Tectônica De Nappes Na Região De Ouro Fino, Conceição Do Mato Dentro, Mg

Abstract

The region around the District ofOuro Fino (Conceição do Mato Dentro, MG) is located on the southeastern bord er of the Espinhaço mountain range, where granite-gneíssíc (Basal Com plex) and Iow grade rnetasedimentary rocks can be found (Meta sedimentary Sequences I and II). Fine to coarse c1astic rocks (phyll ítes, quar tzites, metacon glomerates) dominate in these sequences. Basic metavolcanic rocks are less frequento The rocks in this region are intensively defonned showing a strong tangenci al , with mass transport from east to west shown by the general recronic struc tures, syn-mylonitic foliation paralleI to So' and also by smaller struc tures like pressure shadows, geain rotation, S and C surfaces, stretching Iineation, among oth ers. The type of the deformation is non-coaxial and heterogeneou s. Th e tectoni c stacking of similar stratigraphic uniti es, individuali zed by slices of gneissic mylonitic rocks, charac terize struc tures fonned by nap pe-tectonics.

Caracterização dos contaminantes do minério de ferro do depósito mineral da Serra do Sapo, Conceição do Mato Dentro, Minas Gerais

“…Cristais de granada (Figura 6H) descritos como espessartita são acessórios nas amostras de ITX, e também são descritas em hematita compacta da região sul da Serra do Espinhaço (Almeida- Abreu et al, 1988;Almeida Abreu, 1993;Almeida-Abreu e Renger, 2002).…”

“…A Serra do Sapo, localizada entre os municípios de Conceição do Mato Dentro e Alvorada de Minas, na região central do estado de Minas Gerais, está inserida na borda leste da Serra do Espinhaço Meridional. Essa região compreende as principais ocorrências de formação ferrífera conhecidas na Serra do Espinhaço (Knauer, 2007), abrangendo os grupos São José (Rolim, 2016) e Serra da Serpentina (Almeida Abreu, 1989;Zacchi, 2010;Chemale et al, 2012;Dossin et al, 1985;Grossi-Sad e Magalhães, 1989;Almeida-Abreu et al, 1988;Rolim e Rosière, 2011).…”

Tectonic evolution of the Southern Espinhaço Front in Serra do Cipó-MG

“…This formation is composed, at is base, by decametric quartzite lenses interlayerd with schist, followed by characteristically hematite-bearing, white-greenish schist, which grades to gray-silver banded phyllite, also bearing hematite and containing graphite-rich lenses. The Meloso Formation is gradually topped by the Serra do Sapo Formation (Almeida-Abreu et al, 1989), composed predominantly by banded iron formations, locally followed by discontinuous layers of dolomite at the top. Sparse lenses of quartzite, schist, phyllite and banded iron-manganese-rich rocks (Figure 9).…”

“…However, within the scope of our work, it is also worth mentioning the Itapanhoacanga Formation (Almeida-Abreu et al, 1989), a member of the Mesoproterozoic Serra de São José Group (13), defined by Rolim (2016) in the region of Conceição do Mato Dentro. In similar fashion to the Meloso Formation and the Costa Sena Group, the Serra de São José Group has never been described in our study area, but has been identified in the Serpentina Range.…”

“…The São João da Chapada Formation, an alluvial-fan sequence divided in four levels: A, B, C and D (Pflug, 1968;Schöll and Fogaça, 1979) A) The Lapão Formation (Rolim et al, 2016) contains metaconglomerate and medium to coarse-grained quartzite. The metaconglomerate clasts are mostly constituted by rocks from the underlying Serra do Sapo Formation B) The Itapanhoacanga Formation (Almeida-Abreu et al, 1989), comprising thick packages of deep-marine fan quartzite, often ferruginous and sericitic. Intercalations of schist and matrixsupported metaconglomerate also occur, with the coarser levels becoming finer and less frequent upper within the unit, giving place to scattered pebbles and coarse-grained quartzite.…”