关键词: 中国沙漠, 碎屑长石矿物, 钾长石/钠长石比值, 末次冰期黄土, 青藏高原北缘

Abstract: Using an automated mineral identification technique (INCA-Mineral), we quantified the mineral compositions for the sediments that are collected from ten desert basins in East Asia. The mineralogical characteristics of felsic minerals were analyzed to determine the variation in spatial scale. Using the felsic component, e.g. quartz-plagioclase-K-feldspar compositions, results demonstrate that the desert basin along the Central Asian Orogenic Belt possess higher K-feldspar/albite ratios and higher Ca-plagioclase/quartz ratios, compared with that of the desert basins along northern Tibetan Plateau. The two end-member classification of desert sediments in East Asia was supported by previous studies using Nd-Sr-Hf isotopic fingerprinting method. The felsic mineralogical characteristic parameter showed similarity between the dust source deserts from the SDB and the glacial dusts on the Loess Plateau. These results strongly indicate that the northern Tibetan Plateau was the dominant dust material source for Chinese loess. Combined with the previous study by method of air mass back trajectory and geomorphology, the dust material contributions from the Central Asian Orogenic Belt was also potentially included via the long-distance wind transport.

Key words: Chinese deserts, detrital feldspars, K-feldspar/albite ratio, Chinese loess, northern Tibetan Plateau