Constraining modes and rates of horizontal deformation along east Qinling fault system from rotated river basins

Abstract

The planform rotation of river basins has been used as a marker of crustal strain and been used to assess the style and rates of on‐fault deformation. We use the geometry of river basins to evaluate horizontal deformation associated with the South China–North China relative block motion in the east Qinling mountains. The long‐time average slip rates of the Luonan fault and Shangdan fault are constrained as 0.31 mm/year and 0.3–0.6 mm/year, respectively. According to the latest GPS, we believe that a minor portion of the crustal strain of relative block motion between North China and South China was partitioned into the east Qinling strike‐slip fault system, leaving a major portion of deformation to be accommodated by southern North China (SNC). We conclude that the eastward extrusion of South China cannot explain the present deformation of the entire eastern China, and more attention should be paid into the SNC.