Response of Manas River fluvial landforms to tectonic movement, at the north flank of the Tianshan Mountain, China

摘要

Manas River is the largest river at the north foot of Tianshan Mountain, and it is obvious that the landforms at the north flank of Tianshan Mountains respond to the tectonic movement. A hypothesis has been put forward that geomorphology of the north flank of the Tianshan Mountain Range is the result of active tectonic processes. Based on the filed survey and analysis, the hypothesis has been proved by the results of the research. By investigating into the evolutions of Manas River valley fold hills, alluvial fans and terraces, it is indicated that Tianshan Mountain piedmont has been constantly uplifted along with main body of Tianshan Mountain since Quaternary, and continues to be thrust from south to north, which makes the piedmont range constantly extend to the basin direction. The deformed main body also moves from south to north. Meanwhile, the alternant Pleistocene ice age and interglacial age climate also has significant impact on the current landform patterns of north piedmont of Tianshan Mountain.