摘要：Geology and petrography of the Glória Quartz-Monzodiorite, Mineiro Belt, southern portion of
the São Francisco Craton, Minas Gerais State.
Mafic and felsic plutons of the Mineiro Belt occur nearby the Lavras and Conselheiro Lafaiete cities, in
the southern portion of the São Francisco Craton. The Glória Quartz-Monzodiorite is a small mafic
intrusion (9km2) emplaced into schists, metapelites, and amphibolites associated with the Rio das Mortes
Greenstone Belt. This pluton bears ultramafic and amphibolite xenoliths, and is intruded by pegmatite
and granitic dikes of the Ritápolis Granitoid. The Glória Quartz-Monzodiorite includes diorites, quartz-
diorites, quartz-monzodiorites, and tonalites. These rocks are subdivided into three coeval granolumetric
facies that may represent members of associated subalkaline series resulting from differentiation of a
parental andesitic/dioritic liquid. The primary mineral assemblage of the Glória Quartz-Monzodiorite
was overprinted by a greenschist metamorphic paragenesis composed of actinolite, albite, sphene, and
epidote. Actinolite was further replaced by metassomatic biotite taken as derived from a potassic fluid
influx associated with pegmatite and granitic dikes of the Ritápolis Granitoid. The metamorphic and
metassomatic mineral assemblages of the Glória Quartz-Monzodiorite may have taken place in the 2.131
± 4 Ma and 2.121 ± 7 Ma time range, according to available minimum ages from the crystallization of
Brumado Diorite and Ritapolis Granitoid. Therefore, both processes are probably tectonically related
with the Paleoproterozoic evolution of the Mineiro Belt.
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