Abstract:

The responding to neotectonic movement in Wujiawan River, which runs through transition area of two geomorphic units of Taihang Mountains and the North China Plain, is more sensitively than other water systems in Taihang Mountains, so it can record the history of uplift better. By the field investigation of sequence and sedimentary features, dating of optical stimulated luminescence(OSL), the conclusions can be reached that there are four levels of river terraces in Pingdian River, the lower reaches of Wujiawan River, T4, T3, T2 and T1 terraces heights are 61-96 m, 35-54 m,19-43 m and 3-5 m, and ages are 97.4 kaBP, 73.9 kaBP, 48.3 kaBP and 2.3 kaBP respectively. After investigation the causes of river terraces, T4, T3, T2 terraces should be the results of tectonic uplift, otherwise T1 is climatic terrace. It reveals that the amplitude of uplift of the area is 90 m at least after three stages of stable sedimentation and rapid uplift since Late Pleistocene(Qp3), the amplitude and the rate of uplift are 26-42 m and 1.11-1.79 mm/a, 11-27 m and 0.43-1.05 mm/a, 16-39 m and 0.35-0.85 mm/a. This study is of great value, which provides actual material for the research of river terrace and neotectonic movement on the southern margin of Taihang Mountains.

Key words: Taihang Mountains；Pingdian River；Late Pleistocene(Qp3), river terrace；OSL dating；neotectonic movement