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对中国东北地区科尔沁沙地13个风成沙剖面和3个黄土剖面进行了研究,测试分析了黑色砂质土壤和下伏古风成沙的OSI年龄及粒度、磁化率、色度数据;OSL测年获得的古风成沙数据位于末次冰期晚期-全新世期间(13~10ka),小于26.5~19.Oka的末次冰盛期时段。末次冰盛期干冷气候背景下沙丘持续不断的活化翻动,风成沙在进入全新世气候转暖后才被固定,沙地内全新世黑色砂质土壤下伏的疏松流沙为末次冰盛期产物,其分布范围可代表末次冰盛期流动沙丘的分布范围。现今科尔沁沙地面积约为42000km~2,活动沙丘面积约占10%。在末次冰盛期不仅原固定沙丘活化,沙质平原与部分甸子也被流沙覆盖,面积约85000km~2,活动沙丘或流沙面积相对目前扩大了约20倍。末次冰盛期沙地活化扩张的控制因素主要有两方面:一方面冰期气候干旱寒冷,降水减少,地表植被覆盖下降,地表松散沉积物遭受风力剥蚀而活化成流沙;另一方面科尔沁沙地内部水系发育,河流流经途中会沉积大量松散物质。在冰期干冷环境下,河流水位下降,河流沙暴露并遭受风蚀改造,为流沙扩张提供物源,沙漠沿西拉木伦河流域扩展。
The 13 aeolian sand profiles and 3 loess profiles of Horqin sandy land in northeastern China were studied. The OSI ages, grain size, magnetic susceptibility and chromaticity data of black sandy soil and the underlying paleosol were measured and analyzed. OSL The palaeoclimate data obtained in the past are located in the last ice age period during the last Ice Age - Holocene (13 ~ 10ka), less than 26.5 ~ 19. Oka. During the last ice age, the sand dunes in the dry and cool climate continued to flip, and the aeolian sand was not fixed until the Holocene climate warmed. The loose loose sandstones underlying the Holocene black sandy soil in the sandstones were the product of the last ice age, Its distribution range can represent the distribution range of mobile sand dunes during the last ice age. Now Horqin sandy land area is about 42000km ~ 2, active dune area accounts for about 10%. During the last ice-age, not only the original fixed sand dunes were activated, but also the sandy plains and some dianzi were covered by quicksand, with an area of 85000km ~ 2. The area of active sand dunes or quicksand was expanded by about 20 times. The controlling factors for the activation and expansion of sandy land during the last ice age are mainly two aspects: on the one hand, the cold climate in the glacial climate is cold, precipitation decreases, the vegetation cover on the surface declines, the loosened sediments on the surface are activated by wind erosion to become quicksand; on the other hand, Water system development, river flow will be deposited on the way a lot of loose material. In dry and cold glaciers, river water levels drop, river sand is exposed and wind erosion is altered, providing a source for quicksand expansion, and the desert extends along the Xiluramun River.