地学前缘 ›› 2023, Vol. 30 ›› Issue (5): 358-368.DOI: 10.13745/j.esf.sf.2023.7.16

• “印度欧亚大陆碰撞及其远程效应”专栏之九 • 上一篇    下一篇

RF-RTM成像方法研究新疆西准噶尔地区线性台阵下方地壳结构

姜小欢1,2(), 黄荣3,4,*(), 朱露培5, 卢占武6, 罗银河3,4, 张荣堂1, 徐浩1   

  1. 1.武汉轻工大学 土木工程与建筑学院, 湖北 武汉 430023
    2.中国科学院 精密测量科学与技术创新研究院 大地测量与地球动力学国家重点实验室, 湖北 武汉 430077
    3.中国地质大学(武汉) 地球物理与空间信息学院, 湖北 武汉 430074
    4.中国地质大学(武汉) 地质过程与矿产资源国家重点实验室, 湖北 武汉 430074
    5.美国圣路易大学 地球与大气科学系, 美国圣路易斯 63108
    6.中国地质科学院 地质研究所, 北京 100037
  • 收稿日期:2023-07-08 修回日期:2023-07-12 出版日期:2023-09-25 发布日期:2023-10-20
  • 通讯作者: 黄荣
  • 作者简介:姜小欢(1989—),女,博士,讲师,主要从事远震接收函数成像研究。E-mail: xhjiang@whpu.edu.cn
  • 基金资助:
    大地测量与地球动力学国家重点实验室2022年基金项目(SKLGED2022-4-2);自然资源部深地科学与探测技术实验室开放课题(202206);地质过程与矿产资源国家重点实验室科技部专项(MSFGPMR2022-4);武汉轻工大学引进人才科研启动资金项目(2022RZ015);湖北巴东地质灾害国家野外科学观测研究站开放基金项目(BNORSG-202214)

Crustal structure beneath a seismic linear array in the Western Junggar, northwestern China by RF-RTM imaging

JIANG Xiaohuan1,2(), HUANG Rong3,4,*(), ZHU Lupei5, LU Zhanwu6, LUO Yinhe3,4, ZHANG Rongtang1, XU Hao1   

  1. 1. School of Civil Engineering and Architecture, Wuhan Polytechnic University, Wuhan 430023, China
    2. State Key Laboratory of Geodesy and Earth’s Dynamics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430077, China
    3. School of Geophysics and Geomatics, China University of Geosciences (Wuhan), Wuhan 430074, China
    4. State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences (Wuhan), Wuhan 430074, China
    5. Department of Earth and Atmospheric Sciences, Saint Louis University, St. Louis, MO 63108, USA
    6. Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China
  • Received:2023-07-08 Revised:2023-07-12 Online:2023-09-25 Published:2023-10-20
  • Contact: HUANG Rong

摘要:

本文基于2017年7月8日至2017年8月2日在西准噶尔地区布设的一条100 km的线性台阵,从记录的三分量波形数据中计算出P波接收函数,采用接收函数逆时偏移(RF-RTM)方法获得了台阵下方地壳结构成像结果。结果表明测线下方扎伊尔山和准噶尔盆地结构差异较大:扎伊尔山下Moho界面平均深度为42 km,横向连续且起伏较小;准噶尔盆地下方地壳结构成像结果较复杂,盆地基底延伸至3 km深,盆地下方Moho界面沿着测线走向(北西-南东)深度逐渐加深,在测线最南东端达到50 km;另外,在准噶尔盆地下方35 km深处可看出一明显的速度异常界面,推测可能是由古生代大洋岩石圈残片造成。上述研究成果有助于加深对西准噶尔地区的大陆岩石圈形成和演化过程的理解。

关键词: 接收函数, 逆时偏移, 密集台阵, 西准噶尔, 地壳结构

Abstract:

Data used in this paper were obtained from a 100-km long linear seismic array, Western Junggar area, by continuous recording from July 08 to August 02, 2017. We first calculate teleseismic P-wave receiver functions and then apply reverse time migration of teleseismic receiver function (RF-RTM) method to image the Moho variations beneath the linear array. The results show obvious differences in the crustal structure beneath the Zaire Mount and the Junggar Basin. The Moho discontinuity beneath the Zaire Mount flattens to a depth of ~42 km; while the crustal structure beneath the Junggar Basin appears quite complex. The basement of the Junggar Basin extends to a depth of 3 km, and the Moho discontinuity gradually deepens along the trend of the linear array from northwest (NW) to southeast (SE), finally reaching to a depth of 50 km. We also observe especially an obvious velocity anomaly interface at a depth of about 35 km, and infer that it might be generated by a Paleozoic fossil oceanic subducting slab. Our study may shed light on the formation and evolution of continental lithosphere in the Western Junggar area.

Key words: receiver function, reverse time migration, seismic dense array, Western Junggar, crustal structure

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