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Research Journal of Earth and Planetary Studies Vol 1.(2) pp.033 – 045 December 2011

Available online http://www.globalresearchjournals.org/?a=journal&id=rjeps

Copyright ©2011 Global Research Journals

Full Length Research Paper

STRATIGRAPHY OF IMOBI AND ENVIRONS, SOUTHWESTERN NIGERIA

Ikhane, P. R, *Omosanya, K O Alaka, A., O

 Department of Earth Sciences, Olabisi Onabanjo University, PMB 2002, Ago-Iwoye Nigeria .

*Corresponding Author’s E-Mail: kamaloomosanya@yahoo.com, Tel: +2348034454405

Accepted 20th November 2011

Abstract

Electrical resistivity survey was used to characterize the subsurface stratigraphy of Imobi and its environs with the aim of identifying the geoelectric layers, sedimentary facies, and deciphering the possible environment of deposition.

Eight Vertical Electrical Sounding (1D) with a maximum electrode spacing of 700m and 1000m using Schlumberger array; and an Electrical Resistivity Imaging (ERI) along two profiles of 300m each using Wenner array were used in this work; the result obtained was interpreted with WINGLINK and DIPROWIN software respectively.

The inferred stratigraphy of the area exhibits an alternating sandstone facies overlain by thin clayey sand horizon and the topsoil; the five sandstone electro-facies include ferruginised, tar-bearing, saline water saturated, water-saturated and compacted sandstone. With resistivity value ranging from 60Ωm- 99,689Ωm and thickness value of 1.06m- 210.34m; the topsoil is highly resistive and sandy with the thin clayey sand horizon restricted to the SW part of the area.

The stratigraphy of the area indicates a non-marine repetitive depositional sequence characteristic of the Afowo formation of the Eastern Dahomey Basin.

Keywords: Stratigraphy, Sandstone, Facies, Dahomey, Resistivity.