摘要:
提要：成都平原晚更新世成都粘土地球化学分析表明，不同剖面样品的化学组成具有较好的一致性，以SiO2（平均75.24%）、Al2O3（平均14.12%）、Fe2O3（平均5.81%）为主，地球化学特征与UCC基本相似。与北方黄土相比，成都粘土具有较高的TiO2/Al2O3、Zr/Al、Zr/Ti和Y/Al以及较低的Eu/Eu?鄢、LaN/SmN和LaN/YbN比值，这些特征与成都平原第四系深层土壤样品组成一致，表明成都粘土来源于当地，与北方黄土物源不同。成都粘土CIA平均值为78.59，高于北方黄土平均值（69.34），经历了中期的K迁移阶段，在风化过程中Ca、Na、Mg和K是主要的活动性元素。与北方黄土相比，成都粘土Na、Mg、K和Ca亏损较大，表明经历了更强的化学风化。
Abstract:
Abstract：The chemical composition of late Pleistocene Chengdu clay in Chengdu plain shows that SiO2 (75.24% on average), Fe2O3 (14.12% on average) and Al2O3 (5.81% on average) are dominant chemical compositions, Chengdu clay has an overall similarity in geochemical characteristics to the UCC. In comparison with the loess of northern China, Chengdu clay has higher TiO2/Al2O3, Zr/Al, Zr/Ti and Y/Al ratios, and lower Eu/Eu?鄢, LaN/SmN and LaN/YbN ratios. These features coincide with those of the Quaternary deep soil in Chengdu plain, which suggests local sources for the Chengdu clay in this region; nevertheless, Chengdu clay is quite different from the loess of northern China. The average chemical index of alteration (CIA) of Chengdu clay is 78.59, higher than that of the loess of northern China. Chengdu clay has experienced the intermediate K removal weathering stage, and Ca, Na, Mg and K seem to have been the main mobile elements in the weathering process. In comparison with the loess of northern China, Chengdu clay has greater depletion of Na, Mg, K and Ca, indicating a stronger weathering intensity.
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