@inproceedings{inproceedingsf397c069, title = {40Ar/39Ar dating of Mn-Iron ore of the Sapecado mine, quadrilátero ferrífero, Brazil}, author = {Spier, Carlos Alberto and Vasconcelos, Paulo Marcos and Oliveira, Sonia Maria Barros de}, year = {2004}, publisher = {IUGS}, booktitle = {International Geological Congress} }