| Revue: | Anais da Academia Brasileira de Ciencias |
| Base de datos: | PERIÓDICA |
| Número de sistema: | 000436254 |
| ISSN: | 0001-3765 |
| Autores: | Arena, Karine da Rosa1 Hartmann, Léo Afraneo1 Lana, Cristiano de Carvalho2 Queiroga, Gláucia Nascimento2 Castro, Marco Paulo de2 |
| Instituciones: | 1Universidade Federal do Rio Grande do Sul, Instituto de Geociencias, Porto Alegre, Rio Grande do Sul. Brasil 2Universidade Federal de Ouro Preto, Escola de Minas, Ouro Preto, Minas Gerais. Brasil |
| Año: | 2020 |
| Volumen: | 92 |
| Número: | 1 |
| País: | Brasil |
| Idioma: | Inglés |
| Tipo de documento: | Artículo |
| Enfoque: | Analítico, descriptivo |
| Resumen en inglés | 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 (>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 |
| Disciplinas: | Geociencias |
| Palabras clave: | Geología, Geoquímica, Isótopos del boro, Turmalinas, Corteza oceánica |
| Keyword: | Geology, Geochemistry, Boron isotopes, Tourmalines, Oceanic crust |
| Texte intégral: | Texto completo (Ver HTML) Texto completo (Ver PDF) |
