This study is based on the analysis and interpretation of aeromagnetic data using version 8.4 of the GeosoftOasis MontajSoftware, to map the subsurface or deep geological structures that affected the geological formations of the Ngaounderearea. The use of the standard aeromagnetic methods made it possible to draw up the maps of the residual magnetic field reduced to the equator (RTE), the horizontal gradient (HG), the analytical signal (AS) and that of the Euler solutions (ED) to find the main magnetic facies corresponding to these structures. The geological formations of the studied area thus appear
to be intensely fractured by a NE-SW (N45°E) and ENE-WSW (N70°E) main orientation fault system, the depth of which has been estimated by combining the three-analytical methods HG, AS and ED. Advanced magmatic map analysis revealed dikes associated with vertical faults in the studied area. The development of an interpretative geological map taking into account the basic geology, the deep faults, the identified dikes and the mineralization index made it possible to extract a correlation between geological structures and mineralization of the studied area. The 2.5D modelling of two magnetic profiles plotted on the reduced residual map at the equator was performed to approximate the geometry
and depth of the dikessector, which are potential sources of mineralization here.
References
[1]
Belinga, E. (1972) The Alteration of Basaltic Rocks and the Process of Bauxitization in Adamawa (Cameroon). Thesis Doc., State University, Paris, 571.
[2]
Dumont, J.F. (1987) Structural Study of the North and South Borders of the Adamawa Plateau: Influence of the Atlantic Context. Geodynamics, 1, 9-13.
[3]
Ngounouno, I. (1998) Petrology and Geodynamic Framework of the Cenozoic Magmatism of the Cameroon Line. In: Vicat, J.P. and Bilong, P., Eds., Geoscience in Cameroon, Collection GEOCAM, Vol. 1, 169-184.
[4]
Poudjom-Djomani, Y.H., Diament, M. and Albouy, Y. (1992) Mechanical Behaviour of the Lithosphere beneath the Adamawa Uplift (Cameroon, West Africa) Based on Gravity Data. Journal of Africa Earth Sciences, 15, 81-90.
https://doi.org/10.1016/0899-5362(92)90009-2
[5]
Poudjom-Djomani, Y.H. (1993) Contribution of Gravimetry to the Study of the Continental Lithosphere and Geodynamic Implications. Study of an Intraplaque Bombing: The Adamaoua Massif (Cameroon). PhD Thesis, University South of Paris, Paris, 229.
[6]
Poudjom-Djomani, Y.H., Nnange, J.M., Diament, M., Ebinger, C.J. and Fairhead, J.D. (1995) Effective Elastic Thickness and Crustal Thickness Variations in West Central Africa Inferred from Gravity Data. Journal of Geophysical Research, 100, 47-70.
[7]
Poudjom-Djomani, Y.H., Diament, M. and Wilson, M. (1997) Lithospheric Structures across the Adamawa Plateau (Cameroon) from Gravity Studies. Tectonophysics, 273, 317-327. https://doi.org/10.1016/S0040-1951(96)00280-6
[8]
Noutchogwe, T.C., Tabod, C.T. and Manguelle-Dicoum, E. (2006) A Gravity Study of the Crust Beneath the Adamawa Fault Zone, West Central Africa. Journal of geophysics and Engineering, 3, 82-89. https://doi.org/10.1088/1742-2132/3/1/009
[9]
Noutchogwe, T.C. (2010) Geophysical Investigation in the Adamawa Region by Gravimetric and Magnetic Methods: Structural and Hydrogeological Implications. PhD Thesis, University of Yaoundé I, Yaoundé, 146.
[10]
Marechal, A. and Vincent, P.R. (1971) The Cretaceous Pit of South Adamawa (Cameroon). ORSTOM Book, Geological Series, 3, 67-83.
[11]
Temdjim, R. (1986) Volcanism of the Region of Ngaoundere (Adamawa-Cameroon). Volcanic and Petrographic Study. Thesis, 3rd Cycle, University Clermont Ferrand, France, 185.
[12]
Temdjim, R. (2006) Contribution to the Knowledge of the Upper Mantle of Cameroon through the Study of Ultrabasic and Basic Enclaves Ascended by the Volcanoes of Youkou (Adamawa) and Nyos (Cameroon Line). Thesis State, University of Yaounde I, 346.
[13]
Ngounouno, I., Moreau, C., Deruelle, B., Demaiffe, D. and Montigny, R. (2001) Petrology of the Subsaturated Alkaline Complex of Koukoumi (North of Cameroon). Bulletin de la Société Géologique de France, 172, 675-686.
https://doi.org/10.2113/172.6.675
[14]
Lassere, M. (1961) Geological Map of Recognition at a Scale of 1: 500,000, Cameroon Territory, Ngaoundere East. Dir. Mines Geol. Cameroon.
[15]
Koch, P. (1953) Geological Map of Cameroon. Banyo Clipping, with Explanatory Note.
[16]
Cornacchia, M. and Dars, R. (1983) A Major Structural Feature of the African Continent: The Central African Lineaments from Cameroon to the Gulf of Aden. Bull. COC.Geol. France, 25, 101-109.
[17]
Lasserre, M. (1961) Geological Map of Reconnaissance at Scale 1/500000, Territory of Cameroon, Ngaoundere-East. Dir, Mines Geol Cameroon, Yaounde, Camerooùn.
[18]
EnoBelinga (1984) Geology of Cameroon. Yaounde University, Yaounde, 308.
[19]
Toteu, S.F., Van Schmus, W.R., Penaye, J. and Michard, A. (2001) 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.
https://doi.org/10.1016/S0301-9268(00)00149-2
[20]
Tchameni, R., Pouclet, A., Penaye, J., Ganwa, A.A. and Toteu, S.F. (2006) Petrography and Geochemistry of the Ngaoundere Pan-African Granitoids in Central Cameroon: Implications for Their Sources and Geological Setting. Journal of African Earth Sciences, 44, 511-529. https://doi.org/10.1016/j.jafrearsci.2005.11.017
[21]
Paterson, Grant and Watson Ltd. (1976) Interpretation of an Aeromagnetic Survey Overpart of the United Republic of Cameroon. ACDI, Toronto, 190.
[22]
Phillips, J.D. (1998) Processing and Interpretation of Aeromagnetic Data for the Santa Cruz Basin—Patahonia Mountains Area, South-Central Arizona. U.S. Geological Survey Open-File Report, Arizona, 2-98.
[23]
Ngoh, J.D., Ndougsa-Mbarga, T., Assembe, S.P., Meying, A., Owono, O.U. and Tabod, T.C. (2017) Evidence of Structural Facts Inferred from Aeromagnetic Data Analysis over the Guider-Maroua Area (Northern Cameroon). International Journal of Geosciences, 8, 781-800. https://doi.org/10.4236/ijg.2017.86044
[24]
Cordell, L. and Grauch, V.J.S. (1982) Mapping Basement Magnetization Zones from Aeromagnetic Data in the San Juan Basin, New Mexico. SEG Technical Program Expanded Abstracts, 246-247.
[25]
Cordell, L. and Grauch, V.J.S. (1985) Mapping Basement Magnetization Zones from Aeromagnetic Data in the San Juan Basin, New Mexico. In: Hinze, W.J., Ed., The Utility of Regional Gravity and Magnetic Anomaly Maps, Society of Exploration Geophysicists, 181-197. https://doi.org/10.1190/1.0931830346.ch16
[26]
Nabighian, M.N. (1972) The Analytic Signal of Two-Dimensional Magnetic Bodies with Polygonal Cross-Section: Its Properties and Use for Automated Anomaly Interpretation. Geophysics, 37, 507-517. https://doi.org/10.1190/1.1440276
[27]
Roest, W.R., Verhoef, J. and Pilkigton, M. (1992) Magnetic Interpretation Using the 3-D Signal Analytic. Geophysics, 57, 116-125. https://doi.org/10.1190/1.1443174
[28]
Macleod, I.N., Jones, K. and Dai, T.F. (1993) 3-D Analytic Signal in the Interpretation of Total Magnetic Field Data at Low Magnetic Latitudes. Exploration Geophysics, 24, 679-688. https://doi.org/10.1071/EG993679
[29]
Jeng, Y., Lee, Y.L., Chen, C.Y. and Lin, M.J. (2003) Integrated Signal Enhancements in Magnetic Investigation in Archaeology. Journal of Applied Geophysics, 53, 31-48. https://doi.org/10.1016/S0926-9851(03)00015-6
[30]
Thompson, D.T. (1982) A New Technique for Making Computer-Assisted Depth Estimates from Magnetic Data. Geophysics, 47, 31-37.
https://doi.org/10.1190/1.1441278
[31]
Reid, A.B., Allsop, J.M., Granser, H., Millett, A.J. and Somerton, I.W. (1990) Magnetic Interpretation in Three Dimensions Using Euler Deconvolution. Geophysics, 55, 80-90. https://doi.org/10.1190/1.1442774
[32]
Talwani, M. and Heirzler, J.R. (1964) Computation of Magnetic Anomalies Caused by Two-Dimensional Bodies with Application to the Mineral Industry Shape. Computers in the Mineral Industry, School of Earth Sciences, Stanford University, Stanford, 464-480.
[33]
Grant, F.S. and West, G.F. (1965) Interpretation Theory in Applied Geophysics. McGraw-Hill, New York, 584.
[34]
Zeng, H. (1989) Estimation of the Degree of Polynomial Fitted to Gravity Anomalies and Its Application. Geophysical Prospecting, 37, 959-973.
https://doi.org/10.1111/j.1365-2478.1989.tb02242.x
[35]
Khattach, D., Keating, P., Mili, E.M., Chennouf, T., Andrieux, P. and Milhi, A. (2004) Contribution of Gravimetry to the Study of Basffa Structure (North-East Morocco): Hydrogeological Implications. Géoscience, 336, 1427-1432.
https://doi.org/10.1016/j.crte.2004.09.012
[36]
Khattach, D., Mraoui, H., Sbibih, D. and Chennouf, T. (2006) Multi-Scale Wavelet Analysis of Geological Contacts: Application to the Gravimetry of Nord-Eastern Morocco. Comptes Rendus Geoscience, 338, 521-526.
https://doi.org/10.1016/j.crte.2006.03.002
[37]
Blakely, R.J. and Simpson, R.W. (1986) Approximating Edges of Source Bodies from Magnetic or Gravity Anomalies. Geophysics, 51, 1494-1498.
https://doi.org/10.1190/1.1442197
[38]
Hunt, C.P., Moskowitz, B.M. and Banerjee, S.K. (1995) Magnetic Properties of Rocks and Minerals. In: Ahrens, T.J., Ed., Rock Physics & Phase Relations: A Handbook of Physical Constants, Vol. 3, American Geophysical Union, Washington DC, 189-204. https://doi.org/10.1029/RF003p0189
