 | | Journal (article/letter/editorial) | | e r a i II est possible de distinguer de bas en haut des coupes 6tudi6es (coupes naturelles, puits d'hommes...poissons>> comparable ~ celle qui a 6t6 d6crite/t Moanda au Gabon (Perseil et Bouladon 1971; Nahon et al. 1983)...front d'alt6ration (Fig. 1). On y d6crit de bas en haut: - (i) une unit6 mangan6sif6re inf6rieure d'environ...muscovites (phengites) peuvent ~tre altdres en kaolinite. T o u s l e s stades existent entre b) Etude...modifi6) 126 Si [] Kaolinite • Muscovite 0 Muscovite alteree • Melange Kaolinite Chlorite "Y~ Chlorite |  | Parc, Sylvie, Nahon, Daniel, Tardy, Yves, Vieillard, Philippe (1989) Estimated solubility products and fields of stability for cryptomelane, nsutite, birnessite, and lithiophorite based on natural lateritic weathering sequences. American Mineralogist, 74 (3-4) 466-475 | Journal (article/letter/editorial) | | rhodochrosite + illite - cryptomelane * kaolinite - nsutite + kaolinite - lirhiophorils - gibbsite manganesesilicates...manganesesilicates - birnessite * kaolinite - nsutite * kaolinite - pyrolusite + kaolinite - kaolinite * gibbsite. Gibbs...on manganiferoussedimentary rocks in the Moanda area (Gabon), and in the Azul area (northern Brazil)...The second profile occurs at the Moanda weathering ore-body, in Gabon. The Precambrian sedimentary parent...15 to 25o/odetrital muscovite and authigenetic kaolinite,0 to l0o/odetrital feldspar, 5olopyrite, and organic |  | | Journal (article/letter/editorial) | | EYLANDT, NORTHERN TERRITORY, AUSTRALIA BERNHARD Department PRACEJUS. of Geology and Geophysics, BARRIE...romanechite (psilomelane), todorokite, quartz, kaolinite, goethite and hematite. Probably with the exception...example, the highest grade ores at the giant Moanda deposit in Gabon include supergene manganite, pyrolusite...makes Groote Eylandt an analogue of the Moanda deposit in Gabon. The importance of supergene processes...cryptomelane, nsutite, kaolinite Pyrolusite, cryptomelane todorokite, kaolinite, Feoxihydroxides 78 |  | Nahon, Daniel, Beauvais, Anicet, Boeglin, Jean-Loup, Ducloux, Jacques, Nziengui-Mapangou, Pacome (1983) Manganite formation in the first stage of the lateritic manganese ores in Africa. Chemical Geology, 40 (1) 25-42 doi:10.1016/0009-2541(83)90089-x | Journal (article/letter/editorial) | | 3COMILOG, Service Prospections Extdrieures, Moanda (Gabon) (Received June 23, 1982; revised and accepted...whereas in a weathered carbonate sequence (Moanda, Gabon) manganite replaces thodochrosite. In both areas...tephroitites. The second is the minefield of Moanda in Gabon where the weathering profile overlies Precambrian...is replaced by a mixture of Mn-oxyhydroxide + kaolinite. Pa ren t - m i n e r a l s Tephroite crystals...CARBONATE ROCKS OF MOANDA (GABON) The l>recambrian parent-rock of the Moanda minefield is a black |  | | Journal (article/letter/editorial) | | (kaolinitic horizons) to form Mn nodules in which kaolinite is dissolved. This process provides A1 which combines...former des nodules de mangan&e dans lesquels la kaolinite est dissoute lib&ant de t'aluminium qui se combine...Part of it associates with released AI to form kaolinite cogenetically with ferruginous oxyhydroxides....be formed either from parent minerals or from kaolinite crystals. Thus, the laterite-forming-product consists...oxyhydroxides, of clay minerals (essentially kaolinite) and sometimes of relics of parent minerals which |  | | Journal (article/letter/editorial) | | ACCOMPANYING PHASES IN A LATERITIC PROFILE OF MOANDA, GABON M. AMOURIC,I S. PARC,2 AND D. NAHON2 I...the principal minerals in the matrix (illite, kaolinite, and goethite) were examined for a better understanding...mixtures of manganite and pyrolusite from the Moanda sequence (Gabon) were examined by HRTEM in an effort to...manganiferous sedimentary rocks in the Moanda minefield, Gabon. A global cross section of this profile...manganite and pyrolusite occurred at the base of the Moanda sequence. The samples consisted of MANGANIFEROUS |  | | Book | | ........................ 97 Example of the Moanda (Gabon) Sedimentary Manganese Deposit Enriched by Lateritization...142 Laterites in a Humid Equatorial Climate:the Gabon Example ....... 145 Conclusions and Perspectives...(PE), Brazil DANIEL JEANNETTE SAM CHAUDHURI Department of Geology, Kansas State University Manhattan...These secondary components are either gibbsite, kaolinite or smectites (low charge 2/1 clay minerals). This...small amount of neoformed minerals (gibbsite,kaolinite and smectites) also result from weathering of |  | Dubois, Manon, Lopez, Michel, Orberger, Beate, Gay, Aurélien, Moussavou, Mathieu, Pambo, Florent, Rodrigues, Sophie (2017) The 2.1 Ga-old injectite network of the Franceville Basin, Gabon: Architecture, origin and implications on manganese mineralization. Precambrian Research, 302. 255-278 doi:10.1016/j.precamres.2017.09.022 | Journal (article/letter/editorial) | | 1Ga-old injectite network of the Franceville Basin, Gabon: Architecture, origin and implications on manganese...1Ga-old injectite network of the Franceville Basin, Gabon: Architecture, origin and implications on manganese...1Ga-old injectite network of the Franceville Basin, Gabon: Architecture, origin and implications on manganese... Franceville, Gabon e COMILOG SA- Société du groupe Eramet, B.P. 27-28 Moanda, Gabon Bulletin: Precambrian...drill-core sections in the 2.1-Gaold Franceville basin, Gabon, provide evidence for a large-scale injectite network |  | | Report (issue) | | United States of America 1984 CIRCULAR 930-A Department of the Interior WILLIAM P. CLARK, Secretary...compiler), USGS; Ian Goldberg, South African Department of Mineral and Energy Affairs (MEA), Minerals...A. B. T. Werner and Jan Zwartendyk, Canadian Department of Energy, Mines and Resources (EMR), Mineral...of Mines and the Geological Survey of the U.S. Department of the Interior; the Geological Survey and the...the Mineral Policy Sector of the Canadian Department of Energy, Mines and Resources; the Federal Institute |  | Ruffet, G., Innocent, C., Michard, A., Féraud, G., Beauvais, A., Nahon, D., Hamelin, B. (1996) A geochronological and study of K-Mn oxides from the weathering sequence of Azul, Brazil. Geochimica et Cosmochimica Acta, 60 (12) 2219-2232 doi:10.1016/0016-7037(96)00080-4 | Journal (article/letter/editorial) | | (Received 13545 Aix-en-Provence Cedex 4, France Department of Geology, University of Washington, July 12...cryptomelane have been already observed at Moanda (Gabon) ( Nziengui-Mapangou, 198 1) , although direct...parent rock) are not yet entirely weathered into kaolinite (Fig. 5). K-micas persist in the upper part of...muscovite is entirely weathered into kaolinite, Al released by kaolinite weathering can feed lithiophorite...roches skdimentaires p&ambriennes. Gisements de Moanda (Gabon) et d’Azu1 (BrCsil). Th&se d’Universit& (Poitiers) |  | De Putter, Thierry, Liégeois, Jean-Paul, Dewaele, Stijn, Cailteux, Jacques, Boyce, Adrian, Mees, Florias (2018) Paleoproterozoic manganese and base metals deposits at Kisenge-Kamata (Katanga, D.R. Congo) Ore Geology Reviews, 96. 181-200 doi:10.1016/j.oregeorev.2018.04.015 | Journal (article/letter/editorial) | | East Kilbride, United Kingdom Ghent University, Department of Geology, Mineralogy and Petrology, Krijgslaan...Manganese Field (hereafter 54 KMF), the Moanda deposits of Gabon and the Serra do Navio deposit in Brazil...Kisenge-Kamata area is located in the former Katanga province, 250 km west of 67 Kolwezi (Fig. 1a). Geologically...1973). In the region of Mwene Ditu (Kasai Oriental Province, ~400km 91 North of Kisenge; Fig. 1a), where...such as Mwene Ditu (Fig 1; Kasai Oriental 128 Province; Morelli & Raucq, 1961), for which an E-W elongated |  | Bankole, Olabode M., El Albani, Abderrazak, Meunier, Alain, Gauthier-Lafaye, François (2015) Textural and paleo-fluid flow control on diagenesis in the Paleoproterozoic Franceville Basin, South Eastern, Gabon. Precambrian Research, 268. 115-134 doi:10.1016/j.precamres.2015.07.008 | Journal (article/letter/editorial) | | Paleoproterozoic Franceville Basin, South Eastern, Gabon Olabode M. Bankole a,∗ , Abderrazak El Albani a...Basin Gabon a b s t r a c t The Paleoproterozoic (∼2.15 Ga) Franceville Basin, South Eastern Gabon, is...Franceville Basin (Fig. 1), located in south-eastern Gabon, represents one of the world oldest petroleum systems...Regional geological map of Franceville Basin in Gabon (Ossa et al., 2013) that shows location of the study...Lastoursvilles, and Okonja basins in the South Eastern Gabon (Gauthier-Lafaye and Weber, 1989, 2003; Gauthier-Lafaye |  | Ossa Ossa, Frantz, El Albani, Abderrazak, Hofmann, Axel, Bekker, Andrey, Gauthier-Lafaye, François, Pambo, Florent, Meunier, Alain, Fontaine, Claude, Boulvais, Philippe, Pierson-Wickmann, Anne-Catherine, Cavalazzi, Barbara, Macchiarelli, Roberto (2013) Exceptional preservation of expandable clay minerals in the ca. 2.1Ga black shales of the Francevillian basin, Gabon and its implication for atmospheric oxygen accumulation. Chemical Geology, 362. 181-192 doi:10.1016/j.chemgeo.2013.08.011 | Journal (article/letter/editorial) | | 2.1 Ga black shales of the Francevillian basin, Gabon and its implication for atmospheric oxygen accumulation...Barbara Cavalazzi a,g, Roberto Macchiarelli h,i a Department of Geology, University of Johannesburg, Auckland...Université de Poitiers, 86022 Poitiers, France c Department of Geological Sciences, University of Manitoba...Strasbourg, France e Direction Mine, COMILOG SA, BP 27-28 Moanda, Gabon f Géosciences Rennes, UMR 6118...ca. 2.1 Ga Francevillian Group in southeastern Gabon. The FB Formation of the Francevillian Group is |  | | Journal (article/letter/editorial) | | phase, e.g., deposits in Africa (South Africa, Gabon, Ghana, Congo), Brazil, Australia, India, Sweden...medium and large manganese deposits (e.g., Moanda deposit, Gabon) (Weber, 1970). Significant Mn reserves...the Marra Gamba BIF, Hammersley basin, Pilbara province (Western Australia). The weathering profiles of...manganese oxides in the Pilbara manganese ore province (Western Australia) located 400 km SE of Port...direction, respectively. The largest deposits in this province are Rippon Hill, Woodie Woodie, Ant Hill, Hitek |  | Polgári, M., Hein, J.R., Vigh, T., Szabó-Drubina, M., Fórizs, I., Bíró, L., Müller, A., Tóth, A.L. (2012) Microbial processes and the origin of the Úrkút manganese deposit, Hungary. Ore Geology Reviews, 47. 87-109 doi:10.1016/j.oregeorev.2011.10.001 | Journal (article/letter/editorial) | | Mangán Ltd. Úrkút, Külterület 1, H-8409, Hungary d Department of Mineralogy, Geochemistry and Petrology, University...shale-hosted Mn-carbonate deposits include Moanda, Gabon (Early Proterozoic, 2.095 Ga), Wafangzi, Gaoyan...Molango—Mexico, Okita, 1987; Okita and Shanks, 1988; Moanda—Gabon, Hein et al., 1989; Úrkút—Hungary, Polgári et...exploited ore volume is 436,000 m 3 and an open-pit mine site covered 1.81 km2 (Fig. 6a). The (ii) black...lithostratigraphy (b) of the Mn carbonate ore bed (Úrkút Mine, Shaft No. III, + 180 m) (c) A–A and B–B sections |  | | Book | | 11. Conclusion 2.2.2. Model Test Area: Moanda Deposit, Gabon, West Africa 2.2.2.1. Introduction 20 20...the Postmasburg Region, Griqualand West, Cape Province, South Africa 3.3.1. Geological Setting 3.3.2...author also wishes to thank I.v. Reid, Research Department Manager, for the discussion of geological problems...which occur white, red, and yellow predominantly kaolinite cIays, and sand cIays, incIuding the layer of...eream-eolored, and white clays of predominant kaolinite eomposition. The thickness of the ore bed varies |  | | Report (issue) | | Future Supply Professional Paper 1802–L U.S. Department of the Interior U.S. Geological Survey Periodic...pdf. Cover. Photograph of the Mamatwan open pit mine in South Africa. The black manganese layer is about...folded layering is shown by the shapes of the various mine benches. Lighter material in the background is waste...Paper 1802– L U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior RYAN...............................................L18 Mine Waste Characteristics ......................... |  | | Journal (article/letter/editorial) | | minerals while hematite, pyrolusite, boehmite and kaolinite are dehydrated minerals. Hydrated minerals appear...1971). This is probably due to the presence of kaolinite which controls the chemical composition of the...goethites of ferricretes and other soils in which kaolinite is present. Compositions range from 18 to 27 mole...than goethite and both are less aluminous when kaolinite and quartz are present than when gibbsite forms...solubility of aluminous minerals, that is gibbsite and kaolinite. It turns out that the relative stability fields |  | | Journal (article/letter/editorial) | | 2COMILOG, Service Prospections Ext~rieures, Moanda (Gabon) (Received March 22, 1983; revised and accepted...transformed into a mixture of Mn-oxihydroxide + kaolinite, but garnets are unaltered during this stage of...with nests of chlorite, which partly alter into kaolinite + todorokite (Nahon et al., 1983). The birnessite...1953. The manganese mineralizations at the Merid-Mine, Minas Gerais, Brazil. Ph.D. Thesis, Harvard University...Zi~mougoula, en CUte d'Ivoire et gisement de Moanda, au Gabon). Thesis, University of Poitiers, Poitiers |  | Santos, Felipe Holanda dos, Amaral, Wagner da Silva, Konhauser, Kurt, Martins, Douglas Teixeira, Castro, Marco Paulo de, Queiroga, Glaucia Nascimento, Chi Fru, Ernest, Andersen, Morten B. (2021) Unraveling sedimentary precursors and metal enrichment of high-grade metamorphosed manganese-rich rocks from the Borborema Province, northeastern Brazil. Ore Geology Reviews, 137. 104283pp. doi:10.1016/j.oregeorev.2021.104283 | Journal (article/letter/editorial) | | metamorphosed manganese-rich rocks from the Borborema Province, northeastern Brazil Felipe Holanda dos Santos...Estadual de Campinas, Campinas, SP, Brazil c Department of Earth & Atmospheric Sciences, University of...R A C T Keywords: Paleoproterozoic Borborema Province Manganese ore Sedimentary protolith Anoxic sediments...Lagoa do Riacho manganese deposit in the Borborema Province is central to unravelling the genesis of Paleoproterozoic...Paleoproterozoic deposits in Ghana, Gabon and South Africa in the Nsuta, Moanda and Kalahari manganese fields |  | Molnár, Zsombor, Polgári, Márta, Hein, James R., Józsa, Sándor, Fekete, József, Gyollai, Ildikó, Fintor, Krisztián, Bíró, Lóránt, Szabó, Máté, Rapi, Sándor, Forgó, Péter, Vigh, Tamás (2017) Fe-Mn oxide indications in the feeder and mound zone of the Jurassic Mn-carbonate ore deposit, Úrkút, Hungary. Ore Geology Reviews, 86. 839-855 doi:10.1016/j.oregeorev.2016.11.005 | Journal (article/letter/editorial) | | ore deposit were studied using 45 samples (Úrkút Mine, Shaft III, deep level). Microstructural and textural...meters to tens of meters thick observable in the mine between the footwall limemarlstone and the ore bed...level of the Úrkút manganese mine, set 5 was collected at the Eplény mine from a similar geologic position...occurs mainly in the clay mineral-rich lenses. Kaolinite and chlorite occur as trace components. Apatite...(Mexico; Okita & Shanks, 1988; Okita, 1992), Moanda (Gabon; Hein et al., 1989), Uralian occurrences (Maslennikov |  | | Journal (article/letter/editorial) | | phases minerales, l’hydroxyde ferrique et la kaolinite. L’etude des roches alttrees et des sols montre...thermodynamic properties of ferric hydroxide and kaolinite are consistent with this hypothesis, though microsystems...conduit Q une monosiallite, mineral du groupe de la kaolinite oti Si/Al = 1. Enfin, la troisitme dtape se traduit...I1 Ctablit la sequence roche mere - smectite - kaolinite - gibb1267 site qui sera plus ou moins respect&e...l’albite conduit a la sequence: puis gibbsite - kaolinite - Na-montmorillonite, Cquilibre avec les feldspaths |  | | Journal (issue) | | Cassitérite. macle cyclique 2,8 x 2 x 2, 1 cm Mine de La Villeder, Morbihan Collection privée Photo...DANS 1A PROVINCE W-SN ARMORICAINE par Eric GLOAGUEN et Yannick DAIN 0 HISTORIQUE DE 1A MINE par Y annick...Hors-Série n°2 (La Barytine en France), n°3 (La mine d'or de Salsigne) et n°4 (La radioactivité et les...Hors-Série de cette fin d'année 2001 est un retour à la mine dans une région qui ne nous est un peu moins inconnue...wolframite. Paradoxalement, c'est dans une ancienne mine de plomb argentifere que nous vous faisions découvrir |  | Fisher, D. Jerome, Bloss, F. Donald, Manley, Frederick H., Power, W. Robert, Bailey, Edgar H., Marsden, Ralph W., Sinkankas, John, Keller, W. D., Dubins, M. Ira, Baur, Werner H., Horibe, Yoshio (1974) BOOK REVIEWS. American Mineralogist, 59 (9-10) 1142-1149 | Journal (article/letter/editorial) | | iron-formation and iron ores of Australia, Brazil, Canada, Gabon, India, Liberia, Mauritania, Morocco, Sweden, Union...States of America and manganese deposits of Brazil, Gabon, the Guianas, India, Morocco, and the U.S.S.R. This...Belinga iron ore deposit in the Mekambo District, Gabon. H. Gruss presents an interesting comparison of...informative paper concerning the extensive Moanda manganese depositsof Gabon which occur in unmetamorphosed,Precambrian...of such fundamentals as the basal spacing of kaolinite being about 7A as well as the latest publications |  | | Journal (article/letter/editorial) | | samples (BF96-190; Table 1a). Pisolites consist of kaolinite and cryptomelane in concentric banded structure...results thus in Mn- and K-leaching, formation of kaolinite, and an increase of porosity (Figs. 2b and 4b)...b), which is associated with the formation of kaolinite (Fig. 3), hematite and goethite in successive...leaching of manganese and consecutive formations of kaolinite and iron oxides in matrices are the result of...accumulations mainly occur in Mn-leached domains of the kaolinite and goethite-rich matrices and of manganese pisolites |
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