Distribution of Iron Oxides forms and their relation to B horizons development and soil – land scape from Al-Gaara depression

Abstract

Field and Labrotary investigation of four soil series at different londscape positions (Foot slope–Teo slope). From east to west in AL Gaara depression area, were made to determine the change in various forms of Iron oxides (Total, free and amorphous).(active Iron ratio (amorphous Iron / free Iron) and crystallinity ratio (free Iron – amorphous Iron / total Iron). Their genetic criteria were used to show the effect of landscape position on the amount and distribution of Iron forms.The result showed that the active Iron ratio increased in soil series teo slope at (143SCE, 132SCE) followed by soil series at foot slope (122SCE, 142SCE) where as the crystallinity ratio showed the difference due to informs of iron oxides bettwen haemitite iron which in creased with moisture content of soil and Geothite iron which increased with dry condition of soil. Topographic location and slope position forms effected on insitue pedogenic process. Their effects due to from Fluctuation in annual soil moisture drought period and internal soil drainge. furthermore results showed Negative and positive correlation. bettwen forms of iron oxides and their forms with some soil properties.