Geophysical Characterization of Candidate Rock Contacts Within Igarra Area, South-western Nigeria
  • Author(s): MUSLIM B. AMINU
  • Paper ID: 1702691
  • Page: 144-153
  • Published Date: 17-06-2021
  • Published In: Iconic Research And Engineering Journals
  • Publisher: IRE Journals
  • e-ISSN: 2456-8880
  • Volume/Issue: Volume 4 Issue 11 May-2021
Abstract

The aim of this paper is to present the application and interpretation of multi-method nearsurface geophysical surveys including electrical resistivity imaging, total-field ground magnetic prospecting and ground electrical conductivity surveying to delineate lateral rock contacts in Igarra area in Southwestern Nigeria, especially in locations of poor rock exposure. The multi-method technique has practical application in detecting fracture zones for groundwater resource development; besides, the usefulness in improving the placement of locations of rock contacts accurately on geological maps. In the Igarra area, the lateral lithologic contacts have resulted from the metamorphism and re-crystallisation of initial contacts between sedimentary rocks, and also from late-stage granitic intrusions into pre-existing meta-sediments. Three geophysical profiles were taken in the study area. The profiles traverse contacts involving a transition from metaconglomerate-to-intrusive granite and two re-crystallized and rotated sedimentary boundaries; a metaconglomerate-to-quartzite and a phyllite-to-metaconglomerate boundary. Each boundary type yielded consistent diagnostic ground electrical resistivity and total field magnetic anomalies indicative of either the presence of groundwater or magnetic mineral concentrations at the contacts. The metaconglomerate-to-quartzite contact presented an electrical conductivity anomaly. However, the metaconglomerate-to-intrusive granite and the phyllite-to-metaconglomerate boundary did not present any electrical conductivity anomaly. The delineated rock contacts are potential supplementary source of groundwater and possible locations for the concentration of valuable minerals in the Igarra area.

Keywords

Lithologic contacts, near surface geophysics, low aperture fractures, groundwater, Igarra Schist belt

Citations

IRE Journals:
MUSLIM B. AMINU "Geophysical Characterization of Candidate Rock Contacts Within Igarra Area, South-western Nigeria" Iconic Research And Engineering Journals Volume 4 Issue 11 2021 Page 144-153

IEEE:
MUSLIM B. AMINU "Geophysical Characterization of Candidate Rock Contacts Within Igarra Area, South-western Nigeria" Iconic Research And Engineering Journals, 4(11)