Mendes, Mônica de Cássia OliveiraLagoeiro, Leonardo Evangelista2014-11-272014-11-272012MENDES, M.; LAGOEIRO, L. E. Microstructures, crystallographic fabric development and deformation mechanisms in natural hematite aggregates deformed under varied metamorphic conditions. Journal of Structural Geology, v. 40, p. 29-43, 2012. Disponível em: <http://www.sciencedirect.com/science/article/pii/S0191814112001034>. Acesso em: 30 set. 2014.0191-8141http://www.repositorio.ufop.br/handle/123456789/4045Naturally deformed hematite aggregates from 15 different iron ore mines located in Quadrilátero Ferrífero region, Brazil, were analyzed in order to verify the influence of increasing temperature and deformation intensity on their microstructural and textural aspects as well as the deformation mechanisms associated with the metamorphic conditions. The electron backscattered diffraction (EBSD) technique was applied in order to get qualitative and quantitative data concerning with microstructural parameters, crystallographic preferred orientation (CPO) and misorientation between hematite grains. The microstructures of these aggregates vary from randomly oriented hematite grains with approximately equant grains, to strongly oriented and elongated grains following the increase in deformational and metamorphic polarity toward east in the region. In the low deformation domain (western region) the deformation mechanisms are typically microfracturing and dissolution precipitation creep for magnetite rich aggregates. In the high-strain domain (eastern region), the deformation is accommodated by a combination of basal intracrystalline slip (c) (<a>) and grain boundary sliding, with rotation around hematite [c] axis. No evidences for recrystallization processes in these aggregates can be supported by our results, probably due to the superposition of subsequent processes.en-USCrystallographic preferred orientationIron formationsHematiteElectron backscattered diffractionDeformation mechanismsArtigo publicado em periodicoO periódico Journal of Structural Geology concede permissão para depósito deste artigo no Repositório Institucional da UFOP. Número da licença: 3481460433999.https://doi.org/10.1016/j.jsg.2012.04.005