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对玛曲高原具有代表性的黄土-古土壤-风成砂剖面(OL剖面)常量元素氧化物含量及其比值的地球化学特征分析表明:(1)常量元素氧化物总含量为91.93%且SiO2(67.93%)>Al2O3(11.2%)>Fe2O3(3.97%)>CaO(3.76%)>K2O(2.16%)>Na2O(1.81%)>MgO(1.1%);(2)玛曲高原处于较弱的脱Ca、Na初级风化阶段,并伴有碳酸盐的淋失;(3)玛曲高原的气候经历了冷干-凉润-温湿-凉干的冷暖旋回。依据常量元素氧化物含量及其比值揭示的环境特征并结合14 C测年将玛曲高原中晚全新世以来的环境演变划分为4.6ka BP以前的风沙活动强烈期、4.6~4.3ka BP的风沙活动较弱期、4.3~0.3ka BP的固结成壤期和0.3ka BP至今的风沙活动增强期4个阶段。
The results show that: (1) The total content of oxides of major elements is 91.93% and the content of SiO2 in the loess-paleosol-aeolian sand profile (OL section) (67.93%)> Al2O3 (11.2%)> Fe2O3 (3.97%)> CaO (3.76%)> K2O 2.16%> Na2O 1.81% MgO 1.1% (3) The climate in the Maqu Plateau experienced cold-warm-cool-warm-humid-dry-cool warm-and-cold cycle. Based on the environmental characteristics revealed by the contents and ratios of the oxides of major elements and their correlation with the 14 C dating, the environmental evolution since mid-late Holocene in the Maqu Plateau was divided into the strong aeolian activities before 4.6 ka BP, In the weaker period, 4.3 ~ 0.3ka BP consolidation period into the soil and 0.3ka BP so far sandstorm activity enhanced four stages.