This research focuses on the study of mineral parageneses of metamorphites that outcrop in the Nganda-Tsundi region and its surroundings located in the territory of Tshela, in order to obtain coherent information regarding the degrees of metamorphism that have contributed to the transformation of pre-existing rocks. The compilation of field (macroscopic analysis), laboratory results and previous work results revealed seven main petrographic facies in the study area: namely the biotitoschist, chloritochist, amphibolite, quartzophyllade, sericitoschist, garnet metaquartzite and graphitic shale. Mineralogical assemblages enabled us to distinguish three degrees of metamorphism in the study area: low-grade, medium-grade and high-grade. By combining structural data, such as the schistosities observed in the field and during microscopic in thin sections observations, with these last mineralogical observations, we can conclude that the rocks of our study area were affected by two distinct orogenic events namely: the Tadilian orogeny of Proterozoic age which is responsible for two types of schistosity which affected the chloritoschists and the West-Congolian Neoproterozoic orogeny, is responsible for a single schistosity affecting the other petrographic facies (biotitoschist, amphibolite, quartzophyllade, sericitoschist, metaquartzite and graphitic schist).

This work consists of a sedimentological and paleoenvironment study of the carbonate rocks of the Mbuji-Mayi Supergroup dated to the Neoproterozoic of the Bena Kabongo quarries. Macroscopically, two lithofacies have been determined, namely: limestone and dolomite. Field observations show us that the base of the sequence is dominated by dark fine-grained limestones. The summit part is represented by fine-grained gray limestones that alternate with brownish dolomite. Based on seven thin sections, a microscopic observation was carried out and allowed us to detect three microfacies, namely: intrasparites, intramicrites and intraclastics, all representing a standard sequence of the sedimentary series. This sequence shows the evolution of the deposit going from a subtidal zone to an intertidal zone. Analysis of the microfacies of the sequence shows that the strata were accumulated on an internal ramp in the shallower and more oxidizing conditions with stromatolitic flora.