Volume 19, Issue 2, February 2017, Pages 376–384
I. Chunga Chako1
1 Université Libre des Grands Lacs (ULGL/Bukavu), Département de Géologie, Faculté des Sciences, RD Congo
Original language: French
Copyright © 2017 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
The petrologic study of gneiss of Bunhyakiri in the South –Kivu province in the Democratic Republic of Congo. The following lithologies were identfied: the gneiss was subdivised in gneiss “oeillés”, granitics gneiss and leptyni, and the pegmatit was subdivised in pegmatit contens tourmalin and pegmatit contens biotit. The chemical analysis had shown that the gneiss of Bulambika was born from metamorphic evolution of medium and acid rocks (granit, granodiorit, tonalit). This lasts are peraluminous and belong to one magmatic series which is calcoalcalin sery. It means that they are magmatic rocks which come from mantel and they were formed in subduction context. These formations are, to the mineralogic point of view, rich in feldspaths (±55% of proportion) where the albit dominate. They are belonging to the class of Kibarian granitoids of the group of Bitale.
Author Keywords: Petrology, Gneiss, Pegmatite, Mineralogical composition, Bunyakiri.
I. Chunga Chako1
1 Université Libre des Grands Lacs (ULGL/Bukavu), Département de Géologie, Faculté des Sciences, RD Congo
Original language: French
Copyright © 2017 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
The petrologic study of gneiss of Bunhyakiri in the South –Kivu province in the Democratic Republic of Congo. The following lithologies were identfied: the gneiss was subdivised in gneiss “oeillés”, granitics gneiss and leptyni, and the pegmatit was subdivised in pegmatit contens tourmalin and pegmatit contens biotit. The chemical analysis had shown that the gneiss of Bulambika was born from metamorphic evolution of medium and acid rocks (granit, granodiorit, tonalit). This lasts are peraluminous and belong to one magmatic series which is calcoalcalin sery. It means that they are magmatic rocks which come from mantel and they were formed in subduction context. These formations are, to the mineralogic point of view, rich in feldspaths (±55% of proportion) where the albit dominate. They are belonging to the class of Kibarian granitoids of the group of Bitale.
Author Keywords: Petrology, Gneiss, Pegmatite, Mineralogical composition, Bunyakiri.
Abstract: (french)
Une Etude pétrologique des gneiss de Bunyakiri dans la province du Sud Kivu, en République Démocratique du Congo a été effectuée. Les formations suivantes ont été inventoriées: les gneiss subdivisés en gneiss oeillés, gneiss granitiques et leptynite, et les pegmatites subdivisées en pegmatite à tourmaline et pegmatite à biotite. Les analyses chimiques ont révélé que les gneiss de Bulambika proviennent d’une évolution métamorphique des roches magmatiques intermédiaires et acides dont le granite, le grano-diorite et la tonalité. Ces dernières sont peralumineuses et appartiennent à une série calco-alcaline, c’est-à-dire qu’elles sont des roches magmatiques d’origine mantélique et qui se sont formées en contexte de subduction. Ces granitoïdes étaient, du point de vue minéralogique, riches en feldspaths (± 55% de la roche totale) où domine l’albite. Ces formations appartiennent à la classe des granitoïdes kibariens du groupe de Bitale.
Author Keywords: Pétrologie, Gneiss, Pegmatite, Composition minéralogique, Bunyakiri.
How to Cite this Article
I. Chunga Chako, “Etude pétrologique des gneiss de Bunyakiri au Sud Kivu, République Démocratique du Congo,” International Journal of Innovation and Applied Studies, vol. 19, no. 2, pp. 376–384, February 2017.
