The formations of this region are essentially metamorphic Granit-Gneissic of which the term granitic is descended of the granitization-migmatization of Kimezien. Two tectonic periods have been demonstrated by double schistosities noticed to the level of the micas. The geochronology of these formations will be able to bring more precision on the age of these formations and that has the end will confirm or will invalidate the thesis to evoke in this survey.

This cartographic survey has been done from the samples of cores of polls achieved on longitudinal and transverse profiles as well as by the modelling, appropriated precisely in the concession of the mining of Bakwanga on the massif 12. Of these data of polls, we could achieve a cartographic survey and deduct the structure of this massive kimberlitic under survey. Let’s note that most polls on this massif, met the sand, sandstone, the epiclastic kimberlite, the xenokimberlite, the massive kimberlite and the limestone. In a general manner, to part the limestone, the dolomite, sandstone and the sand, three facies kimberlitics has been put in evidence in this publication and it, according to the percentage in kimberlitics elements, it is about of: - The kimberlite very tender epiclastic (0-25% of kimberlitic elements). - The little strengthened xenokimberlite (25-50% of kimberlitic elements). - The massive kimberlite (beyond 75% of kimberlitic elements).

In the city of Kinshasa, the poor management of waste (plastic bags, packaging, household waste and others) poses enormous problems of insalubrity and degradation of nature, thus causing the development of endermic diseases (malaria, typhoid, etc.). Despite the efforts made by the municipal authorities, this problem of insalubrity in the Congolese capital still remains. Good waste management through public trash cans will generate positive and negative impacts on the Kinshasa environment. On this, we propose in this study some strategies for the distribution of new locations according to the methods adopted. The data obtained in the field and the results of their analysis have made it possible to deduce that the rate of insalubrity has increased over the past six years due to poor waste management. To remedy this persistent problem, we ask the population of the District of Mont-Amba to properly manage their waste by installing garbage cans and to participate in community work. To the authorities, we are asking for strong awareness raising regarding waste management and the installation of public trash cans in appropriate places outside neighborhoods.

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.