Evaluation of the contributions of possible sources to the leucosome of the diatexite of Socorro-Guaxupe Nappe, in the Alfenas Region, MG, Brazil

Autor(es)

Tasco, Lizeth Hernandez ^[1] ; Moraes, Renato ^[2]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Geociencias, Programa Geociencias Mineral & Petrol, Sao Paulo, SP - Brazil

^[2] Univ Sao Paulo, Inst Geociencias, Dept Mineral & Geotecton, Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: BRAZILIAN JOURNAL OF GEOLOGY; v. 49, n. 1 2019.
• Citações Web of Science: 0

Resumo

The Socorro-Guaxupe Nappe crops out in southern Minas Gerais and it has an intermediate unit called Metaxite Unit, dominated by diatexites at its base, with large volumes of leucosome and schollen of stromatic garnet-biotite metatexite. Leucosome within the schollen crystallized via fractional crystallization and is dominated by plagioclase and quartz, although K-feldspar might be present. However, the larger volume of the coarse-grained leucosome, that dominates the unit, has granite, sometimes close to minimum granite composition. So, its formation, after partial melting, involved, segregation, fractional crystallization and accumulation. Proportions of leucosome / residue and leucosome / residue / peritectic phases indicate that the leucosome crystallized from more melt than a pelite source could produce, and probably diatexite worked as a pre-magmatic chamber and stocked melt produced from the granulites sitting at its bottom. Large proportion of biotite crystallized in the residue was formed due to equalization of water chemical potential between residue and leucosome. (AU)

• Processo FAPESP: 16/22627-3 - Metamorfismo e fusão parcial em Orógenos antigos II
• Beneficiário: Renato de Moraes
• Linha de fomento: Auxílio à Pesquisa - Regular