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利用光释光测年技术对科尔沁沙地的7个风成砂-砂质古土壤剖面进行年代测试,结合地层和孢粉分析得到晚冰期以来科尔沁沙地的演化过程如下:16～10 ka B.P.,风成砂出现,沙地活化;10～3 ka B.P.,砂质古土壤发育,沙地固定;约3 ka B.P.前后,风成砂出现,沙地活化;3 ka B.P.至今,多层弱发育砂质古土壤和风成砂的交替出现,指示晚全新世科尔沁沙地的多次固定与活化;从约4～2 ka B.P.,沙地环境由草甸草原逐渐退化为典型草原。分析表明,3 ka B.P.以前科尔沁沙地的演化完全受气候变化的控制,之后(尤其是辽代以后)人类活动的影响日益增强。
The ages of seven aeolian sandy-sandy paleosol profiles in Horqin sandy land were measured by using photoluminescence dating technique. The evolution of Horqin Sandy Land after the glacial ice age was obtained by combining the stratigraphic and sporopollen analysis. The evolution process of Horqin sandy land is as follows: 16 ~ 10 ka BP , Aeolian sand appeared and the sand was activated. In the past 10 ka BP, the sandy paleosol developed and the sandy land was fixed. The aeolian sand appeared and the sand was activated before and after about 3 ka BP. Since 3 ka BP, Alternate occurrence of sandy paleosol and aeolian sand indicates multiple fixation and activation of Horqin Sandy Land in the late Holocene. From about 4 to 2 ka BP, the sandy environment gradually degenerated from meadow steppe into typical steppe. The analysis shows that the evolution of Horqin Sandy Land was totally under the control of climate change after 3 ka B.P. The influence of human activities increased especially after the Liao Dynasty.