Marly Babinski

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Papers by Marly Babinski

Geologia e a descoberta da magnitude do tempo

Chapter 45 Glacially influenced sedimentation of the Puga Formation, Cuiabá Group and Jacadigo Group, and associated carbonates of the Araras and Corumbá groups, Paraguay Belt, Brazil

Geological Society, London, Memoirs, 2011

Discontinuous exposures of diamictite (>1000 km) termed the Puga Formation (Fm.) and interpret... more Discontinuous exposures of diamictite (>1000 km) termed the Puga Formation (Fm.) and interpreted as being related to a late Cryogenian glacial event are known in the Paraguay Belt (Brazilian–Pan-African Orogeny) and part of the Amazon craton and Rio Apa Block. These diamictite units and a mixed assemblage of sandstone, conglomerate and claystone were first named the Jangada Group. Recent interpretations have shown that the diamictite of the Puga Formation passes laterally into metasediments of the Cuiabá Group, interpreted as glacially influenced turbidites. The correlative Jacadigo Group in the southern Paraguay Belt includes a thick succession of banded iron formation (BIF) bearing large boulders that have been interpreted as recording glacially influenced sedimentation. The diamictite of the Puga Fm. is overlain by two different carbonate-bearing successions, the Corumbá Group (Cadieus, Cerradinho, Bocaina, Tamengo and Guaicurus formations) in the south and the Araras Group (M...

Aplicação de isótopos de Pb, Sr, H e O como traçadores da recarga e da contaminação de aqüíferos metropolitanos: um exemplo da Bacia do Alto Tietê: um exemplo da Bacia do Alto Tietê

Muitas foram as pessoas e Instituições que direta ou indiretamente, por muito ou por pouco tempo,... more Muitas foram as pessoas e Instituições que direta ou indiretamente, por muito ou por pouco tempo, colaboraram com a realização deste trabalho. Todos foram fundamentais! Agradeço muito à minha orientadora, Profa. Dra. Marly Babinski, que me deu a oportunidade de trilhar um novo e maravilhoso caminho, com esse projeto, e me ensinou muito mais do que ciência. Sua dedicação e cuidado com a pesquisa são e sempre serão um exemplo para mim. Com a mesma intensidade gostaria de agradecer ao Prof. Dr. Ricardo Hirata, co-orientador desta tese e idealizador do projeto-pai desta pesquisa (recarga na BAT). Foi imensamente importante para a minha formação como pesquisadora e como pessoa as discussões e observações levantadas durante todo o trabalho. Considero um privilégio ter tido os dois como orientadores, podendo desfrutar da experiência e sabedoria que possuem, com a permissão, por ser aluna, de realmente dar trabalho. A execução desta tese não seria possível sem os fomentos fornecidos pela Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP), através do auxílio à pesquisa n o 02/07202-3 e da bolsa de estudos (processo n o 04/05360-6). Ao Instituto de Geociências e ao Centro de Pesquisas Geocronológicas (CPGeo) da USP devo o apoio institucional, fundamental para a tranqüila decorrência da pesquisa. Agradeço também a colaboração da Profa. Dra. Maria do Rosário Zucchi, do

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Who to blame for groundwater fluoride anomaly in São Paulo, Brazil? Hydrogeochemistry and isotopic evidence

Applied Geochemistry, 2018

Fluoride concentrations up to 10 mg.L-1 have been described in the groundwater of the biggest Sou... more Fluoride concentrations up to 10 mg.L-1 have been described in the groundwater of the biggest South American City, São Paulo, Brazil. Possible suspects were minerals in crystalline or sedimentary rocks, or industrial activities. Hydrochemistry tools pointed that the fluoride occurrence has positive correlation with Na and HCO 3 concentrations and negative correlation with Ca 2+. The saturation index are negative for fluorite in all samples, but samples with high fluoride content have calcite saturation index close to zero, indicating the precipitation of calcite maybe a mechanism that is taking out the Ca +2 and enhancing fluorite dissolution. Samples with fluoride concentrations >1.5 mg.L-1 are related to samples more depleted in H and O heavier isotopes and deeper groundwater flow with higher temperature. This anomaly is probably associated with fluorite dissolution, present in a fault system with an ancient hydrothermal activity, with deep circulation of groundwater flows in the crystalline basement rocks.

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Anthropogenic Zn contamination dispersion in Sepetiba Bay evidenced by Zn isotopes

Geochimica Brasiliensis

Sedimentary processes in coastal environments play a key role in the spatial dispersion of metal ... more Sedimentary processes in coastal environments play a key role in the spatial dispersion of metal contaminants, including Zn. Combining Zn stable isotope signatures (δ66Zn) with traditional proxies of sedimentary sources and dispersal and post-depositional processes is a promising approach to understanding Zn anthropogenic dynamics in coastal systems that remains untested. To this end, we coupled geochemical and isotope tools to infer sedimentary contributions on Zn fate and behavior in surface sediments of Sepetiba bay, a tropical lagoon in Rio de Janeiro state chronically contaminated by an old stake of electroplating wastes Zn-enrich. Our results show high variability in δ66Zn values (0.43‰ to 0.89‰) and Zn enrichment factors (1 to 23-fold), evidencing a gradient in mixing sedimentary sources. The biplot δ66Zn versus 1/[Zn] highlights that the Zn isotope variability of most samples fell within a mixing source trend involving natural Zn (+0.29‰, 67 mg.kg-1) and anthropogenic Zn (+0...

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U-Pb SHRIMP geochronology and isotope chemostratigraphy (C, O, Sr) of the Tamengo Formation, southern Paraguay Belt, Brazil

The Gorutuba Formation: coastal to continental sedimentation on the eastern margin of Bambuí Basin (MG)

Propõe-se neste trabalho a formalização da Formação Gorutuba, unidade que engloba os únicos regis... more Propõe-se neste trabalho a formalização da Formação Gorutuba, unidade que engloba os únicos registros remanescentes de ambientes litorâneos e continentais da margem leste da Bacia Bambuí, desenvolvida durante a Orogênese Brasiliana. As rochas da Formação Gorutuba são reconhecíveis em três áreas principais. Nas serras da Jaíba e Colonial, a unidade apresenta um pacote basal de brecha composta por clastos de calcário imersos em matriz arcoseana, que indicam o retrabalhamento do calcário da Formação Jaíba, subjacente. Arcósio ocorre na forma de lentes e camadas intercaladas na brecha, tornando-se predominante em direção ao topo da unidade, onde ocorrem corpos isolados de ortoconglomerado. Na Serra do Gorutuba, a unidade apresenta o mesmo arranjo estratigráfico, porém assenta-se diretamente sobre siltito da Formação Serra da Saudade. No Sinclinal de Buenópolis, por sua vez, arenitos arcoseanos com estratificações cruzadas acanaladas e eventuais lentes de conglomerado e pelito assentam-s...

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The São Francisco Palaeocontinent

Tracing final Gondwana assembly: Age and provenance of key stratigraphic units in the southern Paraguay Belt, Brazil

Precambrian Research, 2018

The Paraguay Belt in central South America developed in response to the collision between the Ama... more The Paraguay Belt in central South America developed in response to the collision between the Amazonian Craton, the Rio Apa Block, the São Francisco Craton and the Paranapanema Block and marks the final suture of western Gondwana. The traditional 'Brasiliano' age (~620 Ma) of this belt has recently been questioned by evaluation of the geological record of sedimentation, deformation, metamorphism and magmatism, which indicate the closing stages of orogenesis occurred well into the Cambrian. Here we investigate the time of deposition and source areas for the metasedimentary rocks of the Jacadigo and Corumbá Groups overlying the Amazonian and Rio Apa cratons in the southern part of the Paraguay belt. 1177 LA-ICPMS and 61 SHRIMP detrital zircon U-Pb ages were analysed from samples taken from both the basement and the sedimentary succession. A new maximum age constraint of 686 ± 10 Ma is presented for the Puga Formation to complement existing work in the region. The youngest ages from our samples are 566 ± 8 Ma and 543 ± 11 Ma. These maximum depositional ages indicate that final sedimentation began no earlier than 543 ± 11 Ma in the southern Paraguay Belt. Given that zircon inheritance in these rocks continues up until this age and that known Amazonian Craton ages are older than ~950 Ma we discuss other potential sources for these sediments by integrating the U-Pb detrital zircon data with Hf isotopic data. Cumulative proportion analysis of our detrital U-Pb data set indicate a transition from a passive to a collisional setting. Our final conclusions are that sedimentation in the belt transitioned from a passive margin environment to a collisional setting, consistent with an ocean to the east of the present-day Amazonian Craton that did not close until the Cambrian.

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Xistos Verdes Do Alto Araçuí, Minas Gerais: Vulcanismo Básico Do Rifte Neoproterozóico Macaúbas

Revista Brasileira de Geociências, 2005

INTRODUÇÃO Na bacia do alto Rio Araçuaí, municípios de São Gonçalo do Rio Preto e Senador Modesti... more INTRODUÇÃO Na bacia do alto Rio Araçuaí, municípios de São Gonçalo do Rio Preto e Senador Modestino Gonçalves, aproximadamente 60 km a nordeste de Diamantina (MG), aflora um pacote de xistos verdes, cujo posicionamento estratigráfico, significado tectônico e idade eram muito controversos na literatura (Fig. 1). É fato, entretanto, que estes xistos verdes têm protólitos vulcânicos básicos, acumulados em ambiente sub-aquático (Bettega & Rocha 1986, Uhlein 1991, Souza & Grossi Sad 1997). Na busca de melhor entendimento do papel destas rochas básicas na evolução da Faixa Araçuaí realizou-se estudos detalhados sobre a geologia estrutural, estratigrafia, geoquímica e geocronologia dos xistos verdes do Alto Araçuaí. No presente trabalho demonstra-se que os xistos verdes do Alto Araçuaí representam derrames basálticos e rochas vulcanoclásticas proximais, associados ao desenvolvimento da bacia rifte na qual se acumularam sedimentos glaciogênicos do Grupo Macaúbas. OS XISTOS VERDES NO CENÁRIO DA FAIXA ARAÇUAÍ A Faixa Araçuaí, segundo a definição original de Almeida (1977), é um cinturão de dobramentos brasiliano que, nos estados de Mi

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Diamictitic iron formation (DIF) deposits of the Neoproterozoic Nova Aurora Iron District (Macaúbas Group, Southeast Brazil)

Journal of South American Earth Sciences, 2021

A Formação Gorutuba: sedimentação litorânea a continental na margem leste da Bacia Bambuí (MG)

Geologia USP. Série Científica, 2016

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Chemostratigraphy of the lower Bambuí Group, southwestern São Francisco Craton, Brazil: insights on Gondwana paleoenvironments

Brazilian Journal of Geology, 2016

ABSTRACT: The Bambuí Group, the most extensive carbonate-siliciclastic cover on the São Francisco... more ABSTRACT: The Bambuí Group, the most extensive carbonate-siliciclastic cover on the São Francisco craton, has been a matter of debate because of its potential correlations to global glacial events. Unfortunately, most available chemostratigraphic data came from samples collected on surface rock exposures, ever susceptible to the aggressive chemical weathering that characterizes the southeastern Brazil. On the other hand, we present here high-resolution chemostratigraphic studies based on C, O and Sr isotopic data from 53 samples collected along a weathering-free, continuous, 175 m thick sedimentary succession. This succession was recovered by borehole drilling in the southwestern São Francisco craton, where occur the Carrancas and Sete Lagoas formations, the lowermost units of the Bambuí Group. The drill cores reveal extremely irregular contacts between the basal diamictite and its basement, an Archaean foliated granodiorite. Geochronological and sedimentological data strongly sugge...

Magmatismo e Tectônica Do Orógeno Araçuaí No Extremo Leste De Minas e Norte Do Espirito Santo (18°-19°S, 41°-40°30’W)1

Geonomos, 2013

This paper focuses on magmatic episodes and their relations to the main regional deformation in t... more This paper focuses on magmatic episodes and their relations to the main regional deformation in thebackarc region of the Araçuaí Orogen (southeastern Brazil). The main tectonic event took placeduring the syncollisional stage (ca. 585-560 Ma) and imprinted the regional, solid-state foliation (Sn)in most rocks of this orogen. In the mapped region (18°-19°S, 41°-40°30’W), the older unit (NovaVenécia Complex) occurs in small areas and consists of migmatitic, sillimanite-garnet-cordieritebiotiteparagneisses with minor calcsilicate intercalations. The widespread garnet-biotite granites(Carlos Chagas, Montanha and Ataléia suites) are correlated to the syncollisional, S-type, G2 supersuite(ca. 585-560 Ma) of the Araçuaí Orogen, because they persistently record Sn, usually associated tostriking mylonitic features. However, we also correlate some massifs of undeformed garnet-biotitegranite to the Carlos Chagas Suite. Outwards from such undeformed pods, this Sn-free, garnet-biotitegranite prog...

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Orógeno Araçuaí: Síntese Do Conhecimento 30 Anos Após Almeida 1977

Geonomos, 2013

The Araçuaí Fold Belt was defined as the southeastern limit of the São Francisco Craton in the cl... more The Araçuaí Fold Belt was defined as the southeastern limit of the São Francisco Craton in the classicalpaper published by Fernando Flávio Marques de Almeida in 1977. This keystone of the Brazilian geologicliterature catalyzed important discoveries, such as of Neoproterozoic ophiolites and a calc-alkaline magmaticarc, related to the Araçuaí Belt and paleotectonic correlations with its counterpart located in Africa (the WestCongo Belt), that provided solid basis to define the Araçuaí-West-Congo Orogen by the end of the 1990thdecade. After the opening of the Atlantic Ocean in Cretaceous times, two thirds of the Araçuaí-West-CongoOrogen remained in the Brazil side, including records of the continental rift and passive margin phases ofthe precursor basin, all ophiolite slivers and the whole orogenic magmatism formed from the pre-collisionalto post-collisional stages. Thus, the name Araçuaí Orogen has been applied to the Neoproterozoic-Cambrianorogenic region that extends from the southe...

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Are varangian or sturtian the glacial deposits on the São Francisco craton? Evidence from determination of sedimentary rocks and minerals of the Neoproterozoic Una Group

Age determination and age related provenance analysis of the Proterozoic glaciation event in central eastern Brazil

A large epeiric methanogenic Bambuí sea in the core of Gondwana supercontinent?

Geoscience Frontiers, 2020

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.

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Highly 13C-enriched carbonate and organic matter in the Neoproterozoic sediments of the BambuíGroup, Brazil

by Marly Babinski and Farid Chemale Jr.

Precambrian Research, 1995

Paleontological and radiometric dating methods (RbSr, KAr and PbPb) suggest Neoproterozoic ages f... more Paleontological and radiometric dating methods (RbSr, KAr and PbPb) suggest Neoproterozoic ages for sedimentary carbonate rocks of the BambuíGroup in the southern part of the Sa˜o Francisco Basin of central Brazil. The δ13C values for carbonates fall within two ranges, − 2 to + 2‰ and + 10 to + 16‰. For both groups coexisting organic carbon is depleted in

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Paleomagnetism and geochronology of the Bebedouro cap carbonate: evidence for continental-scale Cambrian remagnetization in the São Francisco craton, Brazil

by Marly Babinski and M. D'Agrella-Filho

Precambrian Research, 2004

New Pb-Pb ages, rock magnetic, and paleomagnetic data were obtained on Neoproterozoic carbonates ... more New Pb-Pb ages, rock magnetic, and paleomagnetic data were obtained on Neoproterozoic carbonates of the Salitre Formation which conformably overlie the glacial rocks of the Bebedouro Formation in undeformed areas of the Irecê basin, São Francisco craton. These data give new supporting evidence for a large-scale remagnetization and resetting of the U-Pb isotopic system at Cambrian times along the São Francisco and Irecê basins, which cover more than 300,000 km 2 of the São Francisco craton surface. A 207 Pb-206 Pb isochron age of 514 ± 33 Ma was on undeformed, stromatolitic carbonates from the Salitre Formation. Although samples from other sites give almost non-radiogenic Pb signatures, they fall at the lower end of this line. Rock magnetic properties obtained for most of the sites are typical of remagnetized carbonates, and include: wasp-waisted hysteresis loops, contradictory Lowrie-Fuller and Cisowski tests, and anomalously high hysteresis ratios. Some samples, however, have presented only some of these magnetic characteristics. Four magnetic components (A, B, C, and D) were isolated from the Salitre carbonates. Three of them (A, B, and C) are comparable to previous results from the correlative Bambuí carbonates, which crop out ca. 600 km southward. The component C, carried by fine-grained SD-PSD magnetite, was identified at 23 sites. It directs steeply positive to the northeast, giving a paleomagnetic pole (SaC) at 33 • N, 323 • E (α 95 = 4.0 • , k = 23.6). The SaC pole overlaps with that obtained from component C of Bambuí carbonates (BaC pole: 30 • N, 321 • E, α 95 = 3.8 • ). The paleopoles from component B of Salitre (SaB) and Bambuí (BaB) also lie close but are statistically different. After rotation of South America to Africa, all these poles fall close to the ∼520 Ma segment of the Gondwana apparent polar wander path, suggesting that the resetting of the isotopic and magnetic systems in the Neoproterozoic carbonates of the São Francisco craton occurred at that time. The single polarity directions found along the whole sedimentary succession in both areas give additional support for rapid remagnetization events. We suggest that paleomagnetic data and most of the Pb-Pb isochron ages in the São Francisco carbonates recorded a regional-scale fluid migration event, in the aftermath of the Brasiliano (Panafrican) collision. This fluid-flow event may also have concurred for the genesis of the Pb-Zn mineralizations found across the basin.

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