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Abstract: Propagation of faults and folds in the foreland basins of Tian Shan is an important process accommodating Cenozoic crustal shortening and mountain building, but little is known about the accurate time of the Cenozoic tectonic deformation. Based on growth strata and age determination, we show that syntectonic growth strata began to develop in the middle part of Tian Shan since 6 Ma ago. Geometry analysis indicates that formation of the growth strata is associated with progressive fold-limb rotation. Formation of the growth strata is contemporaneous with the tectonic deformation in the thrusting and folding zones. Together with the remarkable increase of sedimentation rate as well as the accumulation of coarse molasse deposits, we conclude that the late Cenozoic crustal shortening and mountain building in the region initiated since about 6 Ma and lasted to the early Pleistocene, as a consequence of intracontinental deformation within the India–Eurasia convergent system. [Copyright &y& Elsevier]

Abstract: Thick Cenozoic deposits were shed into the foreland basin of the Tian Shan Range, providing great potential for understanding the relationship between tectonic history and paleoclimatic changes. In the present study, we compiled a pollen record for the interval 26.5–2.6 Ma based on a palynological analysis of a latest Oligocene–Pliocene stratigraphic sequence in the northern foreland basin of the Tian Shan. Our results indicate that a remarkable warm climate occurred at ca. 18–15 Ma ago, corresponding to the Mid-Miocene Climatic Optimum, while a change to an arid climate occurred at 6 Ma, marked by an increase in the drought-tolerant herb taxa Artemisia and Chenopodiaceae. This latter change was coincident with the late Cenozoic climatic deterioration recorded at high latitudes in the Northern Hemisphere. These inferred climatic events are further supported by the results of principal component analysis of the pollen data, such records are important archives in reconstructing the paleoclimate of the Asian interior. [Copyright &y& Elsevier]