Abstract

Pedons formed from hill creep and hill wash soils along an aberrant toposequence associated with a rock hill were studied to understand the morphogenetic properties influencing soil formation in Ile-Ife area, South Western Nigeria. Soil morphology, physical (including sand fractions), and chemical properties were used to characterize and classify the soils. The results showed that lithologic discontinuities were expressed by presence of stone lines, abrupt changes in soil texture/sand sub-fractions and accumulation of cations in surface than sub-surface pedons. The active pedogenic processes influencing soil formation include, transportation and deposition, cummulation and homogenization. Regolith types formed include” colluvio-residuum, colluviums and alluvium underlaid with soil residuum. Pedons 1 and 2 were classified as dystrochrepts (Dystric Cambisols). Pedon 3 was classified as Ultic Udarents (Lixic Arenosols) pedons 4 and 5 are Typic Rhodudults (Rhodic Lixisol) and Plinthudults (Plinthosols) while Pedon 6 was classified as Anthropic Quartzipsamments.

Key words: Lithologic discontinuity, morpho-genetic characterization, soil classification, rock hill, regolith types.