Iron Oxides Minerals in Soils Derived from Different Parent Materials

Abstract

The knowledge on soil iron oxides morphology and crystallization is important for the management of nutrients especially phosphorus. The objectives of the study were to determine the iron oxides minerals in Pothwar uplands. In the study one soil from each parent material (loess, alluvium, sandstone and shale) was selected. Selected clay samples suspensions were observed under transmission electron microscope. Ferrihydrite was common iron oxide mineral observed in all selected parent material soils at different level of crystallinity. Ferrihydrite was observed in scattered granules and also as aggregates or clusters. Crystalline iron oxides hematite and lepidocrocite was observed only in shale derived Murree soil. Mica and Rutile were the inorganic crystalline material on which masses of ferrihydrite was scattered.  Energy dispersive spectra of scattered ferrihydrite masses   show it has more   phosphorus than   lepidocrocite and   hematite. The study concludes that ferrihydrite was the major iron oxides mineral in all selected parent material soils while shale derived soil also had lithogenic hematite and lepidocrocite.