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沙漠/沙地边缘和内部的古风成沙层、砂质古土壤是重建晚第四纪以来地表变化的直接地质证据。位于我国北方半干旱区的毛乌素沙地,其地表过程对气候变化响应敏感。在对毛乌素沙地进行野外拉网式调查以及前人研究的基础上,我们在沙地南部和东部的沙漠-黄土过渡带发现了大量的埋藏古风成沙丘沉积,指示了干冷期沙漠扩张的最南、东界限;沙地内部广泛发育的砂质古土壤则表明在气候相对暖湿期地表植被生长,土壤发育,沙丘基本被固定。对14个典型风成沙/黄土/古土壤沉积剖面进行了光释光年代学样品的采集和测试,结合空间分析和他人研究结果,发现在末次盛冰期(约26~16ka),毛乌素沙地的流动沙丘向南、东扩张,扩张距离现代边界约30~50km,面积扩大至少约10000km~2,占现代沙地面积的25%;在全新世大暖期(约9~5ka),毛乌索沙地大部分被固定,发育了较厚的砂质古土壤。研究结果揭示了毛乌素沙地的地表过程对末次盛冰期和全新世大暖期气候变化的直接响应。
Paleo-beast sand and sandy paleosol on the margin and interior of the desert / sand margin are direct geological evidences for reconstructing the surface changes since the late Quaternary. Located in the Mu Us desert in semi-arid northern China, its surface processes are sensitive to climate change. Based on a field survey of the Maowusu sand field and previous studies, we found a large number of burial paleo-dune sediments in the desert-loess transitional zone in the southern and eastern parts of the sand, indicating the most South and East boundaries of the sand; pale sandy soil widely developed within the sandland indicates that vegetation growth, soil development and sand dunes are basically fixed during the relatively warm and wet climate. A total of 14 typical aeolian / loess / paleosol sediment profiles were collected and tested for photoluminescence chronology. Based on the spatial analysis and other studies, it was found that during the last glaciation (about 26 ~ 16 ka) Of the mobile sand dune to the south and east expands and expands about 30 ~ 50km from the modern boundary with an area of at least about 10000km ~ 2, accounting for 25% of the modern sand area. During the Holocene (about 9 ~ 5ka) Sodagar most of the fixed, the development of a thick sandy ancient soil. The results reveal the direct response of the surface processes in the Mu Us desert to the climatic changes in the Last Glacial Maximum and the Holocene Holocene.