Application of Remote Sensing for the Mapping of Geological Structures in Rainforest Area: A Case Study at the Matomb-Makak Area, Center-South Cameroon

Metang Victor^1, , Nkoumbou Charles¹, Tchakounté Numbem Jacqueline¹ and Njopwouo Daniel²

¹University of Yaoundé 1, Faculty of Science, Department of Earth Sciences. P.O. Box 812 Yaoundé-Cameroon

²University of Yaoundé 1, Faculty of Science, Department of Inorganic Chemistry. P.O. Box 812 Yaoundé-Cameroon

Cite this paper

Metang Victor, Nkoumbou Charles, Tchakounté Numbem Jacqueline and Njopwouo Daniel. Application of Remote Sensing for the Mapping of Geological Structures in Rainforest Area: A Case Study at the Matomb-Makak Area, Center-South Cameroon. Journal of Geosciences and Geomatics. 2014; 2(5):196-207. doi: 10.12691/JGG-2-5-3

Abstract

In the areas with rainforest vegetation, the use of SRTM (Shuttle Radar topography Mission) data because of their penetrative characters, high quality and availability, offers a new approach for the detection and interpretation of the geological structures. This paper presents the new structural mapping results of the Matomb-Makak area (western part of the Pan-African Yaoundé series), based on the combined field survey and satellite image processing methods. The study area is characterized by dense forest vegetation with difficult access, scarcity and discontinuity of the available outcrops. As a consequence, geological mapping in this type of environment is difficult, time-consuming, expensive, and even dangerous and not accurate. During the field work, 280 outcrops have been investigated in which five main lithological units have been distinguished. In order to identify the foliation trajectories and the fractures network of kilometric scale, the techniques of remote sensing were used. The processing of SRTM data led to the detection of linear anomalies. These anomalies have been verified and validated to structural map on the basis of field data. The analysis of the structural map indicates: (1) two directions of S₂ foliation (NE-SW major direction, locally folded and NW-SE secondary direction), (2) one family of faults trending NW-SE which locally displace the foliation, (3) a ductile shear zone with NNE-SSW trends which deflects the S₂ foliation. The two directions of foliation observed in the Matomb-Makak area as well as the NW-SE direction of fault are similar to those observed in the Yaoundé series by other authors. However, the structural map obtained from the interpretation of field data is quite different to that obtained from remote sensing. We have noticed that the folding structures resulting from the interpretation of the field data are not observed on the structural map obtained from the interpretation of satellite image processing. Thus, the mapping of foliation trajectories in the rainforest area on the solely basis of the field measurements, is most of the time, an extrapolation which does not represent the structural architecture at regional scale. It is concluded that the combination of field-based mapping and remote sensing methods are useful tool for the mapping of geological structures within the densely vegetated regions of southern Cameroun.

Keywords

remote sensing, geological structures, foliation trajectories, rain forest area, cameroon

Copyright

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References

[1]	Nzenti J.P., Barbey, P., Bertrand, JML., Macaudiere, J. (1994). La chaîne panafricaine au Cameroun: cherchons suture et modèle. In : S.G.F. édit., 15e réunion des Sciences de la Terre, Nancy, France, 99p.
[2]	Toteu, S.F., Penaye, J., Poudjom Djomani, Y.H.. Geodynamic evolution of the Pan-African belt in Central Africa with special reference to Cameroon. Canadian Journal of Earth Sciences, 41, 73-85, 2004.
[3]	Vicat, J.P., Pouclet, A., Nkoumbou, C. and Semé Mouangué, A. Le volcanisme fissural néoprotérozoïque des séries du Dja inférieur, de Yokadouma (Cameroun) et de Nola (RCA)-Signification géotectonique. Comptes Rendus de l’Académie des Sciences de Paris, 325, 671-677, 1997.
[4]	Nédélec, A., Macaudière, J., Nzenti, J.P., Barbey, P. Evolution structurale et métamorphique des schistes de Mbalmayo (Cameroun): implications pour la structure de la zone mobile panafricaine d’Afrique centrale au contact du craton du Congo. Comptes Rendus de l’Académie des Science Paris, 303 (Série II1), 75-80, 1986.
[5]	Nzenti, J.P., Barbey, P., Macaudiere, J., Soba, D. Origin and evolution of the late Precambrian high-grade Yaounde gneisses (Cameroon). Precambrian Research, 38, 91-109, 1988.
[6]	Barbey, P., Macaudiere, J. and Nzenti, J.P. High pressure dehydration melting of metapelites: evidence from the migmatites of Yaounde (Cameroon). Journal of Petrology, 31 (2), 401-427, 1990.
[7]	Stendal, H., Toteu, S.F., Frei, R., Penaye, J., Njel, U.O., Bassahak, J., Nni, J., Kankeu, B., Ngako, V., Hell, J.V. Derivation of detrital rutile in the Yaounde region from the Neoproterozoic Pan-African belt in southern Cameroon (Central Africa). Journal of African Earth Sciences, 44, 443-458, 2006.
[8]	Yonta-Ngouné, C., Nkoumbou, C., Barbey, P., Le Breton, N., Montel, J.M., Villieras, F. Geological context of the Boumnyebel talcschists (Cameroun): Inferences on the Pan-African Belt of Central Africa. Comptes Rendus Geosciences, 342, 108-115, 2010.
[9]	Randranasalo, E.B. Nouvelles méthodes de cartographie sur le socle protérozoïque du sud de Madagascar: Nature et géométrie de la croûte continentale d’un domaine orogénique en convergence, implications économiques. Thèse de doctorat, Université Terre Solide, 307 p., 2009.
[10]	Amer, R., Kusky, T., Ghulam, A. Lithological mapping in the Central Eastern Desert of Egypt using ASTER data. Journal of African Earth Sciences, 56, 75-82, 2010.
[11]	Moussa Isseini. Croissance et différenciation crustales au Néoprotérozoïque. Exemple du domaine panafricain du Mayo Kebbi au Sud-Ouest du Tchad. Thèse de doctorat, Université de Nancy, 339 p., 2011.
[12]	Ouattara G., Koffi, G.B., and Yao, K. A. Contribution des images satellitales Landsat 7 ETM+ à la cartographie lithostructurale du Centre-Est de la Côte d’Ivoire (Afrique de l’Ouest). International Journal of Innovation and Applied Studies, 1(1) 61-75, 2012.
[13]	Owona, S., Mvondo Ondoa, J., Ratschbacher, L., Ndzana, M.P.S., Tchoua, F.M., Ekodeck, G.E. La géométrie de la tectonique archéenne, Paléo et néoprotérozoïque dans le Sud-Ouest du Cameroun. Comptes Rendus Geosciences, 343, 312-322, 2011.
[14]	Nzenti, J.P., Njanko, T., Njiosseu, E.L.T. et Tchoua, F.M. Les domaines granulitiques de la chaîne panafricaine Nord-Equatoriale au Cameroun. In Géologie et environnement au Cameroun, Vicat et Bilong editors, Collection Geocam I/1998. Université de Yaoundé I, 255-264, 1998.
[15]	Mvondo, H., Owona, S., Mvondo Ondoa, J., Essono, J. Tectonic evolution of the Yaounde segment of the Neoproterozoic Central Africa Orogenic Belt in southern Cameroon. Canadian Journal of African Earth Sciences, 44, 433-444, 2007.
[16]	Nzenti, J.P., Barbey, P., Jegouzo, P., et Moreau, C. Un nouvel exemple de ceinture granulitique dans une chaîne protérozoïque de collision: les migmatites de Yaoundé au Cameroun. Comptes Rendus de l’Académie des Sciences de Paris, 299, 1197-1199, 1984.
[17]	Penaye, J., Toteu, S.F., Michard, A., Van Schmus, W.R., Nzenti J.P. U-Pb and Sm-Nd preliminary geochronologic data on the Yaoundé series, Cameroon: reinterpretation of granulitic rock as the suture of the collision in the « Centrafricain » belt. Comptes Rendus de l’Académie des Sciences de Paris, 317, 789-794, 1993.
[18]	Ngnotué, T., Ganno, S., Nzenti, J.P., Schulz, B., Tchaptchet Tchato, D. and Suh Cheo, E. Geochemistry and geochronology of Peraluminous High-K granitic leucosomes of Yaoundé series (Cameroon): evidence for a unique Pan-African magmatism and melting event in North Equatorial Fold Belt. International Journal of Geosciences, 3, 525-548, 2012.
[19]	Toteu, S.F., Van Schmus, W.R., Penaye, J., Nyobe, J.B. U-Pb and Sm-Nd evidence for Eburnean and Pan-African high grade metamorphism in cratonic rocks of Southern Cameroon. Precambrian Research, 67, 321-347, 1994.
[20]	Toteu, S.F., Van Schmus, W.R., Penaye, J., Michard, A. New U-Pb and Sm-Nd data from north-central Cameroon and its bearing on the pre-Pan-African history of central Africa. Precambrian Research, 108, 45-73, 2001.
[21]	Toteu, S.F., Penaye, J., Deloule, E., Van Schmus, W.R. and Tchameni, R.. Diachronous evolution of volcano-sedimentary basins north of the Congo Craton: insights from U/Pb ion microprobe dating of zircons from the Poli, Lom and Yaoundé Groups (Cameroon). Journal of African Earth Sciences 44, 428-442, 2006.
[22]	Hobbs, B.E., Means, B.W.D., Williams, P.F., 1976. An outline of structural geology. New York, J Wileys and Sons, 379 p.
[23]	Mvondo, H., Den Brok, S. W.J. and Mvondo Ondoa, J. Evidence for extension and exhumation of the Yaounde nappe (Pan-African fold belt, Cameroon). Journal of African Earth Sciences 36, 215-231, 2003.
[24]	Piyaphong, C. DEM application for geological structure interpretation: A case study at the Koh Samui Area, gulf of Thailand. World Applied Sciences Journal, 17 (11), 1516-1520, 2012.
[25]	Schetselaar, E.M., Tiainen, M. and Woldai, T. Integrated geological interpretation of remotely sensed data to support geological mapping in Mozambique. Geological Survey of Finland, Special Paper, 48, 35-63, 2008.