Papers by Moacyr Moura Marinho
Revista Brasileira de Geociências
Complex is one of the intrusions from the Alkaline Province of the South Bahia State. Which host ... more Complex is one of the intrusions from the Alkaline Province of the South Bahia State. Which host the blue coloured biotite-sodalite-syenite ore. The Pb-Pb isotopic results for single zircon from the sodalite-syenites of this complex results an age of 696 ± 3 Ma, which is interpreted as the minimum formation age for the blue-sodalite-ore.
Journal of South American Earth Sciences, 2021
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Precambrian Research, 1985
The granite-greenstone terrain of central~outhern Bahia belongs to the Sao Francisco craton and i... more The granite-greenstone terrain of central~outhern Bahia belongs to the Sao Francisco craton and is a key area for the understanding of the Archaean and lower Proterozoic of South America. In addition, it is in an area of great metallogenic potential. The granitic-migmatitic-gneissic basement complex is intimately associated with low to medium grade metasedimentary and metavolcanic sequences, such as the Brumado, Umburanas and Contendas-Mirante. In all of these sequences the metasedimentary rocks predominate, although acid metavolcanics constitute a significant fraction of the Contendas sequence and ultrabasic rocks occur in several isolated units. Early Archaean granitoid rocks (Rb-Sr isochron ages older than 3 Ga) occur in some regions such as Mata Verde-Boa Vista, Lagoa do Morro and Sete Voltas. Extensive granitic intrusive activity, with associated medium grade metamorphism and metasomatism, occurred in most of the area ~ 2.7 Ga ago, and the resulting terrain is taken to be the basement, at least for the Contendas-Mirante sequence. The relationships to the Brumado and Umburanas metamorphic complexes are not clear, and these sequences may be of Archaean age. The Contendas-Mirante sequence was affected by strong lower Proterozoic deformation (~ 2 Ga ago) and contemporaneous granitic intrusions (like the Gameleira granite). Large, domal structures, interpreted as mantled gneiss domes, such as those associated with the Boa Vista and Sete Voltas granitoid rocks, also formed at this time. A late Proterozoic to Early Palaeozoic thermal event affected the southwestern part of the region at-0.5-0.7 Ga ago as revealed by mica K-Ar ages.
Geologia USP. Série Científica, 2018
O Cinturão Salvador-Esplanada-Boquim (CSEB) é provavelmente um ramo nordeste do Orógeno Itabuna-S... more O Cinturão Salvador-Esplanada-Boquim (CSEB) é provavelmente um ramo nordeste do Orógeno Itabuna-Salvador-Curaçá. Neste trabalho, inédito para a região, é apresentada a caracterização petrográfica, petroquímica e geocronológica preliminar das rochas granulíticas da porção central-norte desse cinturão, onde foram separadas quatro unidades granulíticas ácidas e intermediárias, além de bandas de granulitos máficos, granulitos aluminosos e quartzitos. As quatro unidades ácidas e intermediárias são ortogranulitos foliados onde os granulitos máficos encontram-se encaixados sob a forma de lentes. Essas rochas foram atravessadas por diques orosirianos, dacíticos-riolíticos (Diques de Arauá). O estudo litogeoquímico dos granulitos ácidos e intermediários revelou quatro séries cálcio-alcalinas de baixo a alto K, assim denominadas: enderbítica (Ed1), enderbítica (Ed2); charnockítica de composição monzogranítica (MCh) e charnoenderbítica (Ch-Ed). Diagramas multielementares indicam que as quatro ...
Proceedings of the 3 Simpósio Brasileiro de Geofísica, 2008
Revista Brasileira de Geociências, 2003
GEOLOGY OF THE SOUTHERN SEGMENT OF THE ITABUNA-SALVADOR-CURAÇÁ OROGEN AND FIELD-TRIP GUIDE Geolog... more GEOLOGY OF THE SOUTHERN SEGMENT OF THE ITABUNA-SALVADOR-CURAÇÁ OROGEN AND FIELD-TRIP GUIDE Geological mapping, petrographic, petrochemical, tectonic, geochronological and isotopic studies that have been carried out on the poly-deformed Archean terranes of southern Bahia have discriminated different domains. To the western part (Jequié Block) there occur heterogeneous granulites, from igneous and metasedimentary origin (3.2-2.9Ga) besides enderbitic, charnoenderbitic and charnockitic rock units (2.8-2.7Ga), all of them exihibiting calc-alkaline chemical affinities, with high to intermediary potash contents. To the eastern part (Itabuna-Salvador-Curaçá Block), most of the rock units cropping out are metatonalites-metatrondhjemites (2.6-2.5Ga) and metamonzonites (2.4Ga), the first ones presenting calc-alkaline affinities with low potash and the last ones tending to a shonshonitic character. Both types display enclaves of gabbros and granulitized supracrustal rocks. Between the above mentioned blocks there is occurring a narrow belt of quartz-feldspatic rocks, besides some granites ("Band" of Ipiaú), all of them under the amphibolite facies of metamorphism. About 2.0-1.9Ga the collision of the two above-mentioned blocks have occurred. Such collision was responsible for the tectonic superposition of blocks and also for the granulitization processes of the southern part of the Itabuna-Salvador-Curaçá Block. Nevertheless, the "Band" of Ipiaú, positioned between the two blocks remained preserved in the amphibolite facies. During the peak of the metamorphism were generated leucocharnockites, garnet-cordierite bearing types, that have usually been considered of anatetic origin (metasediment derived) as well as charnockites formed by partial melting of the enclosing rocks, these latter usually exihibint very typical oval structures
Geologia USP. Série Científica, 2018
O Domo de Itabaiana encontra-se inserido no Domínio Vaza Barris da Faixa de Dobramentos Sergipana... more O Domo de Itabaiana encontra-se inserido no Domínio Vaza Barris da Faixa de Dobramentos Sergipana, no Estado de Sergipe. Está representado por um complexo gnáissico-migmatítico, constituído por ortognaisses migmatizados, com intercalações de níveis anfibolíticos. O conjunto foi retrabalhado e soerguido durante o processo de deformação Neoproterozoica dessa faixa. Estudos petrográficos revelam que os ortognaisses são de composição tonalítica a granodiorítica, por vezes com feições desde protomiloníticas a miloníticas. A litogeoquímica evidenciou um caráter sódico nessas rochas, as quais foram analisadas em dois grupos distintos, em relação aos seus padrões em ETR e teores de K2O. Os litotipos com teores de K2O < 2,5% compreendem termos da série cálcio-alcalina de baixo K a cálcio-alcalina normal, enquanto aqueles com teores de K2O ≥ 2,5% compreendem termos posicionados na interface da série cálcio-alcalina normal com a série cálcio-alcalina de alto K. Os dois grupos possuem anomal...
Revista Brasileira de Geociências, 2003
THE SÃO FRANCISCO CRATON IN THE STATE OF BAHIA: A SYNTHESIS During the end of the Paleoproterozoi... more THE SÃO FRANCISCO CRATON IN THE STATE OF BAHIA: A SYNTHESIS During the end of the Paleoproterozoic, collisions of crustal segments took place in the São Francisco Craton. Such collisions juxtaposed Archean rock units (e.g. Gavião Block and their ancient TTG nucleous, metasedimentary sequences of Contendas Mirante, Umburanas and Mundo Novo, Jequié and Mairi Complexes, Serrinha Nucleous, etc...) and younger units formed during the early Paleoproterozoic (e.g. Jocobina Group, Rio Itapicuru and Capím Greenstone Belts, etc...). The associated metamorphism re-equilibrated these units under granulite, amphibolite and greenshcist facies forming linear poli-deformed mobile belts like those of Itabuna and Salvador-Curaçá. During the Mesoproterozoic, this complex metamorphic basement underwent N-S rifting and deposition of the sedimentary piles of the Espinhaço Supergroup, which overlaped their original margins and formed flat-lying cover rocks. Covering these rocks and part of the Archean and Paleoproterozoic basement, the plataformal sequences (glacial and pelitic-carbonatic) of the São Francisco Supergroup took place during the Late Neoproterozoic. Only at the end of the Neoproterozoic, the present outline of the São Francisco Craton was accomplished by a ring of collisional orogens that circumscribe its foreland. These rings are composed by Brasiliano fold belts, as the Sergipano (to the northeast), Riacho do Pontal-Rio Preto (to the north), Brasília-Rio Grande (to the west and south) and Araçuaí (to the east). During the Paleozoic, important stable shelf sequences were deposited and almost covered the craton and its surrounding terranes. During late Jurassic and early Cretaceous a new rift formed (Reconcavo-Tucano), as a result of the Pangea breakup.
Http Www Theses Fr, 1991
La partie centre sud-est du craton de sao francisco comporte d'e en w trois domaines: le bloc... more La partie centre sud-est du craton de sao francisco comporte d'e en w trois domaines: le bloc archeen de jequie, la ceinture volcano-sedimentaire de contendas-mirante et le bloc archeen du gaviao. On reconnait un socle commun fait de granitoides du type ttg dates a 3,35-3,45 ga, et qui constitue le plus ancien noyau crustal connu au bresil. La bordure w du bloc de jequie, formee d'un batholite charnockitique a tendance alcaline et de roches supracrustales plus anciennes a subi un metamorphisme granulitique (p-t:6-7 kb, 750-850c) date a 2,7 ga. Cet ensemble a ete retromorphose a 2,0 ga. La ceinture volcano-sedimentaire de contendas-mirante comprend: le socle ttg, la formation de jurema-travessao 3,0 a 3,3 ga (volcanites tholeiitiques a affinite continentale, formations ferriferes rubanees, marbres et grauwackes; les metapelites des formations de rio gaviao et mirante (2,5 ga) avec des intercalations de volcanites calco-alcalines a affinite d'arc continental; les meta-arkoses de la formation d'areiao (2,15 ga). Les granites peralumineux (1,9 ga) sont les episodes magmatiques les plus tardifs. Le metamorphisme regional de ht/bp est prograde d'w en e. On observe la succession des zones a chlorite, biotite, cordierite, andalousite (p:2,9-3,2 kb, t:500-580c), sillimanite-muscovite (t:590-630c), et sillimanite-feldspath potassique (p:3,5-4 kb, t:655-660c). La bordure orientale du bloc du gaviao est representee par les granitoides illes de lagoa do morro et de la serra dos pombos, dates respectivement de 3,2 et 2,8 ga. La decroissance marquee du taux d'accretion crustale semble constituer le changement le plus net dans l'evolution de la croute de cette portion sud-est du craton de sao francisco, lors de la transition archeen-proterozoique. En revanche, ce processus est dominant au cours de l'archeen pour les grandes unites lithologiques. Des la transition archeen-proterozoique, le recyclage crustal devient ainsi le processus principal, la genese par fusion crustale pure des granites transamazoniens en etant l'illustration la plus claire. Ceci contraste avec l'evolution de la chaine birriminenne a 2,1 ga de l'afrique de l'ouest, ou le recyclage crustal a joue un role minime
Boletim IG-USP. Publicação Especial, 1995
O Maciço Nefelina-Sienítico Itarantim (220 km2) constitui uma intrusão brasiliana (idade Rb-Sr de... more O Maciço Nefelina-Sienítico Itarantim (220 km2) constitui uma intrusão brasiliana (idade Rb-Sr de 727 ± 30 Ma) localizada no extremo sul do alinhamento de rochas alcalinas existente no sul do Estado da Bahia. Ele é constituído essencialmente por nefelinasienitos com biotita ou egirina e por diques alcalinos, mais abundantes no biotita-nefelina-sienito. Estes diques constituem as rochas mais evoluídas deste maciço. Recentemente foi identificado um dique de sodalita-sienito de cor azul encaixado no biotita-nefelinasienito, localizado na região sudoeste do maciço e que está sendo explorado como rocha ornamental. Este dique, portador de sodalita magmática e cuja idade de cristalização está compreendida entre 720 ± 9 Ma e 732 ± 24 Ma (Pb-PbZr), trunca a foliação magmática do sienito encaixante e provoca formação de sodalita metassomática. Os dados petrográficos indicam que a sodalita magmática do dique forma-se no final da cristalização (500-600oC) de um magma particularmente rico em flu...
During the geological mapping of the Salvador city the conglomerates outcropping at Mont Serrat w... more During the geological mapping of the Salvador city the conglomerates outcropping at Mont Serrat were studied. This outcrop is located near the escarpment of the Salvador fault, which marks the boundary between the Salvador high and the Recôncavo basin. These conglomerates belong to the Salvador formation, and they provide useful information concerning the major rock types at the source áreas and the deposicional environments. The Salvador high is comprised of ortho and para-derived rocks intensely deformed and metamorphosed in the granulite and amphibolite facies, together with mafic dikes and sienogranites emplaced in a more recent time. The sedimentary structures and channel geometry indicate the action of a variety of depositional and transport processes including traction, grain flows and debris flows. Sediments accumulated in fan deltas prograding into the tectonic lake of the Recôncavo basin from the Salvador fault. The dominant sediment transport direction was towards southwe...
The Floresta Azul Alkaline Complex is one of the intrusions from the Alkaline Province of the Sou... more The Floresta Azul Alkaline Complex is one of the intrusions from the Alkaline Province of the South Bahia State. Which host the blue coloured biotite-sodalite-syenite ore. The Pb-Pb isotopic results for single zircon from the sodalite-syenites of this complex results an age of 696 ± 3 Ma, which is interpreted as the minimum formation age for the blue-sodalite-ore.O Complexo Alcalino Floresta Azul constitui uma das intrusões da Província Alcalina do Sul do Estado da Bahia quehospeda mineralização de sodalita-sienito de cor azul. Os resultados isotópicos Pb-Pb em zircão obtidos em um biotita-sodalitasienito deste complexo forneceram uma idade de 696 ± 3 Ma que é interpretada como a idade mínima da formação da mineralização em sodalita azul
A idade mínima de cristalização de 2095 ± 5 Ma (Pb-Pb zircão) obtida para o Batólito Sienítico de... more A idade mínima de cristalização de 2095 ± 5 Ma (Pb-Pb zircão) obtida para o Batólito Sienítico de Itiúba, que não apresenta ortopiroxênio em sua mineralogia, é incongruente com as idades existentes para o clímax do metamorfismo granulítico (2050–2080 Ma) no Cinturão Móvel Salvador-Curaçá. A hipótese levantada para explicar estes dados advoga que a tectônica transamazônica neste cinturão seja a responsável pela colocação lado a lado de segmentos catazonais e mesozonais da crosta arqueano-paleoproterozóica.The minimal crystallization age of the 2095 ± 5 Ma (Pb-Pb zircon) obtained to the Itiúba Syenitic Batholith, which to do not have ortopyroxene in your mineralogy, is incongruent with the granulitic metamorphism climax (2050–2080 Ma) in the Salvador-Curaçá mobile belt. The hypothesis to support this data suggest that in this belt the trasamazonian tectonic was responsible to the emplacement of catazone and mesozone segments from the archean-paeleproterozoic crust
The Salvador-Esplanada-Boquim Belt (SEBB) is considered a branch of the São Francisco Craton, loc... more The Salvador-Esplanada-Boquim Belt (SEBB) is considered a branch of the São Francisco Craton, located in its northeastern portion, in the Brazilian states of Bahia and Sergipe. This paper analyzed the U-Pb (LA-ICP-MS) geochronology on the Gneissic-Migmatitic Complex (GMC) zircons in the rocks of the SEBB. Six analyses were made on the rocks of GMC and two on granitic dykes. The obtained data allowed concluding that the GMC rocks were formed between 2150 ± 19-2188 ± 30 Ma, while the dykes had their crystallization in line with the process of regional metamorphism in 2073 Ma. These metamorphic evens are interpreted as products of the collision with the Serrinha
Geologia USP. Série Científica, 2021
O Cinturão Salvador-Esplanada-Boquim se localiza na porção nordeste do Cráton do São Francisco, n... more O Cinturão Salvador-Esplanada-Boquim se localiza na porção nordeste do Cráton do São Francisco, nos estados da Bahia e do Sergipe, apresentando duas faixas litológicas de rochas metamórficas, denominadas Complexo Gnáissico-Migmatítico e Complexo Granulítico Esplanada-Boquim. O presente trabalho abrange os estudos de campo, petrográficos e litoquímicos do Complexo Gnáissico-Migmatítico, porção norte do Cinturão Salvador-Esplanada-Boquim. Ocorrem rochas metamórficas de médio grau, de composição granítica a granodiorítica e, subordinadamente, tonalítica, sendo comuns as evidências de processos de migmatização, principalmente na sua porção ocidental. Com base nos estudos de litoquímica, as rochas foram subdivididas em rochas sódicas, potássicas e intermediárias e caráter peraluminoso a metaluminoso. Análises dos elementos-traço, terras raras e as razões Eu/Eu* sugerem a atuação de processos metamórficos e de contaminação crustal a partir de fonte de natureza calcioalcalina. Ainda a part...
Revista de Geociências do Nordeste, 2020
4Doutor em Geologia, Programa de Pós-Graduação em Geologia, Núcleo de Geologia Básica (NGB), ... more 4Doutor em Geologia, Programa de Pós-Graduação em Geologia, Núcleo de Geologia Básica (NGB), Instituto de Geociências, Universidade Federal da Bahia (UFBA), Salvador-BA, Brasil. ORCID: https://orcid.org/0000-0002-2143-5594 Email: mmm@ufba.br Resumo A área de estudo localiza-se na porção extremo norte do Cinturão Salvador-Esplanada-Boquim, nas porções sul do estado de Sergipe e nordeste do estado da Bahia, Brasil. Este Cinturão apresenta três faixas litológicas de rochas metamórficas denominadas Complexo Migmatítico Rio Real-Riachão do Dantas (CMRR), Complexo Granulítico Esplanada-Boquim (CGEB) e Complexo Gnáissico/Migmatítico-Granulítico Costa Atlântica (CGGCA). Esse artigo se restringe aos estudos petrológicos da primeira faixa de migmatitos que foi subdividida em Ortognaisse Migmatítico Granítico Leste (OMGL) e Ortognaisse Migmatítico Granítico Oeste (OMGO). Ambas, macroscopicamente e petrograficamente são similares, cujas paragêneses minerais indicam a ocorrência de process...
Brazilian Journal of Geology, 2020
In the southern portion of the Borborema Province, in the Sergipano Orogenic System, three baseme... more In the southern portion of the Borborema Province, in the Sergipano Orogenic System, three basement inliers have been described: the Domes of Itabaiana and Simão Dias, in Sergipe; and the Girau do Ponciano Dome, in Alagoas. The Itabaiana and Simão Dias Domes occur in the central part of the Vaza Barris Domain, being composed of gneisses and migmatites. The Itabaiana rocks are calc-alkaline with trondhjemitic affinities. The Girau do Ponciano Dome, outcropping in the Macururé Domain, consists mainly of tonalitic, dioritic, monzonitic, granodioritic and highgrade granitic orthogneisses. SHRIMP U-Pb zircon date of a melanosome sample from a trondhjemitic migmatitic gneiss in the central part of Itabaiana Dome provided an age of 2831 ± 6 Ma, indicating that the migmatitic gneisses of this dome are correlated to the Mesoarchean terranes of the São Francisco Craton (Serrinha Block). These rocks represent the oldest geological record in the Sergipe State.
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Papers by Moacyr Moura Marinho