Abstract

Termitarian, the epigeal biogenic structure constructed by termites are widespread in the forest and derived savannah regions of Nigeria. Soil modification, with particular focus on the mineralogy, variation in geochemical composition and geotechnical properties of termite mound soil samples collected from nine location in the Ika area, Delta State of Nigeria are the objectives of this report. The major elements geochemical composition of the termite mound soil samples determined by XRF was found to be mainly SiO₂ (40.25%), Fe₂O₃ (29.27%), Al₂O₃ (24.25%) and T₁O₂ (4.27%). The other major elements; CaO, MnO, MgO, Na₂O and P₂O₅ were present at less than 1%. Trace element compositions of the termite mound soil samples were found to be Cr (8.20- 23.10 mg.kg^-1), Pb (3.95- 13.85 mg.kg^-1); Cu (2.75-12.00 mg.kg^-1), Zn (3.60-9.60 mg.kg^-1) and Cd (1.90-3.15 mg.kg^-1). Minerological composition of the termite mound soil samples determined by XRD revealed significant hematatic composition with a range of 60.17-83.78%, antigorite (5.24 -24.17%) and quartz (7.14-14.67%). Anthophylite (19.92%) was found in only one termite mound soil samples. The geotechnical tests carried out on the termite mound soil samples included: Grain size, atterberg limit, compaction and triaxial tests. The range of values of the determined properties: Uniformity coefficient (3.75-7.50), coefficient of curvature (0.20-2.70), plasticity index (10.83-28.45%), plasticity limit (13.47- 19.57%), optimium moisture content (7.20- 15.40%), maximum dry density (1.72-2.10g.cm^-3), angles of friction (2.83- 24.77°) and cohesion of up to about 50.11 KN.m², suggest that the termite mound soil may have limited application in soil stabilization and concrete works.

Key words: Ika, geotechnical, geochemical, termite, mound.