Crustal structure of southern Burkina Faso inferred from magnetotelluric, gravity and magnetic data

Le Pape, F. and Jones, A.G. and Jessell, M.W. and Perrouty, S. and Gallardo, L.A. and Baratoux, L. and Hogg, C. and Siebenaller, L. and Touré, A. and Ouiya, P. and Boren, G. (2017) Crustal structure of southern Burkina Faso inferred from magnetotelluric, gravity and magnetic data. Precambrian Research, 300. pp. 261-272. ISSN 0301-9268 (Accepted Version)

Text LePape_2017_PrecamR_accepted_Vers.pdf - Accepted Version Download (3MB)

Abstract

Understanding the architecture of the West African craton at depth is essential to be able to reconstruct its evolution. Our study focuses on the crustal imaging of structures and geometries characterizing the crust of the Leo-Man shield with broadband and long period magnetotelluric data collected in southern Burkina Faso and covering a 220 km long profile. The resulting 3D resistivity crustal model highlights the distribution of the granite-greenstone assemblages with depth showing excellent correlation with mapped surficial lithologies. The whole crust of southern Burkina Faso is resistive, with lateral as opposed to vertical major resistivity contrasts, reflecting the location of major-scale shear zones characterizing this part of the Baoulé-Mossi domain. Ground gravity data acquired along the same line as the MT data were also modeled and show relatively good correspondence with the resistivity model. The new resistivity and gravity models compared with results from joint inversion of gravity and aeromagnetic data highlight significant changes between the greenstone belts and granitoid domains along the profile. The comparison of the geophysics with the geology enables us to define new depth constraints of the main tectonic features in the area. The observed large scale dipping shear zones favour the model of crustal building through major parallel thrust faults.

Item Type:	Article
Uncontrolled Keywords:	West African craton, Burkina Faso, magnetotellurics, gravity, magnetization, joint inversion
Divisions:	School of Cosmics Physics > Geophysics
Date Deposited:	19 Apr 2021 13:19
Last Modified:	14 Dec 2022 13:41
URI:	https://dair.dias.ie/id/eprint/1118

Actions (login required)

View Item

Downloads