| Texto completo | |
| Autor(es): |
Gengo, Rafaela Machado
;
Moraes, Renato
;
Batista, Laisa de Assis
;
Santos, Caio Arthur
;
Szabo, Gergely Andres Julio
Número total de Autores: 5
|
| Tipo de documento: | Artigo Científico |
| Fonte: | LITHOS; v. 456-457, p. 18-pg., 2023-08-05. |
| Resumo | |
The Southernmost Brasilia Orogen surrounds the southern margins of the Sa similar to o Francisco Craton. It exposes a structural window with a WNW-ESE direction formed by the Archean-Paleoproterozoic basement reworked by the Campo do Meio Shear Belt. Using metamorphic modeling, geothermobarometry, and U-Pb dating of zircon and monazite, this study established the pressure-temperature-time (P-T-t) evolution of the Colo<SIC>nia metapelite, one of the main units of the Campo do Meio Shear Belt. This revealed a clockwise path with metamorphic peak conditions at 706 +/- 16 degrees C and 9.7 +/- 0.7 kbar on a staurolite-kyanite-muscovite-garnet-biotite schist, with cooling at-600 degrees C and -6 kbar. Forward metamorphic modeling based on the whole-rock composition of this sample supports partial melting in the staurolite stability field, facilitated by water influx. Water-fluxed anatexis promoted dissolution of detrital zircon grains. These processes, occurring during prograde metamorphism, are influenced by temperature, crystal size-distribution, bulk-rock composition, and the permanence of the rock at the thermal peak. Analysis of the zircon overgrowth zones, which were linked to peak metamorphic conditions, produced an age of 605 +/- 7 Ma. The monazite age of 580 +/- 5 Ma was associated with later syntectonic melt crystallization. The clockwise P-T-t path of the Colo<SIC>nia metapelite is similar to the evolution of Neoproterozoic units from the Southernmost Brasilia Orogen. However, the degree of dissolution in detrital zircon grains restricts accurate evaluation of the possible stratigraphic correlations proposed in the literature. (AU) | |
| Processo FAPESP: | 16/22627-3 - Metamorfismo e fusão parcial em Orógenos antigos II |
| Beneficiário: | Renato de Moraes |
| Modalidade de apoio: | Auxílio à Pesquisa - Regular |