.76，其中阿巴嘎火山地区波速比值明显偏高.CCP叠加结果显示研究区Moho界面较平缓，但在缝合带附近存在明显的变化.我们推测，新生代阿巴嘎火山地区薄的地壳和高波速比值可能是由于火山活动底侵作用引起上地幔铁镁质物质侵入下地壳所致.
关键词: 兴蒙造山带/
阿巴嘎火山/
地壳结构/
接收函数

Abstract:The crustal thickness and average crustal V_p/V_s velocity ratio beneath the region of Abaga volcano are obtained by P wave receiver functions. Primary data are recorded by 38 seismic stations deployed in the Abaga area. We also apply a common conversion point stacking (CCP) approach to investigate the characteristics of Moho. Our results reveal that the local crustal thickness ranges from 35 to 44 km with an average value of 40 km. Thicker crust is found beneath the edge of Ordos basin, while thinner crust is distributed in the Abaga volcano region. The measured crustal V_p/V_s ratio varies from 1.70 to 1.87, with an average value of 1.76. High V_p/V_s ratio is found beneath the Abaga volcanic region, correlating perfectly with the Cenozoic volcanic cluster. CCP stacking results show that Moho discontinuity beneath the study area is relatively flat with some small-scale variations at the suture zones. Thin crustal thickness and high V_p/V_s ratios beneath Cenozoic Abaga volcanic region may imply the underplating by volcanic activity, resulting in the intrusion of a large amount of mafic basalts into the crust.
Key words:Xing'an-Mongolia Orogenic Belt/
Abaga volcano/
Crustal structure/
Receiver function



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