Geochronology of mafic magmatism and hydrothermal alteration during early stages of South Atlantic opening

Carvas, Karine Zuccolan; Vasconcelos, Paulo; Marques, Leila Soares; Ubide, Teresa; Carmo, Isabela de Oliveira; Babinski, Marly

doi:10.1016/j.gca.2021.08.017

Cited by 9 publications

(55 citation statements)

References 60 publications

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“…Sr, Nd and Pb isotope compositions of five low-Ti (Ribeira) dykes were measured by TIMS at the Centre of Geochronology and Isotope Geochemistry Research, USP. Sr and Nd measurements followed procedures described by Carvas et al (2021). For Pb, sample aliquots were loaded in HBr media through columns filled with Biorad AG 1-X8 anion resin; Pb was eluted with 6.0 M HCl.…”

Section: Isotopic Analysesmentioning

confidence: 99%

“…(Almeida et al, 1986;Piccirillo & Melfi, 1988;Corval et al, 2008). 40 Ar/ 39 Ar ages for whole-rock fragments and plagioclase crystals reveal intrusive ages of ~134 to 130 Ma, but step-heating spectra show a much wider range of apparent ages (~155 to ~55 Ma) due to excess argon and/or alteration (Gomes & Vasconcelos, 2021;Carvas et al, 2021; and references therein).…”

Section: Introductionmentioning

confidence: 99%

“…3.1A) (Almeida, 1986;Piccirillo & Melfi, 1988;Corval et al, 2008). At the Cabo Frio Tectonic Domain, 40 Ar/ 39 Ar geochronology of magmatic amphibolebiotite aggregates indicates a minimum intrusive age of 132.83 ± 0.30 Ma for mafic dykes with MORB-like compositions (Carvas et al, 2021), coeval with the latest stages of Paraná-Etendeka volcanism (Gomes & Vasconcelos, 2021) and with the onset of seafloor production in the southern South Atlantic (Torsvik et al, 2009). A spatially related and chemically distinct group of mafic dykes, compositionally similar to low-Ti basalts from the northern part of the Paraná-Etendeka province (Ribeira) (Bennio et al, 2003;Schmitt et al, 2016;Savastano et al, 2017), occurs along the same fault systems.…”

Section: Introductionmentioning

confidence: 99%

“…(defined by Bennio et al, 2003). B -Primitive mantle normalized (McDonough and Sun, 1995) multi-element patterns of group A…………………………………………………………….35 Albian seawater (Veizer, 1989), CFTD alkaline dykes (Thompson et al, 1998), Campos Basin evaporites (Farias et al, 2019;Lima et al, 2020) and regional continental crust (Peixoto et al, 2017) Cretaceous South Atlantic opening (Piccirillo and Melfi, 1988;Machado et al, 2015;Carvas et al, 2021), exhibiting Serra do Mar Dyke Swarm (SMDS) and Cabo Frio Tectonic Domain (Putirka, 2008;Neave & Putirka, 2017) Continental rifting is a fundamental step in the evolution of divergent plate margins (e.g., Peron-Pivindic et al, 2019;and references therein). Despite extensive studies and numerous models of the evolution of divergent tectonic margins (e.g., McKenzie, 1978;Wernicke, 1985), significant questions remain on the rheological regimes that dominate in magma-rich versus magma-poor rifts.…”

Section: Introductionmentioning

confidence: 99%

“…F -Dyke LM-DA-203, from Cabo Frio. (Carvas et al, 2021) In order to devise an approach for properly dating mafic dykes by the 40 Ar/ 39 Ar laserheating method, to identify and possibly overcome difficulties associated with alteration and excess argon, and possibly derive useful geological information from the altered dykes, we sampled and analyzed distinct phases from four Serra do Mar dykes, located within the Cabo Frio Tectonic Domain. These dykes are ideal targets because of the presence of both altered and unaltered K-bearing phases, and their previously measured saddle-shaped age spectra (Bennio et al, 2003) and variable ages (Almeida et al, 2021).…”

Section: Introductionmentioning

confidence: 99%

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A record of the transition between Gondwana and South Atlantic crust in the tholeiitic intrusive magmatism of Cabo Frio Tectonic Domain, Southeast Brazil

Carvas¹

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código de financiamento 001, processo 1425945) pelo financiamento das análises, cursos, auxílios e bolsas referentes a esta pesquisa. I also thank the Argon Geochronology Laboratory of The University of Queensland (UQ-AGES) for all financial support during my research period in Australia.Agradeço profundamente aos meus orientadores pela imensa dedicação e generosidade.À Professora Doutora Leila Marques, pela incansável busca. Ao Professor Doutor Paulo Vasconcelos, pela incansável pergunta.Agradeço aos colaboradores com os quais tive a sorte de contar ao longo deste trajeto. À Professora Doutora Marly Babinski, agradeço o incentivo criterioso desde os meus tempos de graduação. À Doutora Isabela Carmo, agradeço a frequente troca de boas ideias, a confiança, belas fotografias de campo e amostras adicionais. I am also thankful to Professor Teresa Ubide for reawakening my curiosity whenever we worked together, and for all valuable discussions. Agradeço a todo o corpo docente e técnico-administrativo do Instituto de Astronomia, Geofísica e Ciências Atmosféricas da USP (IAG-USP) pela ajuda e prestatividade em diversos momentos. Sou especialmente grata aos Professores Doutores Marcia Ernesto, Naomi Ussami, Marcelo Bianchi, Carlos Mendonça e Ricardo Trindade pela orientação e suporte constantes. Durante o desenvolvimento deste trabalho no Brasil, fui auxiliada por inúmeras pessoas de diferentes laboratórios da Universidade de São Paulo (USP) e da Universidade Estadual Paulista (UNESP). Agradeço ao Mestre (em breve Doutor) Caio Vicentini (IAG-USP), e aoProfessor Doutor Fábio Machado (UFPR) pela ajuda em meu primeiro campo de amostragem, o qual serviria de base para os seguintes. Agradeço à coordenadora técnica do Laboratório de Preparação de amostras e da Litoteca do IAG-USP, Sônia Alonso, pela prestatividade, pela sabedoria generosa e pelos bolos. Sou grata a toda a equipe do Centro de Pesquisas Geocronológicas do Instituto de Geociências da USP (CPGeo -IGc -USP), sobretudo à especialista técnica em química isotópica e espectrometria de massa Liliane Petronilho.

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Section: Isotopic Analysesmentioning

confidence: 99%