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Geoscience ›› 2023, Vol. 37 ›› Issue (05): 1100-1109.DOI: 10.19657/j.geoscience.1000-8527.2023.020

• Structural Geology • Previous Articles     Next Articles

Fluvial Geomorphology of the Eastern Altyn Tagh and Its Tectonic Activity Implications

LU Fang(), GAO Mingxing(), ZHOU Shuxian, WANG Shun   

  1. School of Geology and Mining Engineering, Xinjiang University, Urumqi, Xinjiang 830017, China
  • Received:2022-08-31 Revised:2023-03-07 Online:2023-10-10 Published:2023-11-14

Abstract:

The Altyn Tagh strike-slip fault zone is the major control fault at the northern margin of the Qinghai-Tibet Plateau, and plays a vital role in the Cenozoic crustal deformation of the plateau.We extracted and calculated five geomorphic indices (slope, relief amplitude, fractal dimension, hypsometric integral, and stream length gradient) of 173 sub-basins by ArcGIS software.The geomorphic indices of each sub-basin were classified into five types.Their arithmetic mean values were used as relative tectonic activity indices, in order to quantitatively analyze the topographical features and the tectonic activity intensity.We show that Altyn Tagh strike-slip fault zone is the dividing line for the relative tectonic activity intensity of the whole study area, and the relative tectonic activity index level gradually decreases from south to north, and from high to low mountai-nous areas.From the spatial distribution of the relative activity tectonic index grade, the tectonic activity in the Danghe and Yemahe River basins appears to be stronger, and the intensity gradually decreases from west to east.In addition, we combine the influence of rocks, precipitation, and tectonics on the geomorphic index.Our results show that tectonics is the main factor controlling the geomorphic development in the watershed of the Altyn Tagh strike-slip fault zone, the relative tectonic activity intensity in the watershed where the seismic point is located, the watershed on both sides of the fracture zone, and the stress transition zone are higher than those in other surrounding watersheds.

Key words: geomorphic index, Altyn Tagh fault, relative tectonic activity index, strike-slip fault

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