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| Liu, Siqing; Zhao, Minghui; Sibuet, Jean-claude; Qiu, Xuelin; Wu, Jonny; Zhang, Jiazheng; Chen, Chuanxu; Xu, Ya; Sun, Longtao. |
| An E-W oriented OBS2015-2 wide-angle refraction profile was shot in the northeastern South China Sea (SCS) between refraction profiles T1 and T2 in order to better understand the variability of the crustal composition and the role of specific tectonic features. P-wave velocity models established from forward and inversion modeling imaged a 12 to 15 km-thick thinned continental crust and a high velocity layer (HVL) in the lower crust which is interpreted as magmatic underplating. Profile OBS2015-2 cut across the Taiwan transfer zone (TTZ), which separates two consecutive rifted segments of different orientations in the northeastern SCS. The TTZ is a well-defined upper crustal feature characterized by a HVL with different thickness on both sides. We have... |
| Tipo: Text |
Palavras-chave: Northeastern South China Sea; Continent-ocean boundary (COB); Wide-angle reflection/refraction data; Thinned continental crust intruded by post-rifting volcanism; Taiwan transfer zone (TTZ). |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00443/55458/56974.pdf |
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| Zhao, Minghui; Sibuet, Jean-claude; Wu, Jonny. |
| Recent studies have shown the extent and nature of the South China Sea (SCS) at the end of spreading by unfolding (i.e. structurally restoring) the Manila slab, which is the subducted part of the SCS, and by identifying the nature of the crust-lithosphere (oceanic or thinned continental) from mid-slab P-wave velocity perturbations (dVp) [1,2]. The objective of this paper is to propose a reconstruction of the SCS at the end of seafloor spreading and to discuss its geodynamic consequences in the context of the SCS and Philippine Sea plate (PSP) evolution. Reasonably accurate PSP paleo-latitudes and poorly defined paleo-declinations were primarily used to establish the kinematic evolution of the PSP through time (e.g. [3,4]) until 2016, when Wu et al. [1]... |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00611/72275/71069.pdf |
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| Sibuet, Jean-claude; He, Enyuan; Zhao, Minghui; Pang, Xinming; Klingelhoefer, Frauke. |
| In the late 90's, some faults identified within oceanic crust were demonstrated to be artifacts arising from out-of-plane scattering along linear sediment-buried fault scarps. Symmetrical mantle reflections observed southwest northern Sumatra on seismic reflection profiles have been identified as faults cutting through the upper mantle down to unprecedented depths reaching similar to 45 km. Seawater being conveyed along sub-vertical re-activated fracture zones (FZs) to the upper mantle, the mantle portions of FZs are serpentinized and act as mirrors for seismic rays. We suggest that the mantle features are not faults but artifacts resulting from out-of-plane reflections on these mirrors. Two perpendicular seismic profiles crossing the same FZ display two... |
| Tipo: Text |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00516/62771/67173.pdf |
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| Zhao, Minghui; He, Enyuan; Sibuet, Jean-claude; Sun, Longtao; Qiu, Xuelin; Tan, Pingchuan; Wang, Jian. |
| P-wave velocity models were obtained by forward and inverse modeling from 38 ocean bottom seismometers deployed in the central East sub-basin of the South China Sea (SCS). Four types of crust have been defined; a) thin oceanic crust (<5 km), b) typical oceanic crust (5-6 km), c) thick oceanic crust hosting post-spreading volcanoes (>6 km) with significant intrusive roots, and d) thick oceanic crust with enhanced spreading features (>6 km) but without significant roots. Within the central East sub-basin, the thin oceanic crust, only identified inside a 80-km wide zone, is located within an overall 150-km wide domain characterized by N055° seafloor spreading trends. The post-spreading volcanoes were formed during a N-S tensional episode around 6-10... |
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| Ano: 2018 |
URL: http://archimer.ifremer.fr/doc/00427/53882/54951.pdf |
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| Huang, Haibo; Qiu, Xuelin; Pichot, Thibaud; Klingelhoefer, Frauke; Zhao, Minghui; Wang, Ping; Hao, Tianyao. |
| Evolution of the continental margins of the South China Sea (SCS) is one of the open questions when discussing continental breakup and seafloor spreading. We processed data from a wide-angle seismic profile (OBS2011–1), which passes through the northwestern margin of the SCS, and performed travel time modeling to obtain the seismic velocity structures. The modeling results show a stepwise variation of the crustal thicknesses from continental margin to oceanic basin. Stretching factor of the upper crust is nearly double the estimate of the lower crust along the Zhongsha Trough. The lower crust shows asymmetrical upwelling towards the trough center, accompanied by ∼0.3 km/s of the velocity increase due to magmatic addition. The upper and lower crusts have... |
| Tipo: Text |
Palavras-chave: Seismic tomography; Continental tectonics: extensional; Crustal structure; Rheology: crust and lithosphere. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00500/61189/64720.pdf |
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