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The Itataia phosphate-uranium deposit (Ceará, Brazil) new petrographic, geochem...
Veríssimo, César Ulisses Vieira; Santos, Roberto Ventura; Parente, Clóvis Vaz; Oliveira, Claudinei Gouveia de; Cavalcanti, José Adilson DiasThe Itataia phosphate-uranium deposit is located in Santa Quiteria, in central Cear a State, northeastern Brazil. Mineralization has occurred in different stages and involves quartz leaching (episyenitization), brecciation and microcrystalline phase formation of concretionary apatite. The last constitutes the main mineral of Itatiaia uranium ore, namely collophane. Collophanite ore occurs in massive bodies, len...
Early to Late Paleoproterozoic magmatism in NE Brazil: The Alto Moxotó Terrane ...
Santos, Lauro Cézar Montefalco de Lira; Dantas, Elton Luiz; Santos, Edilton José dos; Santos, Roberto Ventura; Lima, Haroldo MonteiroThe Alto Moxotó Terrane is a Paleoproterozoic inlier within the Transversal Domain of the Neoproterozoic Borborema Province (NE Brazil). An isotopic and whole-rock geochemistry study has been performed in the Sucuru region (Paraiba State, NE Brazil) which revealed a long-lived evolution for this terrane. The first event is Siderian-aged, dated on 2.44 Ga, being represented by granitic to granodioritic banded or...
A hydrothermal karst-hosted U-P deposit related to Pangea break-up: Itataia dep...
Cavalcanti, José Adilson D.; Bessa, Maria Dulcinea M. R.; Santos, Roberto Ventura; Veríssimo, Cesar U. V.; Parente, Clóvis VazThe Itataia U-P deposit holds the second largest uranium reserve in Brazil. All of the uranium is contained within the microcrystalline structure of fluorapatite, which is the ore mineral of the collophanite bodies. The main lithology that hosts the mineralization is marble, and the collophanite occurs as massive bodies, stockwork vein, breccia, filling vugs in episyenites, and disseminated in host rocks. This ...
New facies model and carbon isotope stratigraphy for an ediacaran carbonate pla...
Ramos, Maria Eduarda Alves Ferreira; Giorgioni, Martino; Walde, Detlef Hans Gert; Carmo, Dermeval Aparecido do; Fazio, Gabriella; Vieira, Lucieth CruzThe Ediacaran is a period characterized by the diversification of early animals and extensive neritic carbonate deposits. These deposits are still not well understood in terms of facies and carbon isotope composition (δ13C). In this study we focus on the Tamengo Formation, in southwestern Brazil, which constitutes one of the most continuous and well-preserved sedimentary record of the late Ediacaran in South Am...
Isotopic analysis in teeth of contemporary brazilians with known diet and geolo...
Tinoco, Rachel Lima Ribeiro; Bastos, Murilo Quitans Ribeiro; Machado, Carlos Eduardo Palhares; Santos, Roberto Ventura; Rodrigues-Carvalho, ClaudiaDental anthropological data may provide valuable information about an individual's life, including age at death, health, signs of violence, ancestry, diet features, intentional modifications, and geographic origin. These pieces of information may be further detailed by diet and residential mobility estimates provided by isotopic analyses. The use of isotope data in the modern population is strongly dependent on...
Isótopos estáveis (C, O, S) e geoquímica de rocha total de carbonatitos da Prov...
Gomide, Caroline Siqueira; Brod, José Affonso; Vieira, Lucieth Cruz; Junqueira-Brod, Tereza Cristina; Petrinovic, Ivan AlejandroO presente trabalho investiga a relação entre a geoquímica de rocha total e a composição dos isótopos estáveis de carbonatitos pertencentes aos complexos alcalino-carbonatíticos de Tapira, Araxá, Salitre, Serra Negra, Catalão I e Catalão II da Província Ígneado Alto Paranaiba (APIP) e do Complexo Jacupiranga, da Província Grossa Ponta. Os complexos do Alto Paranaíba são ultrapotássicos, compreendendo bebedourit...
Carbon isotopes of Mesoproterozoic–Neoproterozoic sequences from Southern São F...
Santos, Roberto Ventura; Alvarenga, Carlos Josá Souza de; Babinski, Marly; Ramo, Maria Luiza S.; Cukrov, Neven; Fonseca, Marco AntônioThis paper addresses the carbon isotope variations observed on Mesoproterozoic and Neoproterozoic carbonates from the southeastern part of the Sa˜o Francisco craton and Arac¸uaı´ Belt, Brazil. Carbonates were collected across sections of the Mesoproterozoic Espinhac¸o Supergroup (Rio Pardo Grande Formation) and of the Neoproterozoic units of the Sa˜o Francisco basin, including: (i) dolomites and marls of the Ma...