Environmental magnetic evidence for enhanced aridification in the Tarim Basin since ～5.3 Ma, NW China

摘要

The Tarim Basin, located in the rain shadow of High Asia, is an ideal basin for studying the long-term aridification history and the interplay between climate and regional tectonics. Here we report new environmental magnetic records from the foreland basin of southern Tian Shan. Our new magnetic records, together with the results of color parameters, suggest that the paleoenvironment in the study area changed abruptly since similar to 5.3 Ma. This result is consistent with other paleoclimatic records from different parts of the Tarim Basin, suggesting a basin-wide extreme aridification prevailed in the Tarim Basin since the beginning of the Pliocene. The long-term cooling trend of the climate in the Tarim Basin since the late Miocene was generally controlled by first-order global climate. However, the extreme aridification since similar to 5.3 Ma was dominantly controlled by decreased moisture transport caused by the final collision between Pamir and Tian Shan as a response to the northward displacement of the Pamir salient.