Geology and geochemistry of metabasic rocks from aÇungui supergroup, north of quarenta oitava shear zone, south of sÃo paulo state

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dc.contributor.authorVieira, Otávio Augusto Ruiz Paccola [UNESP]
dc.contributor.authorGodoy, Antonio Misson [UNESP]
dc.contributor.authorLuvizotto, George Luiz [UNESP]
dc.contributor.authorZenero, Jonas Menezes [UNESP]
dc.contributor.institutionUniversidade Estadual Paulista (Unesp)
dc.date.accessioned2021-06-25T10:47:54Z
dc.date.available2021-06-25T10:47:54Z
dc.date.issued2020-01-01
dc.description.abstractBasic and ultrabasic ortho-derived rocks are composed of amphibolites, metabasites and metaultrabasites of meso to neoproterozoic age, are located in the southwest of São Paulo State, in Ribeira Belt southern portion and north of Apiaí Terrain. They are inserted in Supergroup Açungui metavolcanicsedimentary rocks, specifically in Água Clara Formation and Itaiacoca Group The main mineral paragenesis consists of ferrotschermakite- ferrohornblende- magnesiohornblende ± oligoclase andesine, representing the progressive regional metamorphism M1 climax, from 611 °C to 621 °C in temperature and 6.5 kbar to 7.3 kbar (± 0, 6) (Mid amphibolite facies); and a mineral paragenesis of actinolite tremolite ± albite, from M3 regional retrometamorphism (low to mid greenschist facies). Compositional geochemical data classify the rocks as gabbro, basanite and picrite, low potassium sub alkaline to alkaline, Fe-tholeitic to Mg-tholeitic, with a slight tendency to komatiitic basalts. Geotectonic data, corroborated by the behavior of trace elements and REEs, indicate three main signatures for amphibolitic groups: Basic tholeitic and komatiitic rocks associated with mid-ocean ridge (MORB), with possible crust interaction in subduction phase; ultrabasic alkaline ocean island rocks (OIA); and island arc tholeiitic basalts. Therefore, magmatism is correlated to the initial stage of opening of the basin or to the beginning of closure, to the initial phase of tholeitic ocean floor nature, associated with ocean island alkaline basalts.en
dc.description.affiliationPrograma de Pós-Graduação em Geociências IGCE UNESP-Univ Estadual Paulista
dc.description.affiliationDepartamento de Petrologia e Metalogenia IGCE- UNESP Universidade Estadual Paulista, Av. 24A, 1515-Bela Vista
dc.description.affiliationUnespPrograma de Pós-Graduação em Geociências IGCE UNESP-Univ Estadual Paulista
dc.description.affiliationUnespDepartamento de Petrologia e Metalogenia IGCE- UNESP Universidade Estadual Paulista, Av. 24A, 1515-Bela Vista
dc.format.extent21-46
dc.identifierhttp://dx.doi.org/10.5016/geociencias.v39i1.14661
dc.identifier.citationGeociencias, v. 39, n. 1, p. 21-46, 2020.
dc.identifier.doi10.5016/geociencias.v39i1.14661
dc.identifier.issn1980-900X
dc.identifier.issn0101-9082
dc.identifier.scopus2-s2.0-85098447221
dc.identifier.urihttp://hdl.handle.net/11449/207033
dc.language.isopor
dc.relation.ispartofGeociencias
dc.sourceScopus
dc.subjectAçungui Supergroup
dc.subjectGeochemistry
dc.subjectGeology
dc.subjectMetabasic
dc.titleGeology and geochemistry of metabasic rocks from aÇungui supergroup, north of quarenta oitava shear zone, south of sÃo paulo stateen
dc.titleGeologia E Geoquímica Das Rochas Metabásicas Do Supergrupo Açungui A Norte Da Zona De Cisalhamento Quarenta Oitava, Sul Do Estado De São Paulopt
dc.typeArtigo

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