Pedogenesis, weathering status and mineralogy of the soils on ironstone plateaux (laterites), Sokoto Nigeria

Abstract

Soils on four ironstone plateau near kalalawa, Adarawa, Bissalam and Tureta in Sokoto State were studied with the aim of a ascertaining their genesis, weathering status and soil mineral content. Morphological studies, total elemental analysis and X-ray diffraction were conducted for this purpose. The soils were found to have formed on weathered geological materials overlain by indurated ironstone crust. The geological weathered materials are Gwandu/kalambaina, Gwandu, Dange/Wurno and Gundumi formation on kalambaina, Adarawa, Bissalam and Tureta ironstone plateau respectively. The soils have good structural development and pronounced textural differentiation. The soils are well developed in terms of pedogenic processes (humification, mineralization, lessivation, homogenization and leaching) that have operated and are still operating to form the soils. Result of the silt/clay ratio, sesquioxide ratio and total Potassium, revealed a low weathering potential of the soils making them moderately weathered soils. The dominant mineral identified in the soils is quartz with kaolinite, feldspar and chlorite in trace amounts.