中国白浆土研究Ⅱ．无定形铁、锰、铝氧化物特性及其元素地球化学分异

STUDY ON ALBIC SOILS IN CHINA Ⅱ.PROPERTIES AND GEOCHEMICAL VARIABITY OF AMORPHOUS IRON,MANGANESE AND ALUMINIUM OXIDES

本文主要研究了白浆土中无定形态铁、锰、铝氧化物特性及其元素的地球化学特征。结果表明：（１）游离态、活性态及络合态的铁、锰、铝氧化物都向着粘粒中富集。其中游离态及活性态中，Ａｌ＿２Ｏ＿３富集最强烈，Ｆｅ＿２Ｏ＿３次之，ＭｎＯ最弱。（２）铁、锰、铝氧化物的活性是ＭｎＯ高于Ｆｅ＿２Ｏ＿３，而Ａｌ＿２Ｏ＿３主要取决于ｐＨ值，同时也受其它因素的影响。ＭｎＯ和Ｆｅ＿２Ｏ＿３在活性上的差异，不仅取决于两者在标准氧化还原电位的差异上，还与两者和有机质形成络合物的能力有关。（３）白浆土中有机质含量与结合态氧化物含量之间的相关关系特性，以及络合物中金属原子与碳原子比值（Ｍ／Ｃ）的特点表明，络合态淋溶作用在白浆土形成中不但存在，而且还起着一定的作用.

Four typical profiles of albic soils in China were collected to study the proper-ties and geochemical variability of amorphous oxides collected to study the proper-ties and geochemical variability of amorphous oxides of iron,manganese and aluminum.The mian results are summarized as follows:1.The free,activated and chelated oxides of iron,manganese and aluminumwere enriched in clay.Among the free and activated oxides enriched, Al_2O_3 was thehighest. Fe_2O_3 the second,and MnO the lowest. Among the chelated oxides, MnOwas the highest,Al_2O_3 the second,the Fe_2O_3 the lowest.2. The activity of mangance oxide was greater than that of iron oxide whichresulted from not only the difference of the standard redox potential of the twometals but also the capacity of chelation by the organic mater.The activity of alu-minum oxide depends on the pH and some other factors of the soil.3.The correlation between the content of organic matter and the content ofchelated metals and the metal/carbon ratio of chelates proved that cheluviation exi-ted and play a certain role in the formation of albic soils.