b'The origin of the Bangui magnetic anomalyFeatureof EMAG2-v3 magnetic data were considered. PreliminaryBenkova N. P., Dolginow S. S., Simonenko T. N., 1973. Residual magnetic results from qualitative processing (a stabilisedmagnetic field from the satellite Cosmos 49. Journal of reduction to the pole, upward continuation, horizontal gradient,Geophysical Research, 78, 798-803.vertical gradient, analytical signal, pseudo-gravimetry) showBhattacharryya B., Lei-Kuang Leu, 1975. Spectral analysis of that (1) there are many sources for the BMA; (2) the sources ofgravity and magnetic anomalies due to two-dimensional the BMA are closely linked with the Congo craton structures; (3)structures. Geophysics, 40, 993-1013.the BMA has a geological origin; (4) there is no link between theBoukeke D., 1994. Structures crustales dAfrique Centrale BMA and the surface rocks; (5) the petrography could vary fromdduites des anomalies gravimtrique et magntique : le Banded Iron Formations to mafic granulites; (6) the BMA is adomaine Prcambrien de la Rpublique Centrafricaine et du long wavelength anomaly associated with secondary anomaliesSud-Cameroun. Thse de Doctorat PhD, Universit de Paris preferentially oriented E-W; (7) the geodynamic processes ofSud, Centre Orsay, ORSTOM, 278p.emplacement of sources of the BMA are related to the regionalClark, D.A., 1999. Magnetic petrology of igneous intrusions: E-W and ENE-WSW tectonics that affected the Precambrian toimplications for exploration and magnetic interpretation. Pan-African basement. The quantitative analysis was initiated byExplor. Geophys. 30, 526.a geothermal approach. The Curie depths along the BMA, theCollignon, F., 1968. Gravimtrie de reconnaissance du estimation of geothermal gradients and heat fluxes were thusCameroun. ORSTOM, Paris, p. 37.highlighted (Figure 6). Three potential sources of the anomalyDorbath C., Dorbath L., Floch H., Mauplot J. P., Rouyre P., 1981. along the major ENE-WSW direction were imaged, all locatedCampagne denregistrement sismologique sur lanomalie in the Congo Craton, at a maximum depth of 38 km2 km.magntique de Bangui. ORSTOM, 11p.The 2.5D and 2.3/4D models thus revealed on nine N-S profilesDorbath C., Dorbath L., Roland Gaulon, R., Hatzfeld, D., 1985. selected at constant distance: (1) a magnetic crust indicativeSeismological investigation of the Bangui magnetic anomaly of a possible circulation of magnetic fluid; (2) mafic granuliteregion and its relation to the margin of the Congo craton. intrusions, (3) BIF (Banded Iron Formation) intrusions. Earth and Planetary Science Letters, 75 (23), 231-244. https://doi.org/10.1016/0012-821X(85)90105-0.Dostal J. Dupuy C. Poidevin J., 1985 Geochemistry of Future issues Precambrian basaltic rocks from the Central African Republic A direct economic outcome will be necessary to promote(Equatorial Africa). Can. J. Earth Sci. 22, 653-662.ongoing geophysical research in Central Africa; hence theDumont J. F., 1986. Identification par tldtection de laccident ongoing search for links between the Bangui magnetic anomalyde la Sanaga (Cameroun). Sa position dans le contexte des and mineralisation of importance in the sub-region. Thegrands accidents dAfrique Centrale et de la limite du craton acquisition of seismic and electromagnetic data, in additioncongolais. Geodynamique, 1, 13-19.to the magnetic and gravimetric data already acquired, wouldEbinger C. J., Keir D., Bastow D. I., K.Whaler, J. O. S. Hammond, significantly help to quantify various parameters of relevance toAyele A., Miller M., Tiberi C., Hautot S., 2017. Crustal structure the exploitation of mineral resources both in the Central Africanof active deformation zones in Africa: Implication for Global Republic and in Cameroon. Crustal Processes. Tectonics, 36, 3298-3332. https://doi.org/10.1002/2017TC004526Feybesse J. L., Johan V., Triboulet C., Guerrot C., Mayaga-Mikolo Acknowledgements F., Bouchot V., Eko Ndong J., 1998. The West Central African belt: a model of 2.5-2.0 Ga accretion and two-phase orogenic This work was carried out at the Geosciences Natural Resourcesevolution. Precambrian Research, 87, 161-216.and Environment Laboratory in the University of Douala inGallacher, R.J., Bastow, I.D., 2012. The development Cameroon. It was supervised by Pr Etame Jacques and Bassekaof the Cameroon Volcanic Line: evidence from Charles. And deeply directed by Dr Yvette Poudjom Djomaniteleseismic receiver functions. Tectonics, 31. https://doi.from Geoscience Australia. The participation of differentorg/10.1029/2011TC003028.teams from the Geosciences Environnement ToulouseGidler R. W. Taylor P. T. Frawler J. J., 1992. A possible impact (GET) laboratory in France through Dr Sonia Rousse underorigin for the Bangui Magnetic anomaly (Central Africa). the AUF (Agence Universitaire de la Francophonie) fundingTectonophysics, 212, 45-58.was appreciated. As well as the involvement of Dr MohamedGodivier R., and Le Donche L., 1962. Rseau magntique Sobh from Institute of Geophysics and Geoinformatics, TUramen au 1er Janvier 1956. Rpublique Centrafricaine, Tchad Bergakademie Freiberg, Germany. Meridional. Tectonophyics, 212, 45-58Godivier R., Vassal A., 1980. Anomalie Magnetique en Centrafrique: References un modle gophysique. Fonds Documentaire ORSTOM 9p.Haggerty S. E., 2014. Carbonado diamond. Review of properties Abdelsalam, M.G., Liegeois, J.P., Stern, R.J., 2002. The Saharanand origin. Gems & Gemology, 53, 168-179.metacraton. Journal of African Earth Sciences, 34, 119136.Hemant K., Maus S., 2005. Geological modelling of the new https://doi.org/10.1016/S0899-5362(02)00013-1. CHAMP Magnetic Anomaly maps using a geographical Alexandrov, E.A., 1973. The Precambrian banded iron formationsinformation system technique. Journal of Geophysical of the Soviet Union. Econ. Geol. 68, 10351062. https://doi. Research, 110, 1-23. https://doi.org/10.1029/2005jB003837org/10.2113/gsecongeo.68.7.1035. Hemant, K., 2003. Modelling and Interpretation of Global Aubreya Adams, Wiens Douglas, Nyblade Andrew A., GarrettLithospheric Magnetic Anomalies. PhD Thesis, Freien Euler G., Patrick Shore, Tibi Rigobert, 2015. LithosphericUniversity, Berlin, 152p.instability and the source of the Cameroon Volcanic Line:Klokocnik J., Kostelecky J., Novak P., Wagner A. C., 2010. Evidence from Rayleigh wave phase velocity tomography.Detection of Earth impact craters aided by the detailed Journal of Geophysical Research, Solid Earth, 120, 1708-1727.global gravitational model EGM2008. Acta Geodyn. Geomater. https://doi.org/10.1002/2014JB011580. 7(157), 71-97.49 PREVIEW FEBRUARY 2022'