The Elogo region has been subjected to craft industry and semi-industrial mining for gold-bearing placers, since the colonial times. It is actually undergoing an intensive exploration for a primary gold deposit. The goal of this study is to contribute to the exploration of the primary gold deposit in the Elogo Region (North-West of Congo Republic). The methodology consisted of characterization of placers deposits by their lithology, mineralogy and the gold grains shape, in order to constrain the source of gold with the respect to the local geology. The results obtained show that alluviums are polygenic and yields seventeen mineral species composed of zircon, olivine, magnetite, ilmenite, gold, garnet, rutile, coltan, cassiterite, monazite, apatite, amphibole, tourmaline, pyrite, limonite, chromite, and amphibole. The morphoscopy of gold grain shows single grains and grains with quartz inclusions that suggest their relationship with quartz veins. The gold grains are flattened, sub-flattened, and rounded. The northern region of Elogo characterized by a dominance of coarser quartz-included gold grains indicates a proximal proparte origin (less than 50 m), while the southern region, showing less coarse and more evolved grains with choc marks, appears to be associated with a distal pro-parte origin (more than 300 m). The multivariate statistical analysis shows seven classes of samples corresponding to the mineralogical paragenesis suggesting various sources, consisting of high-grade metamorphic, granitoids, pegmatites, basic and ultrabasic rocks, and BIFs that provided minerals to the placers. Gold mainly comes from hydrothermal quartz veins and probably from the peptization of gold from the weathering of sulfides occurring in the BIF. In the Elogo region, gold exploration for primary deposits should look for and follow the hydrothermal system developed in this region. Chemical analysis for the gold grains and associated minerals is necessary to better guide the proposed geochemical prospecting.
Jébrak, M. and Marcoux, E. (2008) Géologie des ressources minérales. Ed. Ressources Minérales et Faune du Quebec. Quebec, Canada, 667 p.
Prisca-Gaelle, B.àN., Ngouo, K.S., Rose, Y.F., Richard, T. and Séverin, K.D. (2021) Prospecting of Gold Mineralization Indices in the Eastern of Meiganga (Adamawa Region, Cameroon). Open Access Library Journal, 8, e7662. https://doi.org/10.4236/oalib.1107662
Herail, G. (1984) The Gold Flakes, Memory of the Piedmonts. Courier Centre National de Recherches Scientifiques, 57, 49-51.
Watha-Ndoudy, N. (1993) Morphological and Geochemical Characteristics of Gold Grains: Application to the Prospection of Placers of Mayoko (Congo). Institut National Polytechnique de Lorraine, Vandoeuvre-lès-Nancy, France, 174 p.
Townley, B.K., Hérail, G., Maksaev, V., Palacios, C., de Parseval, P., Sepulveda, F., Orellana, R., Rivas, P. and Ulloa, C. (2003) Gold Grain Morphology and Composition as an Exploration Tool: Application to Gold Exploration in Covered Areas. Geochemistry, Exploration, Environment, Analysis, 3, 29-38. https://doi.org/10.1144/1467-787302-042
Wrighton, T.M. (2009) Placer Gold Microchemical Characterization and Shape Analysis Applied as an Exploration Tool in Western Yukon. University of British Columbia, Vancouver, 349 p.
EL-Wekeil, S.S. and Gaafar, F.Sh. (2014) Mineralogical and Geochemical Studies of the Placer Deposits of Gebel El-Massaid Area, North Eastern Desert Egypt: As a New Occurrence for Gold Mineralization. Current Science International, 3, 108-121.
Ntiharirizwa, S. (2013) The Mineral Resource Potential of Burundi, North-East of the Kibarian Orogenic Belt, East-Central Africa. Laval University, Quebec, 120 p.
Nikiforova, Z.S., Gerasimov, B.B., Glushkova, E.G. and Kazhenkina, A.G. (2018) Indicative Features of Placer Gold for the Prediction of the Formation Types of Gold Deposits (East of the Siberian Platform). Russian Geology and Geophysics, 59, 1318-1329. https://doi.org/10.1016/j.rgg.2018.09.009
Aye, F., Bouladon, J., Picot, P. and Pouit, G. (1978) Quelques exemples d’apports de la minéralogie à la connaissance et la recherche des gites minéraux. In: Bulletin de Minéralogie, Vol. 101, Centenaire de la Société Francaise de Minéralogie et Cristallographie (SFMC), Paris, 139-147. https://doi.org/10.3406/bulmi.1978.7182
Bruni, Y. and Hatert, F. (2017) étude minéralogique de l’or et de ses minéraux accompagnateurs sur le pourtour du massif cambro-ordovicien de Serpont, Belgique. Bulletin de la Société Royale des Sciences de Liège, 86, 113-168. https://doi.org/10.25518/0037-9565.7243
Boudzoumou, F., Malounguila-Nganga, D., Diakubuka, E., Mouanda, Moumpossa R.S., Odongo, C., et al. (1993) Notice explicative de la carte géologique de la République du Congo au 1 : 1000000. Compilation, Ministère des Mines et Energie, Brazzaville, Congo, 1-2, 21-22.
Gatsé Ebotehouna, C., Xie, Y., Adomako-Ansah, K. and Qu, Y. (2021) Petrology, Geochemistry, and Zircon U-Pb-Lu-Hf Isotopes of Granitoides from the Ivindo Basement Complex of the Souanké Area, Republic of Congo: Insights into the Evolution of Archean Continental Crust. Geological Journal, 56, 4861-4887. https://doi.org/10.1002/gj.4219
Meloux, J., Bigot, M. and Viland, J. C. (1983) Plan minéral de la République Populaire du Congo. Ministry of Mines and Energy, Brazzaville, 734 p.
Parfenoff, A., Pomerol, C. and Tourenq, J. (1970) Grain Minerals: Study Methods and Determination. Masson et Cie, Paris, 578 p.
Broche, J., Casanova, R. and Loupe, G. (1997) Atlas of Mineral Grains: Identification by Color Photographs. Société pour le développement minier de la Cote d’Ivoire (SODEMI), Abidjan, 180 p.
Mhamdi, N.P., Achab, P. and Filali, P. (2005) Les sables titanifères du littoral d’Azemmour et de l’estuaire de l’Oum Er-Rbia (cote atlantique marocaine). Bulletin de l’Institut Scientifique, Section Sciences de la Terre, 27, 83-91.
Ciceri-Marchand, M.-F. (1974) Méthodes d’analyse multivarié dans la géographie anglo-saxonne, évaluation des techniques et des applications. Université Panthéon-Sorbonne, Paris, 168 p.
Malibangar, A., Lang, J. and Censier, C. (2001) Use of Heavy Minerals as Indicators of Alluvial Diamond-Bearing Paleoplacers in the Central African Republic (CAR) Use of Heavy Minerals as Indicators of Diamantiferous (Alluvial) Paleo-Placers in Central African Republic (CAR). Geological Society of France, 36, 43-58.
Baccini, A. (2010) Multidimensional Descriptive Statistics. Publications de l’Institut de Mathématiques de Toulouse, Université Paul Sabatier, Toulouse, 33 p.
Touhtouh, D.E. (2014) Application of Multivariate Statistical Analysis Methods to the Study of the Physicochemical Characteristics of Soils in Sais, Morocco. European Scientific Journal, 10, 140-158.
Laboundou R., (2014) L’orpaillage et son impact dans le secteur de Ngoyboma-Lebaye (District de Kéllé, Congo). Université Marien Ngouabi, Brazzaville, 37 p.
Herail, G., Fornari, M., Viscarra, G., Ruiz, J.A., Pozzo, L. and Dumont, J.F. (1991) The Golden Placers of Bolivia: Formation Environments and Geological Structure. Alluvial Gold Deposits, La Paz, 1-5.
Lanckneus, J. (1989) The Gold-Bearing Alluvial Placers of the Amazonian Plain of Madre de DIOS (SE of Peru). Bulletin de la Société Géographique de Liège, 25, 129-143.
Colin, F. (1992) Gold Traces the Chemical History of Lateral Alteration under Equatorial Forest. Université Aix-Marseille-III, Aix-en-Provence, 171 p.
Krupp, R.E. and Weiser, T. (1992) On the Stability of Gold-Silver Alloys in the Weathering Environment. Mineralium Deposita, 27, 268-275. https://doi.org/10.1007/BF00193397
Martini, J.E.J., Bowles, M. and Vecelinovic-Williams, M. (1994) Carte métallogénique de la République du Congo 1/1.000.000 Ministère des Mines et de l’Energie. Council for Geoscience, Pretoria, South Africa, 27 p.
Augustin, J. (2017) Study of Gold Mineralizations in the District of Mana, Burkina Faso. Hydrothermal Evolution of a Gold System and Tectono-Metamorphic Constraints. University of Quebec, Quebec, 355 p.
Wilson, E.E. (1961) Gold Placers and Placering in Arizona. State of Arizona Office of Geology and Mineral Technology, Geological Survey Branch, Bulletin 168. The Board of Regents of the Universities and State College of Arizona, Tucson, 65p.
Ouedraogo, T., Sawadogo, S., Kiéma, B. and Naba, S. (2021) Napelepera Gold Mineralization, SW Burkina Faso, West Africa: Establishment in an Eburnean Late-Orogenic Shear Zone. Africa SCIENCE, 20, 81-92.
Dana, J.W., Dana, E.S., Palache, C., Berman, H. and Frondel, C. (1952) The System of Mineralogy: Element, Sulfides, Sulfosalts, Oxides. Chapman and Hall, 7th ed., New York: Wiley, London, 808 p.
MacDonald, E.H. (1983) Alluvial Mining: The Geology, Technology and Economics of Placers. London and New York (Chapman and Hall), New York, 508 p.
Watha-Ndoudy, N. and Djama, L.M. (2004) Contribution of Radar Imagery to the Evaluation of the Gold Potential of the Mayoko Mining Area (Chaillu Massif, Congo Brazzaville). Annales de l’Université Marien Ngouabi, serie C, 5, 218-225.
De Tuder, P. (2011) Characterization of Gold Deposits Associated with the Archean Formations of the Mayoko Greenstone Belt, Massif du Chaillu, Republic of Congo. Lasalle Beauvais Polytechnic Institute, Beauvais, 77 p.
Allen, T.L., Hart, C.J.R. and Marsh, E.E. (1999) Placer gold and associated heavy minerals of the Clear Creek drainage, central Yukon: Past to present. In: Roots, C.F. and Emonds, D.S., Eds., Yukon Exploration and Geology 1998. Exploration and Geological Services Division, Yukon, Indian and Northern Affairs Canada, 197-214.
Wilson, A.F. (1984) Origin of Quartz-Free Gold Nuggets and Supergene Gold Found in Laterites and Soils—A Review and Some New Observations. Australian Journal of Earth Sciences, 31, 303-316. https://doi.org/10.1080/14400958408527933
Yeend, W., Shawe, D.R. and Wier, K.L. (1995) Gold in Placer Deposits. U.S. Geological Survey Bulletin 1857-G. In: Shawe, D.R., Ashley, R.P. and Carter, L.M.H., Eds., Geology and Resources of Gold in United States, U.S. Government Printing Office, Washington DC, 28 p.
Segupta, S.M. (1996) Introduction to Sedimentology. Oxford and IBH Publishing Co. Pvt. Ltd., New Delhi, 305.
Traoré, Y. (2017) Metallogenetic Study of the Syama Gold District (Mali): Comparative Analysis of Deposits Located on the Same Eburnean Lithospheric Structure. Paul Sabatier University-Toulouse III, Toulouse, 270 p.
Loen, J.S. (1994) Origin of Placer Gold Nuggets and History of Formation of Glacial Gold Placers, Gold Creek, Granite County, Montana. Economic Geology, 89, 91-104. https://doi.org/10.2113/gsecongeo.89.1.91