Sedimentary Characteristics And Paleoenvironmental Evolution Of RENACUO Lake At Quaternary In The Area Of Gaize, Tibetan Plateau

Qinghai-Tibet Plateau known as the world’s "Third Pole", an area of 250 × 104km2, the average height of 4500m. Since the rapid uplift of the Tibetan Plateau, resulting in a significant impact on the atmospheric circulation, the formation of the East Asian monsoon has played a crucial role to global environmental change. The current study focused on the study of ancient environmental variation within a wide range, for the paleoenvironmental studies of the lakes mainly focus on Namco, Zabuye areas. Due to the lack of the research on the Late Pleistocene stages of the environment and the deposition in Northern Tibet, so the topic of this thesis is the Quaternary sedimentary characteristics and paleoenvironmental evolution of the RENACUO Lake, Gaize area, Tibet, which is to investigate the response and the development trend of climate change of the Gaize area since the uplift.Based in structural geology, by the method of the remote sensing interpretation to interpret the formation structure of the Renacuo lake, and quantitative calculation the terraces uplift; using deposition theory, that recovery and analysis the RENACUO sedimentary environment since the Late Pleistocene; by the method of the pollen component analysis, that recovery the RENACUO area paleoenvironmental from the other side; using SEBS model and remote sensing methods, quantitative calculation the modern quantitative environmental features of the RENACUO area; By the comprehensive comparison studies, the Quaternary environmental of the RENACUO area response to global climate were discussed, then analyzed and predicted the modern environment and development trends of the RENACUO area, the thesis’s main understanding and progress as follows:By OSL dating data, the basic determining the RENACUO lacustrine terraces grew out of about 33.4kaB.P.～10.6kaB.P., belonging to the late Pleistocene. Through quantitative measurement of the infrared range finder to calculate the average uplift rate of northwestern part of the RENACUO Lake is 0.17mm/a; the average uplift rate of south part of the RENACUO Lake is 0.62mm/ a. Order by sediments characteristic analysis and pollen component analysis of the lacustrine terraces, restoring the RENACUO that experienced the evolution from the mild and slightly dry before 33.4kaBP to gradually damp and warm; temperatures continue to rise during 33.4kaBP～30.9kaBP, humid environment, but the relatively turn to drought; the climate turn to arid during 30.9kaBP～27.0kaBP and the temperature decreased gradually; the temperature sharply decline during 27.0kaBP～21.3kaBP, the climate turn to humid gradually; the temperature reduce but first elevated during 21.3kaBP～ 10.6kaBP, the climate turn to arid; the climate gradually warming after 10.6kaBP and on the transformation from arid to humid over the process. On a regional scale, global climate time have a good response of the MIS3, MIS2 stages, indicating that the response to global climate change of the RENACUO lake is very sensitive, which can indicate the general rules of global climate change. By SEBS model and using remote sensing satellite data, the calculated these parameters of the RENACUO evaporation, precipitation, suggesting that climate will continues evolve to arid.