 | | Journal (article/letter/editorial) | | Manganese deposits of the Oudalan province in the northeast of Burkina Faso, and Ansongo Inlier in eastern...Available online xxxx Keywords: West African craton Burkina Faso Ansongo Inlier Manganese Exploration a b s...crop out in the West African craton in Mali, Burkina Faso, Ghana and Cote d'Ivoire. There average grade...Béliata Mn oxide deposits in the Oudalan province (northeast of Burkina Faso), and Takavasita, Agualla and...occurrences in volcano–sedimentary belts in Burkina Faso, Ghana, Togo, and Cote d'Ivoire in the Paleoproterozoic |  | | Journal (article/letter/editorial) | | laser probe analysis on different generations of cryptomelane from Fe–Mn pisolites and their embedding lateritic...Ma only means that geochemical conditions for cryptomelane crystallisation were not fulfilled, but could...Ar/39Ar-geochronology; Cryptomelane; Lateritic pisolites; Paleoclimate; Planation landsurface; Burkina Faso; West Africa...heating analyses on different generations of cryptomelane identified in those facies. The main purpose...formations capping stepped landsurfaces of the region, e.g., bauxites, and the Paleogene climatic changes |  | | Journal (article/letter/editorial) | | manganese oxides from the hollandite group, such as cryptomelane (K1-2Mn8O16, nH2O), using 40Ar/39Ar argon-ion...deposit of Tambao (northern Burkina Faso), a present unexploited deposit among the cryptomelane-richest...collected from the massive 80-m high Mn-rich hill at Tambao. A detailed petrographical study shows that these...formations are composed of successive Na-rich cryptomelane layers, with Na/(Na 1 K 1 Ba) up to 20%. Seven...most external layers. The integrated rates of cryptomelane precipitation are estimated at 1 and 5 mm/Ma |  | | Journal (article/letter/editorial) | | al. (1992 and 1994) and Ruffet et al. (1996). Cryptomelane is well represented in numerous lateritic manganese...underlying manganese crust of the Tambao deposit (northern Burkina Faso). Geological setting and development...development of the pisolitic formations The Tambao manganese deposit consist of two 80 meters high hills mainly... F[6. 1. Schematic section of the main hill of Tambao manganese deposit showing the different lateritic...solutions. The manganese oxides dominated by cryptomelane are then replaced in the matrix by gibbsite |  | | Journal (article/letter/editorial) | | weathering history of the Central African Great Lakes Region – Tectonics drives, climate assists Thierry De...weathering history of the Central African Great Lakes Region – Tectonics drives, climate assists, Gondwana Research(2020)...weathering history of the Central African Great Lakes Region – tectonics drives, climate assists Thierry De...Katanga Province) and Mwene-Ditu (former Kasai Province). For the present study, cryptomelane-rich samples...are within a range of c. 77 Myr to c. 2 Myr. Cryptomelane formation took place at c. 76.4 Ma, c. 59.6 |  | | Book | | Components 2.2.1.9. K-Ar Age of the Mn Oxyhydroxide (Cryptomelane) Ores 2.2.1.1 O. Problem of Genesis 2.2.1.11...Deposits (Nsuta, Ghana; Mokta, Cöte d'Ivoire; Tambao, Burkina Faso (Upper Volta» 2.2.3.1. Geological Setting...Alteration 2.2.3.2.1. Nsuta 2.2.3.2.2. Mokta 2.2.3.2.3. Tambao 2.2.3.3. Mineralogy and Geochemistry of the Late...General characteristics 2.2.3.3.2. Mokta 2.2.3.3.3. Tambao 2.2.3.3.4. Nsuta 2.2.3.4. Features of the Protore...Paleokarst: Deposits of the Postmasburg Region, Griqualand West, Cape Province, South Africa 3.3.1. Geological |  | | Journal (article/letter/editorial) | | dans t rois gisements d'Afrique de I'Ouest Mokta, Tambao, Nsuta E. A. Perseil Laboratoire de Mineralog:ie...Gisements de manganese: A: Mokta. B: Nsuta. C: Tambao . . ,. . . . Par l'analyse min~ralogique...d'Afrique de l'Ouest; Tambao, dans la zone sah~lienne. Si l'on dolt tenir Mokta et Tambao comme de petits gisements...plus marqu6 ~ Tambao off apparaissent des gneiss fins et des amphibolites..A Nsuta et ~ Tambao, des intrusions...rhodonite ou la tTphro'ite. La rhodochrosite domine ~ Tambao et Nsuta] la spessartite ~ IViokla. Les trois gisements |  | | Journal (article/letter/editorial) | | northward during Cenozoic time. In addition, cryptomelane and other K-Mn oxides can be dated by K-Ar and...Les Baux in the Alpilles range of the Provence region, southeastern France. The town is named from a...(CIA-K) Isotopic dating of Mn-oxide minerals Cryptomelane and other manganese oxides can be directly dated...which is now too dry for deep weathering in Burkina Faso (Fig. 4A) but not in Brazil (Fig. 4B). Further... Putative 3430 Ma “laterites” from the Pilbara region of Western Australia (Ohmoto et al., 2007) are |  | | Journal (article/letter/editorial) | | different for samples from cuirass. In the group cryptomelane, coronadite, hollandite the ratio: (Ba, K, Pb)/H20...starting at low temperature for romanechite and cryptomelane and higher temperature for coronadite and hollandite...romanechite and coronadite than for cryptomelane. Romanechite, cryptomelane, and coronadite present a great...africains Dans les grands gisements africains (Tambao, Haute Volta, Mokta-Cdte d'Ivoire, Moanda-Gabon)...Roman6chRes de la zone de cuirasse du gisement Tambao (Haute Volta) - (Collection G. Grandin) Analyste |  | | Journal (article/letter/editorial) | | is transformed into nsutite along with minor cryptomelane. These latter minerals can locally evolve into...garnets; B = birnessite matrix; NC = nsutite + cryptomelane matrix replacing secondary birnessite. programs...formed birnessite. Minute zones of nsutite + cryptomelane matrix begin to evolve in microfissures and...traversing the birnessite matrix. The nsutite + cryptomelane matrix rapidly develops at the expense of birnessite...lithiophorite in the transforming mass. The nsutite + cryptomelane matrix consists of a cryptocrystalline phase |  | | Journal (article/letter/editorial) | | from an aggregate of plates from Rengersdorf. region. Samples from the Buruktal, Shcherbakov, and Kempirsai...of lithio phorite from the Moa deposit (Ovente Province, Cuba) and Co-Ni-asbolan and Co-Ni-lithiophorite...considerably more rarely than psilomelane (especially cryptomelane). This is clearly no accident. We found the...FIGURE 8. Lithiophorite in intergrowth with cryptomelane, Saxony (East Germany). FIGURE 7. Lithiophorite...which often form intergrowths with cryptomelane (Fig. 9). In the region of Groot Eylandt (Australia), lithiophorite |  | | Journal (article/letter/editorial) | | epigenic replacement: The quartz is replaced by cryptomelane, while the garnets may remain unweathered. The...des grenats. Quelques 6chantillons du gisement de Tambao, dans la r6gion sah61ienne du nord de la Haute-Volta...de Mokta, 5 fi 50 g pour l'6chantillon HV 16 de Tambao. I1 varie assez largement dans un m~me gisement...p61e grossulaire, jusqu'/~ 19% pour les grenats de Tambao, ne d6passant pas 7,5% pour les grenats de Mokta...grenats. 1,2,3: Mokta (SS68) grenats de 40 g - 4,5,6: Tambao (HV16) nats de 10 ~ 20 ~t 10,11:Borumba (EEl) 1 |  | | Book | | Semi-Arid Regions: the Brazilian Sertao and the African Sahel .................... . . 157 1 Introduction ....plasma. To what extent these processes affect any region on earth depends on the processes involved, on...also found in the Ifni granite of the Anti-Atlas region, Morocco, for instance. First case: calcite replaces...barite in certain Parna soi ls of the Murrumbidgee region, New South Wales.Aust JSci 20:274- 275 Bech J,...mulations calca ires dans les limons de Matmata de la region de Ga bes en Tunisie.Sci Geol Bull (Strasb) 37:387-398 |  | | Report (issue) | | Cogley, 1987). The large low shear wave velocity province (LLSVP) (Garnero et al., 2007) in the deep mantle...straddling the eruption of the Karroo large igneous province (LIP) at 183 Ma. Pangea had been assembled ca...outline of a currently large low shear wave velocity province (LLSVP) near the base of the mantle (mapped tomographically...eruption: A—Afar; CAMP—Central Atlantic Magmatic Province; D—Deccan; K—Karroo; Ker—Kerguelen; M—Marion;...intercalaire and the Hamadien of the Sahara and Sahel, illustrate the composite nature of the African |  | | Journal (article/letter/editorial) | | Digital elevation map showing landscape of the Zunyi mine and surrounding areas. Data are from International...Blocks during the Triassic (GBGMR, 1987). This region is characterized by a humid subtropical climate...bands of multiple cryptomelane generations. (b) Alternating growth bands of cryptomelane, nsutite, pyrolusite...pyrolusite, and lithiophorite. (c) Cryptomelane occurring along interlayered fractures in primary Mn-protore...generations of cryptomelane veins. (e) Crosscutting relationship of two generations of cryptomelane. Goethite |  | | Report (issue) | | given to a plant that would use ore from a future mine in the Carajas regon in Brazil. Gabon is also considering...development of the Azul deposits in Brazil and the Tambao deposit in Upper Volta depends upon the construction... ),;J",>-~ AUSTRALIA r?''A f'~ ·Groote Eylandt mine~·,; \ ,,..-··· '\ }... _,,,.r·:.,.• ,.j J ·· ...TABLE mine (1959), the Mamatwan mine (1964), the Wessels mine (1973), the Middelplaats mine (1979),...the Black Rock mine, the world manganese production accounted for by the Smartt mine (which opened in |  | 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) | | solubility productsand fields of stability for cryptomelane,nsutite, birnessite,and lithiophorite basedon...the poorly crystallized minerals birnessite, cryptomelane, nsutite, and lithiophorite are the major manganeseoxides...are the following: rhodochrosite + illite - cryptomelane * kaolinite - nsutite + kaolinite - lirhiophorils...crystallochemicalrefinements for birnessite, cryptomelane, and nsutite at the time when AG! values were...and cryptomelane). The purpose of this study is to estimate AG! values for nsutite, cryptomelane, birnessite |  | | Journal (article/letter/editorial) | | minerals found on the island are pyrolusite, cryptomelane, romanechite (psilomelane), todorokite, quartz...include supergene manganite, pyrolusite and cryptomelane derived from the dissolution and re-deposition...depth in the Cretaceous sediments (Slee, 1980). Cryptomelane is the major mineral to have been deposited...Cretaceous fault block movements have occurred in the region (Frakes, 1979 ) . The basement rocks are overlain...scale cross-bedding Pyrolusite, todorokite cryptomelane, birnessite, nsutite, psilomelane, lithiophorite |  | | Journal (article/letter/editorial) | | the piemontite-bearing horizons of the St. Marcel Mine, Praborna (Aosta Valley, Italy). These oxides are...the conclusion that these oxides belong to the cryptomelane-hollandite-coronadite isostructural series....Alma-Ata 230 p. en russe (1974) Martin-Vernizzi, S.: La mine de Praborna (Val d'Aoste, Italic) Une s6rie mangan6sif6re...dans trois gisements d'Afrique de l'Ouest: Mokta, Tambao, Nsuta. Mineral. Deposita 13:295 - 311 (1978) Perseil |  | | Report (issue) | | 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...............................................L18 Mine Waste Characteristics ........................................................................L22 Mine Closure...................................................L11 Photograph of the Mamatwan open pit mine in South Africa ............................... |  | | Journal (article/letter/editorial) | | iron and manganese oxides (mainly goethite, cryptomelane and nsutite). Only in the materials associated...rggion ou de gisements comme ceux de Grand-Lahou, Tambao ou Nsuta (Perseil et Grandin, 1978): la nature...au nord du Blafo, remanient de petits d&bris de mine- Les Mingralisations Mangangsif~res Volcano-s~dimentaires...darts trois gisements d'Afrique de l'ouest: Mokta, Tambao, Nsuta. Mineral. Deposita 13, 295-311 (1978) Vachette |  | Deng, Xiao-Dong, Li, Jian-Wei, Vasconcelos, Paulo M., Cohen, Benjamin E., Kusky, Timothy M. (2014) Geochronology of the Baye Mn oxide deposit, southern Yunnan Plateau: Implications for the late Miocene to Pleistocene paleoclimatic conditions and topographic evolution. Geochimica et Cosmochimica Acta, 139. 227-247 doi:10.1016/j.gca.2014.04.036 | Journal (article/letter/editorial) | | landscape evolution. Weathering profiles in the Baye Mn mine are dominated by 20-30 m thick saprolites, which...older weathering profiles, now dismantled, in the region. Manganese oxide 40 Ar/39Ar ages of the Baye...et al., 1989). The Mn oxides are dominated by cryptomelane, with minor amounts of pyrolusite, lithiophorite...and hollandite (Table EA1 and Fig. 4 and 5). Cryptomelane occurs as fine crystalline masses or as microscopic...Secondary electron image and XRD patterns show that cryptomelane is well crystallized (Fig. 5) and typically |  | | Journal (article/letter/editorial) | | sequence of transformation (rhodochrosite ~ cryptomelane nsutite ~ pyrolusite) by pseudomorphic replacement...undergo a true retromorphic evolution toward cryptomelane, which is subsequently epigenized by lithiophorite...recycling of the Mn to the bottom of the profiles. Cryptomelane and lithiophorite constitute the more stable...Planche 1 a Remplacement pseudomorphique de la cryptomelane (C) par la nsutite (N). On note la structure...r~flechie naturelle b Recristallisations de cryptomelane (C), nsutite (N) et ramsdel[ite (R) au sein |  | | Journal (article/letter/editorial) | | oxides (i.e., cryptomelane) in the weathering profiles of each paleosurface from the Tambao type locality...locality (Fig. 1(a)) in Burkina Faso (synthesis in Beauvais and Chardon, 2013). Surface and core samples were |  | 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) | | be followed by the formation of birnessite, cryptomelane, nsutite and pyrolusite (Roy, 1968). The limited...fact, the other "dioxides", such as birnessite, cryptomelane or nsutite are rarely considered in that type...thermodynamic values. Manganite may only exist in a pH region > 7.5 (at 25°C and 1 atm, for log [Mn 2÷] = -6...1953. The manganese mineralizations at the Merid-Mine, Minais-Gemis, Brazil. Ph.D. Thesis, Harvard University...dans trois gisements d'Afrique de l'Ouest: Mokta, Tambao, Nsuta. Miner. Deposita, 13: 295--311. Roy, S. |
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