Produção Nacional
GEOLOGIA DA SEQÜÊNCIA VULCANO-SEDIMENTAR DE ARENÓPOLlS (GO)
1986; Sociedade Brasileira de Geologia; Volume: 16; Issue: 2 Linguagem: Inglês
10.25249/0375-7536.1986217223
ISSN2177-4382
AutoresMárcio Martins Pimentel, Reinhardt A. Fuck,
Tópico(s)Geological formations and processes
ResumoThe Arenópolis volcano-sedímentary sequencê comprises two main lithologic uníts. The Córrego Santo Antônio unit occupies the western portion of the sequence and consista of a complex lithologic assemblage including metapelitic schist with intercalation of marble, metachert, fine-grained quartzite, and probable met abasalt. Metamorphosed mafic to ultramafic plutonic rocks such as amphibolite (metagabbro), metaperidotite, and serpentinite are common in thís unit. The Córrego da Onça unit forms the eastern part of the sequence and is separated from the former by a strip of banded and locally migmatized gneisses. It consists of three sub-units: a) the mafic sub-unit, made up mainly of metabasalt and meta-andesite: b) the intermedlate-felsic sub-unit, which includes andesitic to rhyolitic metavolcanics and metapyroclastics; and c) the metasedimentary sub-unit, composed of metagraywackes, feldspathic biotite schist and quartzite. Several small plutonic to sub-volcaníc bodies, varying in composition from gabbro to granite, intruded the Córrego da Onça unit . The lithological, structural, and metamorphic features identified in the Córrego da Onça unit suggest that it evolved in a tectonic setting similar to modem volcanic ares, in a subduction zone environment, while the Córrego Santo Antônio unit may be interpreted as an accretionary prism, adjacent to a volcanic front, formed in an environment similar to a modem trench/fore-arc region.
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