Please use this identifier to cite or link to this item: http://www.repositorio.ufop.br/jspui/handle/123456789/13478
Title: Mineralogical evolution of the northern Bossoroca ophiolite, São Gabriel terrane.
Authors: Massuda, Amanda Juliano
Hartmann, Leo Afraneo
Queiroga, Gláucia Nascimento
Castro, Marco Paulo de
Leandro, Carolina Gonçalves
Savian, Jairo Francisco
Keywords: Chromite-talc-magnesite granofels
Tourmalinite
Metasomatism
Aerogeophysics
Issue Date: 2020
Citation: MASSUDA, A. J. et al. Mineralogical evolution of the northern Bossoroca ophiolite, São Gabriel terrane. Brazilian Journal of Geology, v. 50, n. 4, p. e20190120, 2020. Disponível em: <https://www.scielo.br/scielo.php?pid=S2317-48892020000400307&script=sci_arttext&tlng=en>. Acesso em: 19 fev. 2021.
Abstract: Mineralogical evolution of ophiolites is significant to understand paleo-oceanic crust and mantle requiring multi-proxy techniques to identify steps in the processes. We studied the Bossoroca ophiolite from the southern Brasiliano Orogen, a prime example of Tonian accretion to an oceanic island arc. Integration of field geology, aeromagnetometry, aerogamaspectrometry, electron microprobe analyses, and compositional maps of minerals led to the decoding of oceanic and continental processes. The ophiolite is highly magnetic and low-K and is positioned at the base of the superstructure. We studied amphibolite, tourmalinite, and chromite-talc-magnesite granofels from the ophiolite, Capivaras diorite from the Cambaí Complex infrastructure and one metavolcanoclastic rock from the Vacacaí Group superstructure. Honblende is zoned in all rock types. Low-Ti hornblende is compatible with medium-pressure metamorphism at 7 kbar. This M1 to M2 amphibolite facies resulted in the widespread association of olivine + talc in metaserpentinite. Dravite is similar to tourmaline from the Ibaré ophiolite. Andesine and oligoclase are dominant and albite minor. Cr-spinel in granofels recrystallized in greenschist facies; host rock originated by carbonatization of serpentinite formed in the oceanic crust along with chloritite and tourmalinite. Serpentinite rare earth elements (REE) suggest origin in depleted mantle peridotite. The ophiolite evolved in the Adamastor Ocean until incorporation into the island arc.
URI: http://www.repositorio.ufop.br/jspui/handle/123456789/13478
metadata.dc.identifier.doi: http://dx.doi.org/10.1590/2317-4889202020190120
ISSN: 2317-4692
metadata.dc.rights.license: This is an open access article distributed under the terms of the Creative Commons license. Fonte: o PDF do artigo.
Appears in Collections:DEGEO - Artigos publicados em periódicos

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