The massif of Kambusi, located about 30 km northwest of Bukavu, is made up of two intrusive plates: microgranite to the south and microsyenite to the north. These plates were emplaced during the Cambrian.The microsyenite is characterized essentially by the association of quartz, perthites, albite + K-feldspar, olivine, hedenbergite, edenitic hornblende, iron-rich biotite, ilmenite, and fluorine. The microgranite is distinguishable from the microsyenite by an absence of olivine, pyroxene, and fluorine, a relative richness of quartz and amphibole, and a scarcity of feldspar in the modal composition.These magmas are typically alkaline (some rocks show a hyperalkaline tendency) and were emplaced at a shallow depth under low values of graphic and graphic and high T (> 890 °C). They are considered to mark the relaxation stage typifying the change of tectonic regime that took place at the end of the Panafrican.

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