MUKONKOLE MUKONKOLE Patrick1*, ILITO LOFONGO Daddy Patrick1, KANDA NKULA Valentin1, 2, MUANZA KANT Patrick1, MUILU MAYALA Daudet1, PINGANAY SABUA1.

Preliminary metallogenic study of the green rocks of Gangila in the West Congo Belt (WCB) in Democratic Republic of Congo

The green rocks of Gangila are located along the Mvuzi River in the territory of Seke-Banza. The collected samples were subjected to petrographic studies (thin sections and polished sections) and chemical analyzes to determine the genetic environment of these rocks as well as the origin of the brines having traveled these metamorphites. The results of the chemical analyzes of the major and trace elements carried out on these rock samples and on the quartz vein allowed us, with the help of DTI (Ternary Diagram of Intiomale) to conclude that these rocks originated in a "Distensive regime" and the brines circulating in these Gangila metamorphites have a "mixed origin" at a temperature of 347°C which is characteristic of the "pleothermal stage" according to the geothermometric scale Ca-Ti. Such a temperature would be related to oceanic opening and mobilizing Kuroko type fluids. The so-called mixed solutions result from the mixing of supergene fluids with hypogenous fluids from subalkaline granitoids. Metalliferous minerals are disseminated on these metamorphites and offer no preference for any type of rock. Disseminations of chalcopyrite observed under a microscope on the polished sections of these green rocks show that chalcopyrite mineralization is ubiquitous and results from a mixture of circulating solutions in the metamorphites. These metals should therefore come from the metamorphites themselves and are therefore "indigenous". Téléchargé l'article