EGU22-6782, updated on 28 Mar 2022
https://doi.org/10.5194/egusphere-egu22-6782
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Strike-slip motion in the Late Mesozoic on the East Asian continental margin: Insight from 3-D numerical models with the Tan-Lu fault

Meng Zhou, Ting Yang, Lijun Deng, and Peng Guo
Meng Zhou et al.
  • Department of Earth and Space Sciences, Southern University of Science and Technology, Shenzhen, China

It is widely accepted that the subduction system along an active continental margin has significant impacts on continental motions and deformation. The longest strike-slip fault in East Asian, the Tan-Lu Fault extends through the lithosphere and parallels the East Asian margin trench could be recognized as weak zone and left more significant geological information of plate tectonics than surrounding areas ( Collettini et al., 2019 ). Previous studies have gained some common sense about the motion of the East Eurasia continent margin from the Tan-Lu fault in the Late Mesozoic. The Tan-Lu fault experienced two phases sinistral strike-slip motion under compression with a striking-length about 150~200 km ( Zhu et al.,2005, 2009; Zhao et al.,2016 ), one stage is the Late Jurassic of the obtained age of 162~150 Ma and the other stage is the Early Cretaceous of the gained age of 143Ma~132Ma ( Zhu et al.,2005, 2010, 2018; Zhang and Dong, 2008 ). However, the formation mechanism of the large strike motion is still in doubt. Zhu et al., (2018) suggest that the Mesozoic tectonism of the Tan-Lu fault zone is dominated by paleo-Pacific plate subduction and thus can reflect its subduction history, while some others think the geodynamics of the Tan-Lu fault is controlled by the combined influences of the collision between the Tibetan blocks and Eurasia and the paleo-Pacific plate subduction ( Zhang et al., 2010 ).

 

To understand whether the paleo-Pacific subduction could have a dominant impact on the tectonic activities along the Tan-Lu fault and how does it influence the overriding plate, we perform 3-D numerical simulations of oceanic-continental subduction with a weakened fault zone simulating the Tan-Lu Fault. The results indicate that the motion and deformation of the East Asian continental plate can be strongly influenced by the interaction between the paleo-Pacific plate and East Asia, especially by the coupling degree between the subduction plate and the overriding plate. The coupling degree could significantly improve when there is micro-continent from subduction plate collide with overriding plate and the overriding plate would undergo compression. The collision between micro-continents with East Eurasia continent in Late Jurassic and Early Cretaceous has been observed ( Li et al.,2020; Charvet,2013 ). From the plate reconstructions ( Müller et al.,2016 ), in the Late Mesozoic had a northward component with an average velocity 40~50 mm/yr. In our numerical model, the generation of large sinistral strike-length could explained by strong coupling caused by collision of micro-continents with Eurasia plate.

How to cite: Zhou, M., Yang, T., Deng, L., and Guo, P.: Strike-slip motion in the Late Mesozoic on the East Asian continental margin: Insight from 3-D numerical models with the Tan-Lu fault, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-6782, https://doi.org/10.5194/egusphere-egu22-6782, 2022.

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