Origin and age of magmatism in the Red River shear zone, Yunnan, China

1998 ◽  
Vol 43 (S1) ◽  
pp. 113-113
Author(s):  
U. Schärer ◽  
L. S. Zhang
Keyword(s):  
Shear Zone ◽  
Red River

Structure and spatial-temporal relationship of potassic magmatism linked to a continental-scale strike-slip shear zone and post-collisional Cenozoic extension

2021 ◽  
Author(s):  
junyu Li ◽  
shunyun Cao ◽  
Xuemei Cheng ◽  
Haobo Wang ◽  
Wenxuan Li
Keyword(s):  
Partial Melting ◽  
Shear Zone ◽  
Continental Crust ◽  
Red River ◽  
Compositional Variation ◽  
Continental Scale ◽  
Magmatic Rocks ◽  
Western Yunnan ◽  
Potassic Rocks ◽  
Potassic Magmatism

<p>Adakite‐like potassic rocks are widespread in post-collisional settings and provide potential insights into deep crustal or crust-mantle interaction processes including asthenosphere upwelling, partial melting, lower crustal flow, thickening and collapse of the overthickened orogen. However, petrogenesis and compositional variation of these adakite‐like potassic rocks and their implications are still controversial. Potassic magmatic rocks are abundant developed in the Jinshajiang–Ailaoshan tectono-magmatic belt that stretches from eastern Tibet over western Yunnan to Vietnam. Integrated studies of structure, geochronology, mineral compositions and geochemistry indicate adakite-like potassic rocks with different deformation are exposed along the Ailaoshan-Red River shear zone. The potassic felsic rocks formed by mixing and partial melting between enriched mantle-derived ultrapotassic and thickened ancient crust-derived magmas. The mixing of the mafic and felsic melts and their extended fractional crystallization of plagioclase, K-feldspar, hornblende and biotite gave rise to the potassic magmatic rocks. Zircon geochronology provide chronological markers for emplacement at 35–37 Ma of these adakite-like potassic rocks along the shear zone. Temperature and pressure calculated by amphibole-plagioclase thermobarometry range from 3.5 to 5.9 kbar and 650 to 750 ℃, respectively, and average emplacement depths of ca. 18 km for granodiorite within this suite. In combination with the results of the Cenozoic potassic magmatism in the Jinshajiang–Ailaoshan tectono-magmatic belt, we suggest that in addition to partial melting of the thickened ancient continental crust, magma underplating and subsequent crust-mantle mixing beneath the ancient continental crust have also played an important role in crustal reworking and strongly affected the rheological properties and density of rocks. The exhumation underlines the role of lateral motion of the Ailaoshan-Red River shear zone initiation by potassic magma-assisted rheological weakening and exhumation at high ambient temperatures within the shear zone.</p>

Cenozoic rifting and inversion of Beibuwan Basin and its linkage with the strike-slip movement along the Ailao Shan-Red River Shear Zone

2021 ◽  
pp. 1-18
Author(s):  
Yanjun Cheng ◽  
Zhiping Wu ◽  
Jie Zhang ◽  
Yuqing Liu ◽  
Zhengkai Wang ◽  
...  
Keyword(s):  
Shear Zone ◽  
Strike Slip ◽  
Red River ◽  
And Inversion ◽  
Strike Slip Movement

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 Structure and shearing conditions in the Day Nui Con Voi massif: Implications for the evolution of the Red River shear zone in northern Vietnam

Tectonics ◽  
2007 ◽  
Vol 26 (2) ◽  
pp. n/a-n/a ◽  
Author(s):  
R. Anczkiewicz ◽  
G. Viola ◽  
O. Müntener ◽  
M. F. Thirlwall ◽  
Igor M. Villa ◽  
...  
Keyword(s):  
Shear Zone ◽  
Red River ◽  
Northern Vietnam

scholarly journals Diffusional homogenization of light REE in garnet from the Day Nui Con Voi Massif in N-Vietnam: Implications for Sm–Nd geochronology and timing of metamorphism in the Red River shear zone

2012 ◽  
Vol 318-319 ◽  
pp. 16-30 ◽  
Author(s):  
Robert Anczkiewicz ◽  
Matthew Thirlwall ◽  
Olivier Alard ◽  
Nick W. Rogers ◽  
Chris Clark
Keyword(s):  
Shear Zone ◽  
Red River ◽  
Diffusional Homogenization
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