| 利用接收函数方法研究中国东北东南部地区不同构造体的地壳特征 |
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| 引用本文： | 李天觉,陈棋福.利用接收函数方法研究中国东北东南部地区不同构造体的地壳特征[J].地球物理学报,2019,62(8):2899-2917. |
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| 作者姓名： | 李天觉 陈棋福 |
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| 作者单位： | 1. 中国科学院地质与地球物理研究所, 中国科学院地球与行星物理重点实验室, 北京 100029;2. 中国科学院地球科学研究院, 北京 100029;3. 中国科学院大学地球与行星物理学院, 北京 100049 |
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| 基金项目： | 国家自然科学基金项目（41474041和41774058）资助. |
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| 摘 要： | 基于我们布设的探测深俯冲的中国东北地震台阵NECsaids台阵和固定地震台长时段的观测记录及NECESSArray流动台阵共计152个台站数据提取得到的33752条P波接收函数，采用H-κ叠加分析和共转换点（CCP）叠加成像等方法进行统一分析处理，并汇集他人接收函数研究结果得到中国东北东南部地区迄今为止最高分辨率的地壳厚度和平均波速比分布图像.对中国东北东南部地区不同构造体的地壳特征综合分析研究表明：研究区不同陆块的地壳属性存在明显差别，张广才岭地块中南部的地壳厚度和波速比与华北克拉通东北缘相当，地壳厚度同地表地形之间显示有明显的正相关关系；松辽地块东南缘地壳最薄、波速比最高，地壳厚度同壳内波速比之间显示出明显的负相关关系；兴凯地块西部地区的地壳结构表现为稍厚的地壳厚度和研究区内最低的壳内波速比，其地壳厚度同壳内波速比之间亦显示出明显的负相关关系；佳木斯地块西南缘在具有"正常"的壳内波速比同时地壳最厚.研究区内的郯庐断裂带北延段在切穿其下Moho面的同时表现出南北分段的特征：北段（44.4°N—47°N）两分支之下的Moho面整体下凹，而南段（41.5°N—43.3°N）两分支之下的Moho面则整体上隆.长白山天池火山下方表现为Moho面下凹沉落及高壳内波速比特征，推测其壳内岩浆囊很可能存在于火山口东北隅至少10 km的范围内.
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| 关 键 词： | 中国东北 接收函数 Moho面 波速比 郯庐断裂带北延 长白山天池火山 |
| 收稿时间： | 2018-10-19 |
Crustal structure of different tectonic units in southeastern part of Northeast China using receiver functions |
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| LI TianJue,CHEN QiFu.Crustal structure of different tectonic units in southeastern part of Northeast China using receiver functions[J].Chinese Journal of Geophysics,2019,62(8):2899-2917. |
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| Authors: | LI TianJue CHEN QiFu |
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| Institution: | 1. Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China;2. Institutions of Earth Science, Chinese Academy of Sciences, Beijing 100029, China;3. College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China |
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| Abstract: | Based on our broadband seismological records named NECsaids (NorthEast China Seismic Array to Investigate Deep Subduction) that deployed in NE China from July 2010 to May 2017, as well as the permanent seismological records operated by China Earthquake Administration (CEA) from August 2007 to May 2017 and seismological records from the international collaborative project named NECESSArray (NorthEast China Extended Seismic Array) from September 2009 to August 2011, we acquired 33752 P-wave receiver functions (RFs) in total with high quality. And then using H-κ stacking technique and common converted points (CCP) stacking technique, we obtained the highest-resolution crustal structure in southeastern part of NE China so far as we know, which consists of 231 measurements of crustal thickness and VP/VS ratio (including 89 measurements from former studies) and 3 CCP stacking profiles. The main results in this study are summarized as follow:
The five micro-continental blocks in our study region show different crustal structure distinctly. The south-central part of the Zhangguangcai Ranges owns the similar crustal thickness and VP/VS ratio as the northeastern part of the North China Craton. The southeastern part of the Songliao Block has the thinnest crust and highest crustal VP/VS ratio. As for the western Khanka Block, it keeps a slightly thicker crustal thickness while with the lowest crustal VP/VS ratio. The southwestern part of the Jiamusi Massif owns an ordinary crustal VP/VS ratio but its crust is the thickest. The important tectonic line like the Tanlu Fault Zone which in depth cut through the Moho discontinuity, its northern segment appears to have different crustal structure in its northern and southern parts. For its northern part (44.4°N-47°N), the Moho discontinuity between the two main branches appears to drop down. While for the southern part (41.5°N-43.3°N), the Moho discontinuity changes into being uplifted under the fault zone. Around the Changbaishan Tianchi volcano, the Moho discontinuity under the caldera subsides and the measurements at 3 stations (2 measurements cited from former study) with high VP/VS ratio located at the north and east of the caldera within 10 km may indicate the present crustal magma. |
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| Keywords: | NE China Receiver function Moho discontinuity VP/VS ratio Tanlu Fault Zone Changbaishan Tianchi volcano |
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