Magmatic evolution of the Piracaia Monzonitic-Monzodiorite Pluton

• Grant number: 06/00465-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: April 01, 2006
• End date: March 31, 2007
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Principal Investigator: Valdecir de Assis Janasi
• Grantee: Bruno Salmoni
• Host Institution: Instituto de Geociências (IGC). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The Piracaia Monzonitic-Monzodioritic Pluton is the main occurrence of lithophile element-rich basic-intermediate magmatism in the Neoproterozoic of the State of São Paulo. In view of its compositional and structural complexity, it has been the subject of several field, petrographic and geochemical works. These studies have contributed to the understanding of the underlying mantle and the evolution of magmatic suites with shoshonite affinities. Using a representative sample collection obtained by the supervisor during a detailed mapping of the pluton, the candidate will systematize the existing geological and petrographic data in a geographic information system, and will obtain new mineral chemical data, especially for mafic minerals (pyroxene, biotite, amphibole, opaque minerals), especially for the more evolved rocks, for which only a few analyses are available. These data, combined with new whole-rock trace-element analyses by ICP-MS, will allow a refining of the quantitative modelling of the magmatic evolution of the pluton.