Petrography and geophysical characterization of the newly discovered iron ore deposit in Makoure (Bidou-East), Nyong group, South Cameroon

Abstract

The Makoure's newly discovered iron deposit belongs to Nyong group. It is yet to be documented. Detailled field mapping, petrographic study, and ground magnetic geophysical surveys were used to characterize Makouré iron prospect. The lithology of Makouré is made up of gneiss, amphibolite, micaschist, orthogneiss, quartzite, iron formations and duricruts. The Makouré’s iron formations is a typical Banded Iron Formation (BIF). The rock is highly magnetic, weakly metamorphosed, with well expressed centimetric dark bands of magnetite alternating with light bands of silica. Magnetites are subhedral coarse grained (0.5 to 1.5 mm), while silica crystal are the smallest (less than 0.5 mm). The foliation of the Banded Iron Formation avreagely strikes N065°E and dips 70° toward the SSE. The rock exposures experienced brittle deformation, the fractures are sub-vertical and perpendicular to the foliation, in some place they form chlorites/sulphides veins. The recorded magnetic values vary from 32,000 to 34,000 nT. The dipole values higher than 33,100 nT are related to iron formations. The magnetic susceptibility vary from 0.0001 to 0.05 m3/kg. The strongly magnetic body is open at depth and along strike. The ore body is steeply dipping towards the East and seems to be structurally controlled, mostly when getting close to the surface. Drilling results should also be integrated in the remodelling of magnetic susceptibility to put constraints on the model.