%0 Journal Article
%4 sid.inpe.br/plutao/2017/06.21.20.22
%2 sid.inpe.br/plutao/2017/06.21.20.22.03
%@doi 10.1093/gji/ggx261
%@issn 0956-540X
%F lattes: 0842543237562135 3 BolognaEgbPadPádVit:2017:3DInCo
%T 3-D inversion of complex magnetotelluric data from an Archean-Proterozoic terrain in northeastern São Francisco Craton, Brazil
%D 2017
%9 journal article
%A Bologna, Mauricio S.,
%A Egbert, Gary D.,
%A Padilha, Antonio Lopes,
%A Pádua, Marcelo Banik de,
%A Vitorello, Ícaro,
%@affiliation Universidade de São Paulo (USP)
%@affiliation Oregon State University
%@affiliation Instituto Nacional de Pesquisas Espaciais (INPE)
%@affiliation Instituto Nacional de Pesquisas Espaciais (INPE)
%@affiliation Instituto Nacional de Pesquisas Espaciais (INPE)
%@electronicmailaddress mbologna@usp.br
%@electronicmailaddress
%@electronicmailaddress antonio.padilha@inpe.br
%@electronicmailaddress marcelo.banik@inpe.br
%B Geophysical Journal International
%V 210
%P 1545-1559
%K Indução Eletromagnética Terrestre, Inversão 3-D, Cráton do São Francisco, Bloco Serrinha.
%X We present a magnetotelluric (MT) study in the northeastern part of the São Francisco Craton that encompasses an Archean-Proterozoic terrain, the Serrinha Block, breached by a rift basin developed mostly in Early Cretaceous times during the opening of the South Atlantic Ocean. Even though the MT sites are regularly spaced, the profiles have different orientations from one another, making the data distribution over the area highly uneven and therefore non-ideal for 3-D modeling. However, the data set is very complex, with dimensionality analysis indicating prevalence of 3-D geoelectric structure. Results from 3-D inversion are evaluated for robustness and potentiality for yielding tectonic information. At upper crustal depths, the resulting 3-D model is coherent with surface geology, whereas at mid and lower crustal depths more cryptic structures are revealed, likely of Palaeoproterozoic age. The most striking features in the model are several strong (∼1 Ω⋅m) crustal conductors beneath the central part of the Serrinha Block, which we attribute to a Palaeoproterozoic oceanic plate subduction and arc-continent collision event involving the Rio Itapicuru Greenstone Belt and the basement of the Serrinha Block. The west-dipping geometry of these conductors provides a constraint on subduction polarity and gives support to tectonic evolutionary models proposing that the Rio Itapicuru Belt was formed in an island arc environment.
%@language en
%3 bologna_3d.pdf
%O Setores de Atividade: Pesquisa e desenvolvimento científico.