Genesis of Soils from Mafic and Ultramafic Rocks in Southeast Ingassana Hills Complex, Blue Nile State, Sudan

Abstract

Abstract Ingassana Hills Complex composed of greatly weathered rocks forming clays and laterite. Chemical analyses show a depletion of high soluble elements such as Si4+, K+, Na+, Ca2+, Mg2+, Fe2+ etc., and enrichment of Al3+, Fe3+, Ti4+, H2O+ etc., in their weathering products . Silica, potassium and others, beside the formation of economic mineral deposits like gold, pyrite, and chalcopyrite were present within the shear zone in the area. Soil profiles have shown gain of ferric iron, titanium and alumina and other most resistant elements on progressive weathering. The meager light minerals are quartz and feldspar and the magnetic and nonmagnetic are distributed in different percentages such as chromite (20%-75%), galena (9%-70%), pyrite (10%-20%), hematite (10%-40%), copper (5%-20%) associated with zircon, gold, chalcopyrite, tourmaline, cinnabar and talc.