Fácies sedimentares e Petrografia dos depósitos da Mina de Manganês do Azul, Serra dos Carajás, cráton amazônico

Abstract

The sedimentary rocks exposed in Blue Manganese Mine, located in the central portion of the Serra dos Carajás, exhibit a diverse assemblage of well-preserved primary sedimentary structures that allow a detailed study of facies level for interpretation of depositional processes related, which are presented in this work. These deposits are part of the Precambrian sedimentary cover in southeasten of the Amazonian Craton, whose sedimentary environments existed in this region and are related to changes in base level. The rocks of these deposits consist of tabular bodies of fine sandstones and pelites, presenting as the main structure parallel lamination, convolute lamination and truncated lamination of the low-angle similar to hummocky swaley. The analysis facies allowed the definition of five sedimentary facies, and through facies association, have been proposed as the depositional environment of marine platform, preserved from erosive events for the deposition of politic sediments in the region of the Blue mine.