Cenozoic rifting and inversion in Beibuwan Basin and its relationship with strike-slip motion on the Ailao Shan-Red River Shear Zone

2020 ◽  
Author(s):  
Yanjun Cheng ◽  
Zhiping Wu
Keyword(s):  
South China Sea ◽  
Shear Zone ◽  
South China ◽  
Tectonic Setting ◽  
Strike Slip ◽  
Red River ◽  
Eurasian Plate ◽  
The Pacific ◽  
Extensional Tectonic ◽  
And Inversion

<p>The Beibuwan basin is located along the western margin of the Ailao Shan Red River Shear Zone (ASRRSZ), and also in the north margin of the South China Sea (SCS). This study utilizes 2-D seismic data to investigate the evolution of this basin and discuss its broad tectonic settings. Several stages of rifting and inversion occurred in the Beibuwan basin during Cenozoic: (1) During Paleocene initial rifting (66-56 Ma), the ocean-ward gradual retreat of the Paleo-pacific subduction zone created an extensional tectonic setting in the SCS region. The overall extensional tectonic setting of the northern passive margin of the SCS generated a series of Paleogene NE-striking rift basins, including the Beibuwan basin, the Qingdongnan basin and the Pear River Mouth Basin. (2) During Eocene rifting stage (56-37.8 Ma), the Pacific plate still subducted under the Eurasian plate, and soft collision started to occur between the greater India plate and the Eurasian plate. Subsequently, the NW-SE-direction extension gradually changed to N-S-direction extension, therefore, the NE-striking faults active intensively during this stage, and a small group of EW-striking faults formed in the study area. (3) During the Oligocene rifting stage (37.8-23 Ma), the India-Eurasian collision went into hard collision stage, induced the large-scale left-lateral strike-slip of the ASRRSZ. Furthermore, the subduction of the Pacific plate strengthens the left-lateral shearing of the ASRRSZ. The left-lateral strike-slip of ASRRSZ resulted in the formation of large amount of EW-striking faults in the Beibuwan and Yinggehai basins, and the opening of the South China Sea. (4) After Paleogene, several stage of inversions occurred in the study area, including the end-Oilgocene, end-Miocene and end-Plioence inversions. The regional end-Oligocene inversion is supposed related to the change from major left-lateral transtensional rifting to left-lateral transpression of ASRRSZ. The end-Miocene and end-Pliocene inversions are localized inversions, which also related to the left-lateral transpression of ASRRSZ.</p>

Submarine landslides in the west continental slope of the South China Sea and their tsunamigenic potential

2021 ◽  
Author(s):  
Xiaoyi Pan ◽  
Linlin Li ◽  
Hong Phuong Nguyen ◽  
Dawei Wang
Keyword(s):  
South China Sea ◽  
Shear Zone ◽  
Continental Slope ◽  
South China ◽  
Water Depth ◽  
Red River ◽  
Submarine Landslides ◽  
The West ◽  
Tsunami Waves ◽  
Central Vietnam

<p>The 109 meridian fault is located in the west of the South China Sea (SCS) connecting to the offshore Red River Shear Zone. The evolution processes of the 109 meridian fault: striking-uplifting-subsidence of adjacent basin led to a nearly 1000m sharp bathymetric difference in the offshore region of central Vietnam. Combined with the high sediment input from numerous montane rivers in the rising hinterland, the continental slope near central Vietnam possesses the ideal condition for developing submarine landslides. Seismic data indicates many submarine landslides were developed along the steep continental slope. In this study, we analyze the possible trigger mechanisms of these landslides based on the local geological background and sedimentary environment, and assess their tsunamigenic potential along the coast of the Southern Central Vietnam (SCV). We point out that the landslide failures in this region could be triggered by several mechanisms, including seismic activities in the offshore SCV, volcanic activities, gas seep on the slope and the relative sea-level changes. The seismic and volcanic activities are related directly to the late middle Miocene volcanism generated by the change from left- to right-lateral motion on the Red River Shear Zone, showing that tectonism play a significant role in the generation of submarine landslide in the western continental slope of the SCS. To estimate the impact of tsunami waves on SCV coastline, we use two numerical models—NHWAVE and FUNWAVE-TVD to model 4 representative landslides with volume ranging between 1-4km<sup>3</sup> and water depth of 300-1000m. The submarine landslides were treated as rigid slump and deformable slide corresponding to two different sedimentary environments. Our results show that the tsunami waves generated by rigid slump can reach up to 20m height in the landslide source area and arrive earlier to the coast of SCV than waves generated by deformable slide. Among these simulated scenarios, tsunami waves generated by the worst-case scenario arrive at the populated cities including Quy Nhơn (109.3°E,13.77°N), Tuy Hòa (109.37°E ,13.08°N) and Vung Ro Bay (109.43°E，12.86°N) in less than 25mins with maximum height of 5m. It is worth mentioning that the Vung Ro Bay will be affected by tsunami waves in all simulated scenarios. We quantify the influence of landslide characteristics (volume, water depth and material) and highlight the local effect of coastal bathymetry on the tsunami generation and propagation which lead to different hazard level of SCV coast.</p>

scholarly journals Geometry, kinematics and regional significance of faulting and related lamprophyric intrusion in the mineralised zone at the Pu Sam Cap complex, Northwest Vietnam

2018 ◽  
Vol 40 (4) ◽  
pp. 320-340 ◽  
Author(s):  
Findlay R. H.
Keyword(s):  
Shear Zone ◽  
South China ◽  
Shear Zones ◽  
Planetary Science ◽  
Strike Slip ◽  
Red River ◽  
Fault System ◽  
Lateral Shear ◽  
Geological Society ◽  
Se Asia

The alkali volcanics and intrusive rocks, dated at around 35-33Ma, are cut by mineralised northeast and east trending faults showing predominant evidence for strike-slip. Mineralisation includes haematite-Au-Cu and is accompanied by iron-rich alteration of the volcanic rocks. Detailed assessment of the geometry of the fault system at Pu Sam Cap suggests that the faults formed as a Riedel shear system during left-lateral slip within the Song Hong-Song Chay shear zone and the numerous contemporaneous northwest trending faults to the south; the northeast trending faults are interpreted as dextral “book-end’’ faults between major northwest trending faults enclosing the Pu Sam Cap massif. As mineralisation is hosted within these faults and is also associated with lamprohyric dykes it confirms a thermal event younger than the alkaline volcanics and syenitic intrusives at Pu Sam Cap, suggesting a hidden, young porphyry system. The age of faulting, and thus the maximum age for this young intrusive event, is attributed to the 23-21Ma period of late-stage left-lateral strike-slip motion across northwest Vietnam.ReferencesAnczkiewicz R., Viola G., Muntener O., Thrirlwall M., Quong N.Q., 2007. Structure and shearing conditions in the Day Nui Con Voi massif: implications for the evolution of the Red River Fault. Tectonics 26: TC2002.Cao Shunyun, Liu Junlai, Leis B., Zhao Chunquiang 2010. New zircon U/Pb geochronology of the post-kinematic granitic plutons in Diancang Shan Massif along the Ailao-Shan-Red River Shear Zone and its geological implications. Acta Geologica Sinica (English Edition), 84, 1474-1487.Chung S.-L., Lee T., Lo C.,  et al., 1997. Intraplate extension prior to continental extrusion along the Ailao Shan-Red River shear zone.Geology, 25, 311-314.Cloos H., 1928. Experimentezurinnern Tektonik.  Zentralblatt fur Mineralogie und Palaeontologie, 1928, 609-621.Findlay R.H., Phan Trong Trinh 1997. The structural setting of the Song Ma region, Vietnam, and the Indochina-South China plate boundary problem. Gondwana Research, 1, 11-33.Jolivet L., Beysasac O., Goffe B., Avigad D., Leprevrier C., Maluski H., Ta Trong Thang, 2001. Oligo-Miocene midcrustal subhorizontal shear in Indochina. Tectonics, 20, 46-57.Khuong The Hung 2010. The complex tectonic events and their influence on formation of mineral deposits in northwest Vietnam. Unpublished PhD Thesis, University of Science and Technology, Cracow, 167p.Leloup P.H., N. Arnau,  R. Lacassin, J.R. Kienast, T.M. Harrison, P.T. Trinh, A. Replumaz and P. Tapponnier, 2001. New constraints on the structure, thermochronology and timing of the Ailao Shan - Red river shear zone, SE Asia, J. G. R., 106, 6657-6671.Leloup  PH.., R. Lacassin, P. Tapponnier, U. Scharer, Zhong Dalai, Liu Xaohan, Zhangshan, Ji Shaocheng and PT.Trinh, 1995. The Ailao Shan - Red river shear zone (Yunnan, China), Tertiary transform boundary of Indochina, Tectonophysics, 251, 3-84. Leprevier C., Maluski H., Nguyen Van Vuong, Roques D., Axente V., Rangin C., 1996. Indosinian NW-trending shear zones within the Truong Son belt, Vietnam: 40Ar-39Ar Triassic ages and Cretaceous to Cenozoic overprints. Tectonophysics, 283, 105-107.Lien-Sheng Zhang, Scharer U. 1999. Age and origin of magmatism along the Cenozoic Red River shear belt, China. Contributions to Mineralogy and Petrology, 134, 67-85.Nagy E.A., Scharer U., Minh N.T., 2000. Oligo-Miocene granitic magmatismin central Vietnam and implications for continental deformation in Indochina. Terra Nova, 12, 67-76.Nguyen Thi Bich Thuy, 2016. Isotop dating U-Pb Zircon of Syenit Formation, Pu Sam Cap. Journal of Geology, A Serie, 356, 30-36. (In Vietnamese).Pei-Long Wang, Ching-Hua Lo, Tung-Yi Lee, Sun-ling Chun, Ching-Yan Lan, Nguyen Trong Yem 1998. Thermochronological evidence for the movement of the Ailo Shan-Red River shear zone, a perspective from Vietnam. Geology, 26, 887-890.Phan Trong Trinh, Nguyen Trong Yem, Herve L.P., Tapponnier P., 1994. Late Cenozoic stress fields in North Vietnam from microtectonic measurements. Proceedings of the International Workshop on Seismotectonics and Seismic Hazard in Southeast Asia. Geological Survey of SR Vietnam, Hanoi, 182-186.Riedel W., 1929. Zur Mechanikgreologischer Brucherscheinungen. Zentralblatt fur Mineralogie und Palaeontologie, Abhandlung B, 354-368.Scharer U., Tapponnier P., Lacassin R., Leloup P.H., Dalai Z., Shaosheng J., 1990. Intraplate tectonics in Asia: a precise age for large-scale Miocene movement along the Ailao Shan-Red River shear zone, China. Earth  and Planetary Science Letters, 97, 65-77.Scharer U., Zhang L.S., Tapponnier P., 1994. Duration of strike-slip movements in large shear zones: the Red River belt, China. Earth and Planetary Science Letters, 126, 379-397.Searle M.P., 2006. Role of the Red River Shear zone, Yunnan and Vietnam, in the continental extrusion of SE Asia. Journal of the Geological Society, London, 163, 1025-1036.Searle M.P., Meng-Wan Yeh, Te-Hsien Lin, Sun-Lin Chung, 2010. Structural constraints on the timing of left-lateral shear along the Red River shear zone in the Ailao Shan and Diancang Shan Ranges, Yunnan, SW China. Geosphere, 6, 316-338.Tapponnier P., Lacassin R., Leloup H., Scharer U., Zhong Dalai, Wu Hawei, Liu Ziaohan, Ji Shaocheng, Zhang Lianshang, Zong Jiayou, 1990. The Ailao Shan/ Red River metamorphic belt: Tertiary left-lateral shear between Indochina and south China. Nature, 342, 431-437.Tchalenko J.S., 1970.  Similarities between shear zones of different magnitudes. Bulletin of the Geological Society of America, 81, 1625-1640.Viola G., Anczkiewicz R. 2009. Exhumation history of the Red River shear zone in northern Vietnam:  new insights from zircon and apatite fission-track analysis. Journal of Asian Earth Sciences, 33, 78-90.Yang Yiseng, Hong Qun, Hu Huan-ting, Hieu Pham Trung, Nguyen Thi Bich Thuy, Chen Fu-kun, 2013. Geochemical characteristics and genesis of the Cenozoic porphyry in the Laizhou area, northwestern Vietnam. Acta Petrologica Sinica, 29(3), 899-911. (In Chinese with English abstract, full English version through Google Translate).

The Red River Fault zone in the Yinggehai Basin, South China Sea

2009 ◽  
Vol 476 (3-4) ◽  
pp. 397-417 ◽  
Author(s):  
Mangzheng Zhu ◽  
Stephan Graham ◽  
Tim McHargue
Keyword(s):  
South China Sea ◽  
Fault Zone ◽  
South China ◽  
Red River ◽  
China Sea ◽  
Yinggehai Basin ◽  
Red River Fault

Observation and inversion of very-low-frequency seismo-acoustic fields in the South China Sea

2020 ◽  
Vol 148 (6) ◽  
pp. 3992-4001
Author(s):  
Shuyuan Du ◽  
Jingpu Cao ◽  
Shihong Zhou ◽  
Yubo Qi ◽  
Lei Jiang ◽  
...  
Keyword(s):  
South China Sea ◽  
South China ◽  
Low Frequency ◽  
The South China Sea ◽  
Acoustic Fields ◽  
The South ◽  
Very Low Frequency ◽  
China Sea ◽  
And Inversion

Features of the Distribution of Abnormal Gasgeochemical Fields in the Red River Rift (Gulf of Tonkin, South China Sea)

2019 ◽  
Vol 484 (2) ◽  
pp. 181-184 ◽  
Author(s):  
R. B. Shakirov ◽  
Duong Quoc Hung ◽  
N. S. Syrbu ◽  
Le Duc Anh ◽  
A. I. Obzhirov ◽  
...  
Keyword(s):  
South China Sea ◽  
South China ◽  
Red River ◽  
China Sea ◽  
Gulf Of Tonkin

scholarly journals The Changing Influences of ENSO and the Pacific Meridional Mode on Mesoscale Eddies in the South China Sea

2019 ◽  
Vol 32 (3) ◽  
pp. 685-700 ◽  
Author(s):  
Pengfei Tuo ◽  
Jin-Yi Yu ◽  
Jianyu Hu
Keyword(s):  
South China Sea ◽  
Wind Stress ◽  
South China ◽  
Southern Oscillation ◽  
The South China Sea ◽  
Eddy Correlation ◽  
The South ◽  
Vector Method ◽  
China Sea ◽  
The Pacific

This study finds that the correlation between El Niño–Southern Oscillation (ENSO) and the activity of mesoscale oceanic eddies in the South China Sea (SCS) changed around 2004. The mesoscale eddy number determined from satellite altimetry observations using a geometry of the velocity vector method was significantly and negatively correlated with the Niño-3.4 index before 2004, but the correlation weakened and became insignificant afterward. Further analyses reveal that the ENSO–eddy relation is controlled by two major wind stress forcing mechanisms: one directly related to ENSO and the other indirectly related to ENSO through its subtropical precursor—the Pacific meridional modes (PMMs). Both mechanisms induce wind stress curl variations over the SCS that link ENSO to SCS eddy activities. While the direct ENSO mechanism always induces a negative ENSO–eddy correlation through the Walker circulation, the indirect mechanism is dominated by the northern PMM (nPMM), resulting in a negative ENSO–eddy correlation before 2004, and by the southern PMM (sPMM) after 2004, resulting in a positive ENSO–eddy correlation. As a result, the direct and indirect mechanisms enhance each other to produce a significant ENSO–eddy relation before 2004, but they cancel each other out, resulting in a weak ENSO–eddy relation afterward. The relative strengths of the northern and southern PMMs are the key to determining the ENSO–eddy relation and may be related to a phase change of the interdecadal Pacific oscillation.

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