Further alteration induces the formation of smectite-likeminerals in the E eluvial horizon. Finally, the Siox content (Table 1) confirms that the formation of poorly-crystalline aluminosilicates (ITM) occurs when the concentration of organic acids is sufficiently low to allow the precipitation of Al with Si, as suggested by Ugolini and Dahlgren (1987) in the fulvate bicarbonate theory of podzolization.