[ Pétrologie des corps sédimentaires crétacés du Moungo-Fleuve (Sous-Bassin Sédimentaire de Douala, Cameroun) ]
Volume 26, Issue 4, July 2019, Pages 1066–1077
Christel Sobdjou KEMTEU1, Abakar MAHAMAT2, François Bidzang NDONG3, Mero Yannah4, Gabriel NGUEUTCHOUA5, and Simon NGOS III6
1 Institut de Recherches Géologiques et Minières, BP : 4110 Nlongkak, Yaoundé, Cameroon
2 Centre de Recherches Géologiques et Minières, BP : 333, Garoua, Cameroon
3 Institut de Recherches Géologiques et Minières, BP : 4110 Nlongkak, Yaoundé, Cameroon
4 Institut de Recherches Géologiques et Minières, BP : 4110 Nlongkak, Yaoundé, Cameroon
5 Département des Sciences de la Terre et de l’Univers, Université de Yaoundé 1, BP : 812 Yaoundé, Cameroon
6 Département des Sciences de la Terre et de l’Univers, Université de Yaoundé 1, BP : 812 Yaoundé, Cameroon
Original language: French
Copyright © 2019 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.
Many research studies have been done in the Mungo-River valley, they were mostly concerning the genesis and stratification of outcrops, but not really their petrology (description and classification). According to those reasons, this article is going to increase the petrology’s understanding of Mungo-River’s cretaceous outcrops, in Douala sub-basin. So, the studies have been done on Moundeck village’s outcrops and near the railway bridge on the Mungo-River. In fact, the studies were concerning the description of eight outcrops; the classification of their facies and the interpretation of their genesis. The description of outcrops has showed that they are constituted of positive and negative sequences. The thin sections have permitted to classify the facies described as litharenites and lithic arkoses, which are friable rocks. The genesis of Mungo-River’s outcrops could be understood according to two approaches. On the one hand, the sedimentary structures such as intercrossed and oblique stratifications observed on outcrops signify that, the sedimentation had been taken place in a fluvio-deltaic environment. On the other hand, the positive and negative sequences delimited on described outcrops, testify the influence of sedimentary cycles (transgression and regression) within the depositing environment.
Author Keywords: Cretaceous, rhythmic sedimentation, fluvio-deltaic depositing, sedimentary cycles.
Volume 26, Issue 4, July 2019, Pages 1066–1077
Christel Sobdjou KEMTEU1, Abakar MAHAMAT2, François Bidzang NDONG3, Mero Yannah4, Gabriel NGUEUTCHOUA5, and Simon NGOS III6
1 Institut de Recherches Géologiques et Minières, BP : 4110 Nlongkak, Yaoundé, Cameroon
2 Centre de Recherches Géologiques et Minières, BP : 333, Garoua, Cameroon
3 Institut de Recherches Géologiques et Minières, BP : 4110 Nlongkak, Yaoundé, Cameroon
4 Institut de Recherches Géologiques et Minières, BP : 4110 Nlongkak, Yaoundé, Cameroon
5 Département des Sciences de la Terre et de l’Univers, Université de Yaoundé 1, BP : 812 Yaoundé, Cameroon
6 Département des Sciences de la Terre et de l’Univers, Université de Yaoundé 1, BP : 812 Yaoundé, Cameroon
Original language: French
Copyright © 2019 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
Many research studies have been done in the Mungo-River valley, they were mostly concerning the genesis and stratification of outcrops, but not really their petrology (description and classification). According to those reasons, this article is going to increase the petrology’s understanding of Mungo-River’s cretaceous outcrops, in Douala sub-basin. So, the studies have been done on Moundeck village’s outcrops and near the railway bridge on the Mungo-River. In fact, the studies were concerning the description of eight outcrops; the classification of their facies and the interpretation of their genesis. The description of outcrops has showed that they are constituted of positive and negative sequences. The thin sections have permitted to classify the facies described as litharenites and lithic arkoses, which are friable rocks. The genesis of Mungo-River’s outcrops could be understood according to two approaches. On the one hand, the sedimentary structures such as intercrossed and oblique stratifications observed on outcrops signify that, the sedimentation had been taken place in a fluvio-deltaic environment. On the other hand, the positive and negative sequences delimited on described outcrops, testify the influence of sedimentary cycles (transgression and regression) within the depositing environment.
Author Keywords: Cretaceous, rhythmic sedimentation, fluvio-deltaic depositing, sedimentary cycles.
Abstract: (french)
La plupart des travaux antérieurs menés dans la vallée du fleuve moungo a surtout porté sur la genèse et la stratification des corps sédimentaires et très peu sur leur pétrologie (description et classification). C’est dans cet ordre d’idée que cet article contribue à améliorer la compréhension de la pétrologie des corps sédimentaires crétacés du Moungo-Fleuve, dans le sous-bassin sédimentaire de Douala. Pour se faire, les études ont été menées sur les affleurements situés dans le village Moundeck et au niveau du pont ferroviaire sur le fleuve moungo. Il s’est agi de décrire huit affleurements ; de proposer une classification des facies les constituant ; et d’interpréter la genèse de ces corps sédimentaires. La description des affleurements a montré que ces derniers sont essentiellement constitués de séquences positives et négatives qui sont caractérisées respectivement par un granoclassement décroissant et croissant. La pétrographie microscopique a permis de classer les roches formant les faciès décrits, comme étant des litharenites et des arkoses lithiques qui sont peu consolidées. La genèse des corps sédimentaires du Moungo-Fleuve peut être interprétée à partir de la combinaison de deux approches. D’une part, les structures sédimentaires telles que les stratifications obliques et entrecroisées observées sur les affleurements décrits, laissent penser à un environnement de dépôt fluvio-deltaique. D’autre part, la succession de séquences positives et négatives délimitées sur les affleurements décrits, témoignent de l’influence des cycles sédimentaires (transgressions et régressions) dans le milieu de dépôt.
Author Keywords: Crétacé, sédimentation rythmique, dépôt fluvio-deltaique, Cycles sédimentaires.
How to Cite this Article
Christel Sobdjou KEMTEU, Abakar MAHAMAT, François Bidzang NDONG, Mero Yannah, Gabriel NGUEUTCHOUA, and Simon NGOS III, “Petrology of Mungo-River cretaceous sedimentary outcrops (Douala Sedimentary Sub-Basin, Cameroon),” International Journal of Innovation and Applied Studies, vol. 26, no. 4, pp. 1066–1077, July 2019.
