天山乌－库公路剖面中、新生代埋藏、隆升及剥露史研究
摘要
In order to better understand the mountain-building process of the Tianshan Belt, the authors collected 7 samples of sedimentary rock, metamorphic rock and granite along Urumqi-Korla highway across the Tianshan orogenic belt, for the purpose of studying the uplift of the Tianshan Mountain and its thermal evolution history. By studying the apatite fission track of the samples, we acquired seven groups of fission track central ages which range from 78.0±4.5Ma to 31.8±2.5Ma. We also took thermal-simulation on the data of apatite fission track and obtained some new comprehensive insights. Our fission track dating and thermal-simulation results indicate that Mesozoic and Cenozoic orogeny of the Tianshan orogenic belt was not an integral unified uplifting process. Instead it appears that uplifting first commenced in the north and then gradually immigrated to the south before the Miocene. After the late Miocene, the Tianshan orogeny uplifted integrally. Calculations of the apatite-zircon mineral pair and results of thermal-simulation give the apparent uplift rate of each uplifting phase. The apparent uplift rate has generally increased since the late Cretaceous.