The concealed active tectonics and their characteristics as revealed by drainage density in the North China plain (NCP)

摘要: Abstract Drainage density, defined as river length per unit area, is an important tool to reveal the concealed active tectonics in Quaternary-covered North China plain (NCP). The distribution of high-drainage density characteristic zonation and regionalisation. There are two sets belts with densities, which trend at 45–50 315–320°. different locations trends these make it possible divide NCP into three regions. They Beijing–Tianjin–Tangshan region north, Jizhong–Lubei middle Xingtai south. Similarly located regions can be using contours deformation data from geodetic-surveys 1968 1982. Belts spatially coincident seismotectonic zones overlie faults. These structures strike angle ≈15° that Eocene–Oligocene, a discordance, may indication evolution fault pattern through time during Cenozoic. current phase has more consequences regarding seismic hazards NCP.