Salvato in:
| Autore principale: | |
|---|---|
| Natura: | Artículo científico |
| Lingua: | en |
| Pubblicazione: |
Academia Brasileira de Ciências
2006
|
| Soggetti: | |
| Accesso online: | https://www.redalyc.org/articulo.oa?id=32778313 |
| Tags: |
Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
|
Sommario:
- The Glória quartz-monzodiorite: isotopic and chemical evidence of arc-related magmatism in the central part of the paleoproterozoic Mineiro belt, Minas Gerais State, Brazil Umberto G. Cordani Ciro Alexandre Ávila Héctor R. Barrueto Ronaldo M. Pereira Veridiana T.S. Martins Liu Dunyi Wilson Teixeira Multidisciplinaria (Ciencias Naturales y Exactas) Sm Pb SHRIMP Nd isotopes monzodiorite Mineiro belt The Glória quartz-monzodiorite, one of the mafic plutons of the Paleoproterozoic Mineiro belt, is intrusiveinto banded gneisses, amphibolites, schists and phyllites of the Rio das Mortes greenstone belt, in the southernportion of the São Francisco Craton, State of Minas Gerais, Brazil. The Glória quartz-monzodiorite yieldsa SHRIMP U-Pb zircon age of 2188 ± 29 Ma, suggesting a tectonic relationship with the pre-collisionalphase of the Mineiro belt. According to the Nd isotopic evidence (εNd(T) = 3.4; TDM = 2.68 Ga) theoriginal magmas was formed by a mixture among Archean crustal material and Paleoproterozoic juvenilemagma. The Glória quartz-monzodiorite shows metaluminous and calc-alkaline tendency with intermediateK content, comparable to that of volcanic-arc rocks. The primary mineralogical assemblage was partlymodified by metamorphism, dated between 21312121 Ma in nearby coeval plutons. Such metamorphism issignificantly older than the reported metamorphic episodes of the Mineiro belt in the Quadrilátero Ferríferoregion (20592041 Ma) in the eastern portion of the study area. This evidence, together with chemicaland isotopic data from other mafic and felsic plutons coeval with the Glória quartz-monzodiorite, indicate atectonic and magmatic migration within the Mineiro belt from west to east. 2006 artículo científico 0001-3765 https://www.redalyc.org/articulo.oa?id=32778313 en http://www.redalyc.org/revista.oa?id=327 Anais da Academia Brasileira de Ciências application/pdf Academia Brasileira de Ciências Anais da Academia Brasileira de Ciências (Brasil) Num.3 Vol.78