Exploratory Environmental Science Research
Volume 2 – Issue 1 – 2021
Original Research Article
The Use Of Magnetic And Geochemical Proxies To Evaluate Pedogenesis And Chemical Weathering Intensity In A 1.2m Soil Profile In Jalingo, Nigeria
Maxwell O. Kanu
Department of Physics, Faculty of Science, Taraba State University, P.M. B. 1167, Jalingo, Taraba State, (NIGERIA)
PAGE NO: 109-126
ABSTRACT – DOI: https://dx.doi.org/10.47204/EESR.2.1.2021.109-126
Magnetic and geochemical proxies have been used to evaluate pedogenesis and chemical weathering intensity in a 1.2 m soil profile in Jalingo, NE Nigeria. The results of the magnetic parameters indicates that the magnetic signal of the soil is mainly influenced by ferrimagnetic, low coercivity minerals with only minor fractions contributed by antiferromagnetic minerals like hematite. The magnitude of the ferrimagnetic minerals is highest within 30 – ~100 cm of the soil profile which is dominated by superparamagnetic (SP) grains. It seems the pedogenic processes in the profile led to the relative increase in fine – grained ferrimagnetic SP grains and depletion of antiferromagnetic minerals. Geochemical parameters indicated that chemical weathering had led to the removal of easily mobile elements (K, Ca, Si, and Mn) and the enrichment of immobile elements (Al, Fe, Zn, Ti and Pb) in soils, suggesting higher pedogenic intensity within this soil profiles. The result also established that chemical weathering intensity and pedogenesis is greater within ~ 40 – 100 cm of the profile. CIA measurement indicated moderate to high chemical weathering in the profile. Chemical weathering and pedogenesis resulted in distortion of the particle size of soils, retaining the clay size fractions and removing the silt fractions. Iron oxides and ferromagnetic minerals are observed to increase as chemical weathering and soil formation increases in the studied soil profile. The study successfully established that rock magnetic methods could be an effective tool to evaluate the degree of pedogenesis and weathering intensities.