Data/hora: 11/06/2024 14:59:01

Provedor de dados: | 42
País: | Brazil
Título: | Geochemistry and δ11 B evolution of tourmaline from tourmalinite as a record of oceanic crust in the Tonian Ibaré ophiolite, southern Brasiliano Orogen
Autores: | ARENA,KARINE DA ROSA; HARTMANN,LÉO AFRANEO; LANA,CRISTIANO DE CARVALHO; QUEIROGA,GLÁUCIA NASCIMENTO; CASTRO,MARCO PAULO DE.
Data: | 2020-01-01
Ano: | 2020
Palavras-chave: | Boron isotopes; Geochemistry; Ibaré ophiolite; Tourmalinite; Southern Brasiliano Orogen.
Resumo: | Abstract  The isotopic and geochemical evolution of tourmaline constrain the processes of paleo-oceanic lithosphere in ophiolites. The Brasiliano Orogen is a major structure of South America and requires characterization for the understanding of Gondwana supercontinent evolution. We made a pioneering investigation of tourmaline from a tourmalinite in the Ibaré ophiolite by integrating field work with chemical analyses of tourmaline by electron microprobe (EPMA) and δ11B determinations via laser ablation inductively coupled plasma mass spectrometer (LA-ICP-MS). Remarkably massive tourmalinite (&gt;90 vol.% tourmaline, some chlorite) enclosed in serpentinite has homogeneous dravite in chemical and isotopic composition (δ11B = +3.5 to +5.2‰). These results indicate a geotectonic environment in the altered oceanic crust for the origin of the tourmalinite. This first δ11B characterization of tourmaline from tourmalinite sets limits to the evolution of the Neoproterozoic to Cambrian Brasiliano Orogen and Gondwana evolution.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652020000100603
Editor: | Academia Brasileira de Ciências
Relação: | 10.1590/0001-3765202020180193
Formato: | text/html
Fonte: | Anais da Academia Brasileira de Ciências  v.92 n.1 2020
Fonte: | info:eu-repo/semantics/openAccess