| Melgarejo, Joan C., Costanzo, Alessandra, Bambi, Aurora C.J.M., Gonçalves, Antonio O., Neto, Andrés B. (2012) Subsolidus processes as a key factor on the distribution of Nb species in plutonic carbonatites: The Tchivira case, Angola. Lithos, 152. 187-201 doi:10.1016/j.lithos.2012.06.024 | Journal (article/letter/editorial) | species in plutonic carbonatites: The Tchivira case, Angola Joan C. Melgarejo a, Alessandra Costanzo b,⁎, Aurora...Geologia, Universidade Agostinho Neto, Luanda, Angola a r t i c l e i n f o Article history: Received...Tchivira carbonatite, located 400 km south of Luanda (Angola), is a good example of a carbonatite body produced...Geological setting Most of the carbonatite complexes in Angola are found in the Lucapa structure (deVries Lapido-Loureiro...1200 km set of faults oriented NE–SW that cut the Angola–Congo craton (Issa Filho et al., 1991). Different | | Giovannini, Arthur L., Bastos Neto, Artur C., Porto, Claudio G., Pereira, Vitor P., Takehara, Lucy, Barbanson, Luc, Bastos, Pedro H.S. (2017) Mineralogy and geochemistry of laterites from the Morro dos Seis Lagos Nb (Ti, REE) deposit (Amazonas, Brazil) Ore Geology Reviews, 88. 461-480 doi:10.1016/j.oregeorev.2017.05.008 | Journal (article/letter/editorial) | laterite (10 m thick), the manganese oxides (mainly hollandite, with associated cerianite) occur as veins or...Craton, in the southeastern part of the Rio Negro Province (Santos et al. 2000). The basement is represented...manganiferous laterite, the main Mn-oxide mineral is hollandite, with pyrolusite occurring only in the lowermost...hematite (20% to 45%), goethite (30% to 68%), hollandite (~12%), and cerianite (1%). The parageneses in...in the wider Mn-bearing veins (1 cm) is hollandite, pyrolusite, goethite, and cerianite combined in different |
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