Evolution of Neogene Foreland Basin in Yecheng, Xinjiang, and Uplift of Northern Tibetan Plateau——II Facies Analysis

The Yecheng foreland basin is a part of the southwest sag of the Tarim Basin and contains late Cenozoic molassic deposits with great thickness. The phased evolution of the basin mirrors the uplift of the Kunlun mountains. The sedimentary environment during the Miocene was characterized by low-gradient meandering rivers, and became distal fan during the Early Pliocene. Significant change in the sedimentary environment occurred in the Late Pliocene, when the deposits were dominated by debris flow material. The basin became a proximal alluvial fan under arid climatic regime. Changes in the sedimentary environment indicate the uplift of the northern Tibetan Plateau since the Late Pliocene.