Plutonismo proterozoico en Antártida: el Granito Bertrab y su cortejo de diques
Bertrab Nunatak is located in the Vahsel Bay area, Weddell Sea, Antarctica. It is composed of a granitic body, «Granito Bertrab», cut by acid aplite/rhyolite and quartz veins) and basic dyke-swarms. Granito Bertrab is a coarse-grained, granophyric quartz-feldspar biotite granite with minor normativ...
| Autores: | , , , , |
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| Formato: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2000 |
| País: | Argentina |
| Recursos: | Consejo Nacional de Investigaciones Científicas y Técnicas |
| Repositorio: | CONICET Digital (CONICET) |
| Idioma: | español |
| OAI Identifier: | oai:ri.conicet.gov.ar:11336/156199 |
| Acesso em linha: | http://hdl.handle.net/11336/156199 |
| Access Level: | acceso abierto |
| Palavra-chave: | GRANITO BERTRAB EDAD ISOTÓPICA ANTÁRTIDA https://purl.org/becyt/ford/1.5 https://purl.org/becyt/ford/1 |
| Resumo: | Bertrab Nunatak is located in the Vahsel Bay area, Weddell Sea, Antarctica. It is composed of a granitic body, «Granito Bertrab», cut by acid aplite/rhyolite and quartz veins) and basic dyke-swarms. Granito Bertrab is a coarse-grained, granophyric quartz-feldspar biotite granite with minor normative corundum (1%) that indicates peraluminous affinities. Melanocratic calc-alkaline dykes, with labradorite-andesine and amphibole megacrysts, have a lamprophyric character. One of these is cut by a leucocratic dike, that represents the final stage in the magmatic activity. Petrological evidence indicates that there is a temporally, spatially and genetically intimate association bewteen the granite and the dykes. K-Ar data on samples of the granite give an age of 996 ± 40 Ma, and the Rb-Sr isochron age recalculated using the published data of Eastin and Faure give an age of 971 ± 8 Ma using five samples, and 992 ± 12 Ma when the aplitic member is not included. These results are in good agreement with the K-Ar age and mean that the Granito Bertrab was emplaced in the late Mesoproterozoic. |
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