Shihao Hao, Lianfu Mei, Jinyun Zheng, César R. Ranero
{"title":"南海北部的剥离和转移断层系统,对裂谷边缘三维构造划分的启示","authors":"Shihao Hao, Lianfu Mei, Jinyun Zheng, César R. Ranero","doi":"10.1029/2023tc008172","DOIUrl":null,"url":null,"abstract":"The 2D rifting modes interpreted in traditional “magma-poor” and “magma-rich” margins cannot explain the crustal structure and inferred rifting processes in the northern South China Sea (SCS) rifted margin. The “intermediate-type” terminology has been therefore applied to the mid-northern SCS, where a “wide-rift” model has been widely accepted. However, the tectono-magmatic processes of the SCS are still debated and at least five contrasting models exist. We present a compilation of 3-D seismic volumes and regional 2-D seismic surveys covering the entire Baiyun and Liwan Sub-basins to investigate their tectonic structure and faulting style in this “wide-rift” region. We interpret two segments with contrasting tectonic styles separated by a volcanic lineament and steep transfer faults. The Baiyun Sub-basin was controlled by a landward-dipping detachment system. The Liwan Sub-basin, however, was formed by a ∼100 km-long oceanward-dipping, concave-up detachment fault working at a low angle of <10°. The lateral boundaries of the detachment system were mechanically decoupled from surrounding tectonics by a volcanic lineament/transfer zone to the west and <i>a</i> > 190 km-long N-S-trending left-lateral strike-slip fault to the east. The planar low-angle detachment does not resemble classical metamorphic core complex domes interpreted previously. Our results indicate a 60-80 km-wavelength segmentation within a single “wide-rift” system, indicating complex 3D rifting during crustal extension. This study supports that the intermediate SCS margin had a kinematically complex deformation style locally dominated by the interaction between detachment and transfer fault systems that might be yet unrecognized in other margins.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":"42 1","pages":""},"PeriodicalIF":3.3000,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Detachment and Transfer Fault Systems in the Northern South China Sea, Insights Into 3D Tectonic Segmentation of Rifted Margins\",\"authors\":\"Shihao Hao, Lianfu Mei, Jinyun Zheng, César R. Ranero\",\"doi\":\"10.1029/2023tc008172\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"The 2D rifting modes interpreted in traditional “magma-poor” and “magma-rich” margins cannot explain the crustal structure and inferred rifting processes in the northern South China Sea (SCS) rifted margin. The “intermediate-type” terminology has been therefore applied to the mid-northern SCS, where a “wide-rift” model has been widely accepted. However, the tectono-magmatic processes of the SCS are still debated and at least five contrasting models exist. We present a compilation of 3-D seismic volumes and regional 2-D seismic surveys covering the entire Baiyun and Liwan Sub-basins to investigate their tectonic structure and faulting style in this “wide-rift” region. We interpret two segments with contrasting tectonic styles separated by a volcanic lineament and steep transfer faults. The Baiyun Sub-basin was controlled by a landward-dipping detachment system. The Liwan Sub-basin, however, was formed by a ∼100 km-long oceanward-dipping, concave-up detachment fault working at a low angle of <10°. The lateral boundaries of the detachment system were mechanically decoupled from surrounding tectonics by a volcanic lineament/transfer zone to the west and <i>a</i> > 190 km-long N-S-trending left-lateral strike-slip fault to the east. The planar low-angle detachment does not resemble classical metamorphic core complex domes interpreted previously. Our results indicate a 60-80 km-wavelength segmentation within a single “wide-rift” system, indicating complex 3D rifting during crustal extension. This study supports that the intermediate SCS margin had a kinematically complex deformation style locally dominated by the interaction between detachment and transfer fault systems that might be yet unrecognized in other margins.\",\"PeriodicalId\":22351,\"journal\":{\"name\":\"Tectonics\",\"volume\":\"42 1\",\"pages\":\"\"},\"PeriodicalIF\":3.3000,\"publicationDate\":\"2024-08-31\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Tectonics\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://doi.org/10.1029/2023tc008172\",\"RegionNum\":1,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"GEOCHEMISTRY & GEOPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Tectonics","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1029/2023tc008172","RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
Detachment and Transfer Fault Systems in the Northern South China Sea, Insights Into 3D Tectonic Segmentation of Rifted Margins
The 2D rifting modes interpreted in traditional “magma-poor” and “magma-rich” margins cannot explain the crustal structure and inferred rifting processes in the northern South China Sea (SCS) rifted margin. The “intermediate-type” terminology has been therefore applied to the mid-northern SCS, where a “wide-rift” model has been widely accepted. However, the tectono-magmatic processes of the SCS are still debated and at least five contrasting models exist. We present a compilation of 3-D seismic volumes and regional 2-D seismic surveys covering the entire Baiyun and Liwan Sub-basins to investigate their tectonic structure and faulting style in this “wide-rift” region. We interpret two segments with contrasting tectonic styles separated by a volcanic lineament and steep transfer faults. The Baiyun Sub-basin was controlled by a landward-dipping detachment system. The Liwan Sub-basin, however, was formed by a ∼100 km-long oceanward-dipping, concave-up detachment fault working at a low angle of <10°. The lateral boundaries of the detachment system were mechanically decoupled from surrounding tectonics by a volcanic lineament/transfer zone to the west and a > 190 km-long N-S-trending left-lateral strike-slip fault to the east. The planar low-angle detachment does not resemble classical metamorphic core complex domes interpreted previously. Our results indicate a 60-80 km-wavelength segmentation within a single “wide-rift” system, indicating complex 3D rifting during crustal extension. This study supports that the intermediate SCS margin had a kinematically complex deformation style locally dominated by the interaction between detachment and transfer fault systems that might be yet unrecognized in other margins.
期刊介绍:
Tectonics (TECT) presents original scientific contributions that describe and explain the evolution, structure, and deformation of Earth¹s lithosphere. Contributions are welcome from any relevant area of research, including field, laboratory, petrological, geochemical, geochronological, geophysical, remote-sensing, and modeling studies. Multidisciplinary studies are particularly encouraged. Tectonics welcomes studies across the range of geologic time.