Estratigrafia do domínio interno da faixa Paraguai na região de Nova Xavantina, Leste de Mato Grosso

Abstract

The geologic mapping of the Paraguay estern portion, near the city of Nova Xavantina, allowed the individualization of three lithostratigraphic units: (i) Bacuri Formation, constituted by banded iron formations and bedded metacherts; (ii) Antártico Formation, defined by immature lithotypes arranged in heterolytic facies growing-upward cycles of quartz-phyillite, metamarble, phyillite, calciferous phyillite, metasandstone feldspathic, metaconglomerate, metasiltstone and metagraywacke. These associations exhibit graded bedding, plane-parallel laminations, ripple-crossed and convolute and linsen stratification, which reflect the deposition by mixed processes (waves and tides); (iii) Touro Branco Formation, formed by mature quartz metasandstone and quartzite containing plane-parallel and low angle cross- tabular stratification with waved and erosion marks. The data suggest that the these units were deposited in a transgressive marine environment megacycle that envolvesd transitionally to near shore shallow facies.