Acessibilidade / Reportar erro

Structure of the Rio Mata Cavalo volcano-sedimentary sequence (Morro do Pilar, MG, Brazil) based on qualitative analysis of geophysical data

Ground geophysics, magnetometry and radiometry have been used to support geological survey of the prospecting area named Bueiro Target, of the Companhia Mineradora de Minas Gerais (COMIG), located southeast from Morro do Pilar, Serra do Espinhaço, Minas Gerais State. The integration of surface geological information and corresponding geophysical data defined four zones, named A, B, C and D. The A Zone, characterized by high magnetic susceptibility and low radiometric values, is composed by itabirites belonging to the Serra da Serpentina Group. The B Zone, part of this Group, is constituted by gray phyllites and meta-siltites, showing low magnetic susceptibility with interruptions in the contour lines, which are interpreted as due to the presence of thrust faults. The C Zone, related to the Rio Mata Cavalo Volcano-Sedimentary Sequence, is characterized by an expressive anomaly of total magnetic field, associated with mafic and ultramafic schists containing several lenses of iron formation and black carbonaceous phyllites; this zone hosts the most important gold geochemical anomalies in the studied area. The D Zone, which corresponds to sheared orthogneisses of the Dona Rita Complex, shows the highest radiometric values of Bueiro Target but has a very low magnetic response.

Serra do Espinhaço; Volcano-Sedimentary Sequence; Radiometric and Magnetometric Surveys; Gold


Sociedade Brasileira de Geofísica Av. Rio Branco, 156, sala 2510, 20043-900 Rio de Janeiro RJ - Brazil, Tel. / Fax: (55 21) 2533-0064 - São Paulo - SP - Brazil
E-mail: sbgf@sbgf.org.br