DEPÓSITO DE GRAFITA DA FAZENDA TRAÍRAS (BA): UM EXEMPLO DE ROMBOCASMO DESENVOLVIDO EM UMA ZONA DE CISALHAMENTO

Résumé

A flaky graphite deposit is described with emphasis on the chemical-mineralogical characterization ofits main graphite bearing lithologies, namely graphite “gneisses” and graphitic breccias.The proposed geological model for the deposit is based on the development of a shear zone affectingarchean metamorphic rocks in a deep crustal environment which was the channelway for an ultrabasicintrusion.Graphite concentrations are restricted to milonitic belts which cut the ultrabasic intrusive.An attempt is made to compare the geological characteristics of this deposit with other graphite depositsin Brazil and elsewhere.