Revista Brasileira de Geociências, 09/01/2001, Vol.31(3), pp.315-328
The paper describes the result of a 1:25,000 scale geologic mapping of a 820 sq. km. area located at a portion of the contact between the Archean and Proterozic terrains between Crixas and Cedrolina, Goias, central Brazil. The Archean terrains comprise parts of the Crixas, Guarinos, and Pilar de Goias greenstone belts, the Caiamar Complex and the Moquem Block. The greenstone belts consist of different volumes of low-grade metakomatiites, metabasalts, siliciclastic and chemical metasedimentary rocks, which differ in structure and metamorphic style. The Caiamar complex consists of tonalite gneisses and a tonalite intrusion, subordinately mafic dikes metamorphosed under mid- to high-grade amphibolite facies in the former, and greenschist facies in the latter. The Moquem block consists of tonalite and granodiorite gneisses, as well as a mafic dike swarm and gabbro and pyroxenite intrusions metamorphosed under mid- to high-grade amphibolite facies. The Proterozoic rocks overthrust the Archean rocks and consist of metasedimentary and metavolcanosedimentary units. The latter may be subdivided into at least three thrust-slices that contrast in rock assemblage, structural pattern and metamorphic grade. The vergence of the Proterozoic associations is towards the south-southeast, in contrast with the general easterly vergence of the Brasilia Belt towards the Sao Francisco Craton.
Areal Geology ; Amphibolite Facies ; Archean ; Areal Geology ; Brasilia Belt ; Brazil ; Caiamar Complex ; Cedrolina Brazil ; Crixas Belt ; Crixas Brazil ; Dikes ; Diorites ; Facies ; Faults ; Goias Brazil ; Goias Massif ; Greenstone Belts ; Guarinos Belt ; Igneous Rocks ; Intrusions ; Lithostratigraphy ; Mandinopolis Shear Zone ; Mapping ; Metamorphic Belts ; Metamorphic Rocks ; Mineral Composition ; Moquem Block ; Petrography ; Pilar De Goias Belt ; Plutonic Rocks ; Precambrian ; Proterozoic ; Shear Zones ; South America ; Stratigraphic Units ; Structural Analysis ; Tectonics ; Terranes ; Thrust Sheets ; Tonalite ; Upper Precambrian ; Vergence;
Revista Brasileira de Geociências
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