Genesis of Mayouom kaolin deposit (western Cameroon): Fid-Bau Portal

Genesis of Mayouom kaolin deposit (western Cameroon)

Njoya, A. / Nkoumbou, C. / Grosbois, C. / Njopwouo, D. / Njoya, D. / Courtin-Nomade, A. / Yvon, J. / Martin, F.

AbstractGeological, mineralogical and geochemical studies were carried out on Mayouom kaolin deposit located within a mylonitic shear zone about 30 km north of Foumban town (western Cameroon), in order to define the ore genesis and its economic interest. Two facies (sandy kaolin and sand-poor kaolin) were characterised by different techniques: description of outcrops and pits, X-ray diffraction, differential scanning calorimetric and thermogravimetric analyses, scanning electron microscopy, Fourier transform infrared spectrometry and bulk chemical analyses. Sand-poor kaolin (76–85% kaolinite and 2–9% quartz) forms 1 to 2 m thick veins which crosscut sandy kaolin (48–59% kaolinite and 36–47% quartz). All the samples have the following mineral phases in common, close to an advanced argillic alteration system: kaolinite+quartz+illite/muscovite+anatase±hematite±Ba, Sr-hydroxyapatite±zircon±pyrite±florencite. Both sandy and sand-poor kaolins present kaolinite mineral with a homogeneous shape and a good crystallinity. Results from the different analytical techniques point out a hydrothermal alteration of feldspar- and mica-rich rocks as petrogenetic origin of kaolins. Sandy kaolin comes from mylonite basement while sand-poor kaolin is related to the alteration of magmatic intrusive shape veins.Due to its high kaolinite content (up to 85%) and the low iron mineral content (<1.5%), Mayouom kaolin is a suitable raw material for white burning industrial clays. Moreover, the advanced argillic alteration mineral assemblage can be considered as a rough indicator for exploration of related ores in neighbouring areas and along the northern Foumban shear zone.