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根据科尔沁沙地东部TL剖面磁化率、有机质、化学元素等气候代用指标的变化特征和14 C测年结果,分析和讨论了科尔沁沙地6ka BP以来的气候变化过程。实验数据显示,高频磁化率、低频磁化率、有机质、Al2O3含量变化趋势基本一致,且峰值段对应古土壤层,谷值段对应风成砂层。依据气候代用指标的变化将6ka BP以来科尔沁沙地气候变化分为3个阶段:Ⅰ.6.0～4.2ka BP,气候暖湿,夏季风逐渐增强,并占主导,冬季风较弱,与全新世大暖期对应,但存在百年尺度的气候波动,其中:6.0～5.6ka BP,5.6～5.4ka BP,4.9～4.2ka BP气候暖湿;5.6～5.5ka BP,5.4～4.9ka BP气候相对冷干。Ⅱ.4.2～1.3ka BP,气候相对暖湿,与上一阶段相比夏季风有所减弱,但仍强于冬季风,其间也存在次一级波动,3.7～3.6ka BP,3.4～1.3ka BP,气候相对暖湿,4.2～3.7ka BP,3.6～3.4ka BP气候相对干冷。Ⅲ.1.3～0.65ka BP以来,气候波动频繁,后期有向暖湿发展的趋势。总体而言,区域气候变化与全球具有较好的一致性。
According to the change characteristics of climatic proxies such as magnetic susceptibility, organic matter and chemical elements in the TL section of eastern Horqin sandy land and the 14 C dating results, the climate change process since 6 ka BP in Horqin sandy land was analyzed and discussed. Experimental data show that the trend of high frequency magnetic susceptibility, low frequency magnetic susceptibility, organic matter and Al2O3 content is basically the same, and the peak section corresponds to paleosol layer and valley section corresponding to aeolian sand layer. According to the change of climate proxy index, the climate change of Horqin Sandy Land since 6ka BP is divided into three stages: Ⅰ.6.0 ~ 4.2ka BP, the climate is warm and humid, the summer monsoon is gradually strengthened and dominated, the winter monsoon is weak, and the Holocene However, there is a century-scale climate fluctuation, of which: 6.0 ~ 5.6ka BP, 5.6 ~ 5.4ka BP, 4.9 ~ 4.2ka BP climate warm and wet; 5.6 ~ 5.5ka BP, 5.4 ~ 4.9ka BP climate is relatively cold dry. Ⅱ.4.2 ~ 1.3ka BP, the climate is relatively warm and humid. Compared with the previous stage, the summer monsoon weakened, but still stronger than the winter monsoon. There were also sub-first-order fluctuations, 3.7 ~ 3.6ka BP, 3.4 ~ 1.3ka BP, relatively warm and humid climate, 4.2 ~ 3.7ka BP, 3.6 ~ 3.4ka BP climate is relatively dry and cold. Ⅲ.1.3 ~ 0.65ka BP since climate change is frequent, the trend of warm and humid to the late development. In general, regional climate change has good global consistency.