Compositional variation in Zr-, Nb-, and Ti-sorosilicates and cyclosilicates from agpaitic alkaline rocks and its petrological significance

• Grant number: 10/20476-1
• Support Opportunities: Regular Research Grants
• Start date: May 01, 2011
• End date: April 30, 2013
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Principal Investigator: Gaston Eduardo Enrich Rojas
• Grantee: Gaston Eduardo Enrich Rojas
• Host Institution: Instituto de Geociências (IGC). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated researchers: Excelso Ruberti ; Rogério Guitarrari Azzone

Abstract

This research project aims the characterization of the chemical composition of cuspidine-wöhlerite, mosandrite, and eudialyte mineral groups. These are rare Zr-, Ti-, Nb- and REE-rich sorosilicates and cyclosilicates and are restricted to agpaitic alkaline rocks. Analytical procedures will combine micro-beam techniques, such as electron microprobe, for determination of major and minor elements, and laser ablation coupled to a mass spectrometer, for trace elements analyses.The desired scientific contributions include a thorough crystallochemical study, as well as the textural characterization and petrological contextualization of such minerals in some alkaline occurrences from South American Platform. The crystallochemical study of each mineral phase will emphasize the cationic distribution of chemical elements, identification of compositional variations, mechanisms and extensions of ionic substitutions. In addition, the textural observations and the quantification of trace elements might provide information about the crystallization environment, allowing for the unraveling of magmatic/hydrothermal history and possible magmatic reactions involved in the genesis and evolution of these accessory minerals. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

ENRICH ROJAS, GASTON EDUARDO; RUBERTI, EXCELSO; AZZONE, ROGERIO GUITARRARI; GOMES, CELSO DE BARROS. Minerais do grupo da eudialita da suíte alcalina Monte de Trigo, Brasil: composição e implicações petrológicas. BRAZILIAN JOURNAL OF GEOLOGY, v. 46, n. 3, p. 411-426, SEP 2016. (13/18073-4, 12/06082-6, 10/20476-1)