The fluvial terrace sequence in eastern Qilian Mountains is a record of periodic uplift events of the Tibetan Plateau. Based on paleomagnetic dating, thermolumines-cence dating, radio carbon dating and loess-paleosol ...The fluvial terrace sequence in eastern Qilian Mountains is a record of periodic uplift events of the Tibetan Plateau. Based on paleomagnetic dating, thermolumines-cence dating, radio carbon dating and loess-paleosol sequence on terraces, we preliminarily determine the ages of five major terraces of the Shagou River, northern side of the Qilian Mountains. The ages of five terraces were about 830, 418, 250,140 and 10 ka, respectively. Analysis on characteristics of terraces show that five major terraces were mainly tectonic genesis. Therefore, five major terraces recorded five strong rising events in the Qilian Mountains during the past 830 ka. The ages of those rising events are about the same as those terraces formation. Sub-terraces, constituting a main terrace, were perhaps mainly formed by climatic changes.展开更多
The selection of high-resolution loess sections is needed in order to determine the climatic variability of the East Asian Monsoon during the last interglacial. Two sequences of S1 on the eastern and west-ern sides of...The selection of high-resolution loess sections is needed in order to determine the climatic variability of the East Asian Monsoon during the last interglacial. Two sequences of S1 on the eastern and west-ern sides of the Liupan Mountain were both composed of five paleosol layers and four loess layers,indicating that there were five strong summer monsoon events and four strong winter monsoon events in MIS5. This corresponds with other records of the East Asian Monsoon,along with NGRIP and the North Atlantic records,implying that the climate of the Northern Hemisphere was very instable during the last interglacial. Two layers of paleosols and one layer of loess had developed during MIS5a and MIS5c. Compared with MIS5e,the climate in MIS5a and MIS5c fluctuated more intensively on a millen-nial scale,whereas the climate was relatively stable in MIS5e.展开更多
基金theNational Natural Science Foundation of China (Grant No. 49731010), the National Key Basic Research Project (Grant No. G1998040800), the Qinghai-Tibetan Plateau Research Project of the CAS (Grant Nos. KZ951-A1-204 and KZ95t-06) and the Key Project of
文摘The fluvial terrace sequence in eastern Qilian Mountains is a record of periodic uplift events of the Tibetan Plateau. Based on paleomagnetic dating, thermolumines-cence dating, radio carbon dating and loess-paleosol sequence on terraces, we preliminarily determine the ages of five major terraces of the Shagou River, northern side of the Qilian Mountains. The ages of five terraces were about 830, 418, 250,140 and 10 ka, respectively. Analysis on characteristics of terraces show that five major terraces were mainly tectonic genesis. Therefore, five major terraces recorded five strong rising events in the Qilian Mountains during the past 830 ka. The ages of those rising events are about the same as those terraces formation. Sub-terraces, constituting a main terrace, were perhaps mainly formed by climatic changes.
基金Supported by the "973" Project (Grant No. 2005CB422001)the National Natural Science Foundation of China (Grant Nos. 40471016 and 40401007)the Doctoral Foundation of Ministry of Education, China (Grant No. 20030730017).
文摘The selection of high-resolution loess sections is needed in order to determine the climatic variability of the East Asian Monsoon during the last interglacial. Two sequences of S1 on the eastern and west-ern sides of the Liupan Mountain were both composed of five paleosol layers and four loess layers,indicating that there were five strong summer monsoon events and four strong winter monsoon events in MIS5. This corresponds with other records of the East Asian Monsoon,along with NGRIP and the North Atlantic records,implying that the climate of the Northern Hemisphere was very instable during the last interglacial. Two layers of paleosols and one layer of loess had developed during MIS5a and MIS5c. Compared with MIS5e,the climate in MIS5a and MIS5c fluctuated more intensively on a millen-nial scale,whereas the climate was relatively stable in MIS5e.