Geochemical Detection of Soil Discontinuities in a Relatively Stable Terrain: Wonu, South-West Nigeria

Abstract

Movement of soil materials resulting in transported overburden occur in relatively stable terrains as described from the Wonu area of South-West Nigeria. The effect of such transported soils may be serious in pedogeochemical studies as they could lead to false anomalies, masked anomalies and incorrect bedrock identification during geological mapping in highly weathered terrains. Several techniques and parameters have been successfully used to detect discontinuities in soil. A lot of these are based on ‘abrupt changes’ expressed by a departure in depth trends mostly physical between zones of otherwise relative uniformity. This study shows that plots of bases/alumina versus silica/alumina from geochemical analysis can be used to separate the transported soil material from that of the soil formed in-situ.

Keywords: Lithologic discontinuities, pedogeochemistry, bedrock, anomalies, profile

DOI: 10.7176/JNSR/9-3-02