Zn-Pb mineralizationd of de Salobo deposit, Porteirinha (MG).
Authors
Fernando Antônio Crocco
Diretoria de Desenvolvimento de Projetos Minerais, Companhia Vale do Rio Doce
Francisco Robério de Abreu
Noevaldo Teixeira
Diretoria de Desenvolvimento de Projetos Minerais, Companhia Vale do Rio Doce
Fernando Luis Lucena Cançado
Diretoria de Desenvolvimento de Projetos Minerais, Companhia Vale do Rio Doce
Juliano Duarte Maciel
Magnesita S.A.
Florivaldo Sena
Diretoria de Desenvolvimento de Projetos Minerais, Companhia Vale do Rio Doce
Maurício Moacir Ramos
Diretoria de Desenvolvimento de Projetos Minerais, Companhia Vale do Rio Doce
Keywords:
Zinco, chumbo, depósitos minerais, Salobro
Abstract
A regional prospect program carried out by CVRD since the 70´s to find out gold and base metals deposits discovered the Salobro Zn-Pb deposit among others. It is located in the Porteirinha district in the northern area of Minas Gerais state. Three units were defined in the Riacho dos Machados Group (A, B, C from bottom to top), an Arquean or Paleoproterozoic metassedimentary sequence. The geological evaluation defined 8 mt@7% (Zn+Pb) measured for a cut off of 5% and a minimum width of 2,00 m. The Riacho dos Machados Group hosts the mineralization in a metachert layer in the unit B. The mineralization is essentially stratabound. Sphalerite and galena are the ore minerals, both with coarse granulometry imposed by metamorphic processes. The iron content of sphalerite ranges from 2,4% to 7,9%. The mineralogy of the ore-gangue is composed mainly by amphiboles, quartz and magnetite. Pyrite and pyrrhotite are present disseminated in the ore and in several massive and thick bodies. In spite of being a small deposit, Salobro has favorable features for exploitation.
