Structural boundary and deep contact relationship between the Yangtze and Cathaysia Blocks from crustal thickness gradients
The deep boundary and contact relationship between the Yangtze and Cathaysia Blocks (the major tectonic units of the Southern China Block), as well as the tectonic attributes of the Jiangnan Orogenic Belt, have remained unknown or controversial. Using data recorded by 128 portable broadband stations...
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| Format: | Article |
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Frontiers Media S.A.
2023-01-01
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| Series: | Frontiers in Earth Science |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/feart.2022.1065782/full |
| _version_ | 1797950664704262144 |
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| author | Rubing Han Dinghui Yang Qiusheng Li Wei Fu Gaohua Zhu Hongshuang Zhang Hao Chen Yongzhi Cheng |
| author_facet | Rubing Han Dinghui Yang Qiusheng Li Wei Fu Gaohua Zhu Hongshuang Zhang Hao Chen Yongzhi Cheng |
| author_sort | Rubing Han |
| collection | DOAJ |
| description | The deep boundary and contact relationship between the Yangtze and Cathaysia Blocks (the major tectonic units of the Southern China Block), as well as the tectonic attributes of the Jiangnan Orogenic Belt, have remained unknown or controversial. Using data recorded by 128 portable broadband stations and 96 permanent stations, we obtained high-resolution images of crustal thickness and Poisson’s ratio in the study area. The influences of crustal anisotropy and inclined interface were eliminated by using the newly proposed receiver function H–κ–c stacking method. We then used a gradient analysis method to obtain crustal thickness gradients at the boundary of the Yangtze and Cathaysia Blocks for the first time. Our results reveal that the crustal thickness varies from >38 km in the Qinling–Dabie Orogenic Belt to <30 km east of the Tanlu Fault and Cathaysia Block. Areas with high Poisson’s ratios (>0.27) are concentrated on the flanks of the deep fault zone and the continental margin of the study area; those with low Poisson’s ratios (<0.23) are concentrated in the Jiangnan Orogenic Belt. Large crustal thickness gradients are found beneath the eastern part of the Jiujiang–Shitai buried fault (>5 km/°). Combined with the velocity structure and discontinuity characteristics at different depths, these findings suggest that the Jiujiang–Shitai fault may constitute a deep tectonic boundary dividing the Yangtze and Cathaysia Blocks on the lithospheric scale. Moreover, our results support that the Cathaysia Block subducted northwest-ward toward the southeastern margin of the Yangtze Block in the Neoproterozoic, and that the Jiujiang–Shitai buried fault and Jiangshan–Shaoxing fault are the deep and shallow crustal contact boundaries of the two Blocks, respectively; that is, the Yangtze Block overlaps the Cathaysia Block. |
| first_indexed | 2024-04-10T22:18:41Z |
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| institution | Directory Open Access Journal |
| issn | 2296-6463 |
| language | English |
| last_indexed | 2024-04-10T22:18:41Z |
| publishDate | 2023-01-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Earth Science |
| spelling | doaj.art-788aefab71c44a4e9f70d8d7e76534d82023-01-18T04:39:03ZengFrontiers Media S.A.Frontiers in Earth Science2296-64632023-01-011010.3389/feart.2022.10657821065782Structural boundary and deep contact relationship between the Yangtze and Cathaysia Blocks from crustal thickness gradientsRubing Han0Dinghui Yang1Qiusheng Li2Wei Fu3Gaohua Zhu4Hongshuang Zhang5Hao Chen6Yongzhi Cheng7Department of Mathematical Sciences, Tsinghua University, Beijing, ChinaDepartment of Mathematical Sciences, Tsinghua University, Beijing, ChinaKey Laboratory of Deep-Earth Dynamics of Ministry of Natural Resources, Institute of Geology, Chinese Academy of Geological Sciences, Beijing, ChinaCollege of Transportation Engineering, Nanjing Tech University, Nanjing, ChinaCAS Key Laboratory of Marine Geology and Environment, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, ChinaKey Laboratory of Deep-Earth Dynamics of Ministry of Natural Resources, Institute of Geology, Chinese Academy of Geological Sciences, Beijing, ChinaSchool of Geophysics and Measurement-Control Technology, East China University of Technology, Nanchang, ChinaKey Laboratory of Deep-Earth Dynamics of Ministry of Natural Resources, Institute of Geology, Chinese Academy of Geological Sciences, Beijing, ChinaThe deep boundary and contact relationship between the Yangtze and Cathaysia Blocks (the major tectonic units of the Southern China Block), as well as the tectonic attributes of the Jiangnan Orogenic Belt, have remained unknown or controversial. Using data recorded by 128 portable broadband stations and 96 permanent stations, we obtained high-resolution images of crustal thickness and Poisson’s ratio in the study area. The influences of crustal anisotropy and inclined interface were eliminated by using the newly proposed receiver function H–κ–c stacking method. We then used a gradient analysis method to obtain crustal thickness gradients at the boundary of the Yangtze and Cathaysia Blocks for the first time. Our results reveal that the crustal thickness varies from >38 km in the Qinling–Dabie Orogenic Belt to <30 km east of the Tanlu Fault and Cathaysia Block. Areas with high Poisson’s ratios (>0.27) are concentrated on the flanks of the deep fault zone and the continental margin of the study area; those with low Poisson’s ratios (<0.23) are concentrated in the Jiangnan Orogenic Belt. Large crustal thickness gradients are found beneath the eastern part of the Jiujiang–Shitai buried fault (>5 km/°). Combined with the velocity structure and discontinuity characteristics at different depths, these findings suggest that the Jiujiang–Shitai fault may constitute a deep tectonic boundary dividing the Yangtze and Cathaysia Blocks on the lithospheric scale. Moreover, our results support that the Cathaysia Block subducted northwest-ward toward the southeastern margin of the Yangtze Block in the Neoproterozoic, and that the Jiujiang–Shitai buried fault and Jiangshan–Shaoxing fault are the deep and shallow crustal contact boundaries of the two Blocks, respectively; that is, the Yangtze Block overlaps the Cathaysia Block.https://www.frontiersin.org/articles/10.3389/feart.2022.1065782/fullYangtze blockCathaysia blockH-κ-cgradient analysisJiujiang-Shitai buried fault |
| spellingShingle | Rubing Han Dinghui Yang Qiusheng Li Wei Fu Gaohua Zhu Hongshuang Zhang Hao Chen Yongzhi Cheng Structural boundary and deep contact relationship between the Yangtze and Cathaysia Blocks from crustal thickness gradients Frontiers in Earth Science Yangtze block Cathaysia block H-κ-c gradient analysis Jiujiang-Shitai buried fault |
| title | Structural boundary and deep contact relationship between the Yangtze and Cathaysia Blocks from crustal thickness gradients |
| title_full | Structural boundary and deep contact relationship between the Yangtze and Cathaysia Blocks from crustal thickness gradients |
| title_fullStr | Structural boundary and deep contact relationship between the Yangtze and Cathaysia Blocks from crustal thickness gradients |
| title_full_unstemmed | Structural boundary and deep contact relationship between the Yangtze and Cathaysia Blocks from crustal thickness gradients |
| title_short | Structural boundary and deep contact relationship between the Yangtze and Cathaysia Blocks from crustal thickness gradients |
| title_sort | structural boundary and deep contact relationship between the yangtze and cathaysia blocks from crustal thickness gradients |
| topic | Yangtze block Cathaysia block H-κ-c gradient analysis Jiujiang-Shitai buried fault |
| url | https://www.frontiersin.org/articles/10.3389/feart.2022.1065782/full |
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