吐哈盆地是我国西部极端干旱地区，同时位于青藏高原北缘和西风带，所以研究吐哈盆地新生代的干旱化历史，对于探讨青藏高原隆升、全球气候变化等对我国西北地区气候的影响具有重要意义。吐哈盆地中硫化物矿床氧化带中表生含钾矿物（黄钾铁矾、明矾石等）的出现记录了气候由干旱-半干旱气候及向极端干旱气候的转变。本申请拟以两个矿床氧化带中的表生含钾矿物为研究对象，通过40Ar/39Ar定年法进行详细的年代学研究，确定大陆化学风化历史和风化矿物富集的时间，获得吐哈盆地更为全面的干旱化历史及干旱化在时空上的演化趋势，为探讨青藏高原隆升、全球气候变化等如何影响我国西北地区干旱化提供重要的年代学制约。丰富我国矿床学、同位素年代学和干旱区古气候的研究。

Tu-Ha basin is extreme arid region of northwestern China, and is located in the northern margin of the Tibetan Plateau and the westerlies, so the study of Cenozoic aridification of Tu-Ha basin has great significance for discussing the effects of the uplifted Tibetan Plateau and the global cooling on the paleoclimate of northwestern China. The supergene K-bearing sulfate minerals(jarosite, alunite etc) in the oxidation zone of sulfide deposits, which precipitated in arid-semiarid conditions and preserved in hyperarid conditions. In this proposal, we plan to use 40Ar/39Ar dating of supergene K-bearing sulfate minerals in two oxidation zones to determine the timing of the continental weathering and supergene enrichments, get a more comprehensive aridification history of Tu-Ha basin and the evolution trend in the space. The results of this study will play an important role on constraining the factors: the uplifted Tibetan Plateau, the global cooling, which causing the aridification of northwestern China. This proposal will enrich the study of economic geology, geochronology and the paleoclimate in arid area.