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在对玛曲高原东南部具有代表性的黄土-古土壤-风成砂沉积剖面进行常量、微量元素及地球化学风化参数分析的基础上,结合14 C测年结果,探讨了中晚全新世以来玛曲高原的化学风化过程。结果表明:(1)不同地化学元素在剖面中的化学活性表现出明显的差异性,常量元素Ca、Si、Na以强烈迁移淋失为主,Fe、Mg则表现为明显富集;元素活动性及迁移顺序为Ca>Si>Na>Al>K>Fe>Mg;常量元素的迁移特征表明玛曲高原处于脱Ca、Na的初期化学风化阶段;微量元素除Sr迁移淋失显著外,Cu、Mn、Zn均呈现出强富集特征。(2)根据典型地化学元素记录的冷干-凉润-凉干-温湿的气候变化过程,结合化学风化指标将玛曲高原中晚全新世以来的化学风化过程划分为3.8ka BP以前的风化较弱期、3.8~3.5ka BP风化较强期、3.5~1.6ka BP风化减弱期和1.6ka BP以来的风化增强期4个阶段。
Based on the analysis of the constitutive, trace element and geochemical weathering parameters of the representative loess-paleosol-aeolian sand sedimentary profiles in the southeastern Maqu plateau, Chemical weathering of Maqu Plateau. The results show that: (1) The chemical activities of different chemical elements show obvious differences in the profiles. The major elements of Ca, Si and Na are strongly leaching and leaching while Fe and Mg are obviously enriched. The activities of elements The migration characteristics of the major elements show that the Maqu Plateau is in the initial chemical weathering stage of removing Ca and Na; the leaching of trace elements except Sr is significant, while the Cu Mn and Zn show strong enrichment characteristics. (2) The chemical weathering process of cold-dry-cool-dry-warm-humid climate, which is typically recorded by chemical elements, is combined with the chemical weathering indicators to divide the chemical weathering process in the mid-late Holocene in the Maqu Plateau into 3.8ka BP BP Weathering weaker period, 3.8 ~ 3.5ka BP weathering strong period, 3.5 ~ 1.6ka BP weathering weakened period and 1.6ka BP weathering enhanced since 4 stages.