Geomorphic analysis of active fold growth and landscape evolution in the central Qiulitage fold belt, southern Tian Shan, China

Abstract

The Qiulitage fold-and-thrust system in the Kuqa foreland is a prominent NE-SW trending relief associated with active thrust-related folding in the southern Tian Shan. Based on open-access DEMs and field work, we carried out a detailed geomorphologic analysis of the Qiulitage topography based on drainage network characteristics and several morphometric indices. Our results suggest that the Qiulitage fold belt is composed of six morphological units, which are statistically confirmed by a principal component analysis. These morphologic structures have interacted during both vertical growth and lateral propagation of the folds, associated with different patterns of fold connection and deformation partitioning. The structural evolution of the Qiulitage fold belt has significantly influenced major rivers crossing the fold belt and minor ones developing on the fold ridges. We finally propose a morphotectonic evolution of the fold belt integrating the influence of décollement distribution, deep inherited structures, and changes in shortening amount.