Late Miocene–Pleistocene aridification of Asian inland revealed by geochemical records of lacustrine-fan delta sediments from the western Tarim Basin, NW China

Continuous Cenozoic deposits have accumulated in the Tarim Basin, northwestern China, and are crucial to investigating the aridification history of the Asian interior, which has long been thought to be linked with the growth of the Tibetan Plateau, retreat of the Para-Tethys Sea and global cooling. However, less and poor climatic records from the region hinder our understanding of the questions above. Here we report continuous lithologic (sedimentary color) and geochemical (CaCO3 and salt ions) records from precisely dated late Miocene–early Pleistocene sedimentary sequence from western Tarim Basin, NW China. They indicate that arid climate had prevailed within the basin at latest at ca. 5.7 Ma and gradually increased in degree until ca. 3.7 Ma. Between ca. 3.7 and 2.1 Ma, a hydrologic event occurred, which supplied more water from the Tien Shan. After ca. 2.1 Ma the climate in the basin turned to hyper arid. We attribute the stepwise drying of the Asian inland since ca. 5.7 Ma to the late Miocene–Pliocene episodic uplift of the Tibetan Plateau, Pamir and the Tien Shan and the connection of the Pamir with the Tien Shan in remote response to the collision of India with Asia.