[ Etude des paragenèses minérales des roches vertes de la vallée de M’vunzi du Territoire de Seke-Banza (Province du Kongo Central, RD Congo) ]
Volume 65, Issue 1, February 2023, Pages 48–60
Patrick Mukonkole Mukonkole1, Daddy Patrick Ilito Lofongo2, Henock Tshombe Mbaya3, Nebys Mupepe Ngayipa4, Joël-André Opey Ambur5, Olga Mukaka Kimwesa6, and Anne-Marie Tshibwabwa Tshiswaka7
1 Centre de Recherches Géologiques et Minières (CRGM), B.P.: 898, Kinshasa I, RD Congo
2 Centre de Recherches Géologiques et Minières (CRGM), B.P.: 898, Kinshasa I, RD Congo
3 Centre de Recherches Géologiques et Minières (CRGM), B.P.: 898, Kinshasa I, RD Congo
4 Centre de Recherches Géologiques et Minières (CRGM), B.P.: 898, Kinshasa I, RD Congo
5 Centre de Recherches Géologiques et Minières (CRGM), B.P.: 898, Kinshasa I, RD Congo
6 Centre de Recherches Géologiques et Minières (CRGM), B.P.: 898, Kinshasa I, RD Congo
7 Centre de Recherches Géologiques et Minières (CRGM), B.P.: 898, Kinshasa I, RD Congo
Original language: French
Copyright © 2023 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 traveling prospecting along the M’vunzi River has collected samples of the greenstone which have been the subject of macroscopic and microscopic observations of the thin sections made in the petrography laboratory. The present study has enabled us to identify in addition to the three types of rocks previously described by our predecessors, a fourth petrographic type which is a chloritoschist. In addition, two new minerals have been identified including «garnet» and «cordierite», respectively in an amphibolite and in a chloritoschist. The mineralogical paragenesis of the different petrographic types described to date in the M’vunzi valley composed of: epidote-chlorite-quartz, epidote-plagioclase-albite-chlorite-calcite, chlorite-biotite-quartz and chlorite-biotite-albite-quartz are typically secondary mineral paragenesis and indicate that all basic lavas in the study area were affected by regional greenschist facies metamorphism which is clearly justified by the appearance of chlorite in each mineralogical paragenesis. These results allowed us to deduce that the M’vunzi valley is lined with Gangila green rocks, the main ones being amphibolites, chloritoschists, micaschists and epidotites. It is therefore, for the most part, ancient basaltic lavas very rich in plagioclase which subsequently transformed into green rocks. The latter are the products due to the regional metamorphic gradient of Low Pressure and High Temperature (LP-HT).
Author Keywords: Gondwana, Rodinia, Panafrican, metabasalt, amphibolite, epidotite.
Volume 65, Issue 1, February 2023, Pages 48–60
Patrick Mukonkole Mukonkole1, Daddy Patrick Ilito Lofongo2, Henock Tshombe Mbaya3, Nebys Mupepe Ngayipa4, Joël-André Opey Ambur5, Olga Mukaka Kimwesa6, and Anne-Marie Tshibwabwa Tshiswaka7
1 Centre de Recherches Géologiques et Minières (CRGM), B.P.: 898, Kinshasa I, RD Congo
2 Centre de Recherches Géologiques et Minières (CRGM), B.P.: 898, Kinshasa I, RD Congo
3 Centre de Recherches Géologiques et Minières (CRGM), B.P.: 898, Kinshasa I, RD Congo
4 Centre de Recherches Géologiques et Minières (CRGM), B.P.: 898, Kinshasa I, RD Congo
5 Centre de Recherches Géologiques et Minières (CRGM), B.P.: 898, Kinshasa I, RD Congo
6 Centre de Recherches Géologiques et Minières (CRGM), B.P.: 898, Kinshasa I, RD Congo
7 Centre de Recherches Géologiques et Minières (CRGM), B.P.: 898, Kinshasa I, RD Congo
Original language: French
Copyright © 2023 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 traveling prospecting along the M’vunzi River has collected samples of the greenstone which have been the subject of macroscopic and microscopic observations of the thin sections made in the petrography laboratory. The present study has enabled us to identify in addition to the three types of rocks previously described by our predecessors, a fourth petrographic type which is a chloritoschist. In addition, two new minerals have been identified including «garnet» and «cordierite», respectively in an amphibolite and in a chloritoschist. The mineralogical paragenesis of the different petrographic types described to date in the M’vunzi valley composed of: epidote-chlorite-quartz, epidote-plagioclase-albite-chlorite-calcite, chlorite-biotite-quartz and chlorite-biotite-albite-quartz are typically secondary mineral paragenesis and indicate that all basic lavas in the study area were affected by regional greenschist facies metamorphism which is clearly justified by the appearance of chlorite in each mineralogical paragenesis. These results allowed us to deduce that the M’vunzi valley is lined with Gangila green rocks, the main ones being amphibolites, chloritoschists, micaschists and epidotites. It is therefore, for the most part, ancient basaltic lavas very rich in plagioclase which subsequently transformed into green rocks. The latter are the products due to the regional metamorphic gradient of Low Pressure and High Temperature (LP-HT).
Author Keywords: Gondwana, Rodinia, Panafrican, metabasalt, amphibolite, epidotite.
Abstract: (french)
La prospection itinérante le long de la rivière M’vunzi ont permis de collecter des échantillons des roches vertes qui ont fait l’objet des observations macroscopiques et microscopiques des lames minces confectionner au laboratoire de pétrographie. La présente étude nous a permis d’identifier outre les trois types des roches précédemment décrites par nos prédécesseurs, un quatrième type pétrographique qui est un « chloritoschiste ». En plus, deux nouveaux minéraux ont été identifiés dont le « grenat » et la « cordiérite«, respectivement dans une amphibolite et dans un chloritoschiste. Les paragenèses minéralogiques des différents types pétrographiques décrits à ce jour dans la vallée de M’vunzi composées de: épidote-chlorite-quartz, épidote-plagioclase-albite-chlorite-calcite, chlorite-biotite-quartz et chlorite-biotite-albite-quartz sont typiquement des paragenèses de minéraux secondaires et indiquent que toutes les laves basiques du secteur d’étude ont été affectées par le métamorphisme régional de greenschist faciès qui se justifie clairement par l’apparition de la chlorite dans chaque paragenèse minéralogique. Ces résultats ont permis de déduire que la vallée de la M’vunzi est tapissée des roches vertes de Gangila dont les principales sont les amphibolites, les chloritoschistes, les micaschistes et les épidotites. Ce sont donc, pour la plupart d’anciennes laves basaltiques très riches en plagioclase qui se sont transformées par la suite du métamorphisme en roches vertes. Ces dernières sont les produits dus au gradient métamorphique régional de Basse Pression et Haute Température (BP-HT).
Author Keywords: Gondwana, Rodinia, Panafricain, métabasalte, amphibolite, épidotite. En anglais : Gondwana, Rodinia, Panafrican, metabasalt, amphibolite, epidotite.
How to Cite this Article
Patrick Mukonkole Mukonkole, Daddy Patrick Ilito Lofongo, Henock Tshombe Mbaya, Nebys Mupepe Ngayipa, Joël-André Opey Ambur, Olga Mukaka Kimwesa, and Anne-Marie Tshibwabwa Tshiswaka, “Study of the mineral parageneses of the green rocks of the M’vunzi valley of the Territory of Seke-Banza (Kongo Central Province, DR Congo),” International Journal of Innovation and Scientific Research, vol. 65, no. 1, pp. 48–60, February 2023.
