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Xenocryst and Antecryst compositional influence in basic to ultrabasic alkaline magmas

Grant number: 17/03768-8
Support type:Regular Research Grants
Duration: July 01, 2017 - December 31, 2019
Field of knowledge:Physical Sciences and Mathematics - Geosciences
Principal Investigator:Rogério Guitarrari Azzone
Grantee:Rogério Guitarrari Azzone
Home Institution: Instituto de Geociências (IGC). Universidade de São Paulo (USP). São Paulo , SP, Brazil
Assoc. researchers:Celso de Barros Gomes ; Excelso Ruberti ; Gaston Eduardo Enrich Rojas

Abstract

This research projetc aims to study the xenocryst/antecryst compositional influence in basic to ultrabasic alkaline magmas. This question is specially important in the study of lamprophyres (mesocratic to melanocratic porphyritic rocks), of mafic-ultramafic cumulate bodies and of kimberlitic/kamafugitic pipes related to the Cretaceous alkaline magmatism in the Brazilian Platform. All these magmatic types are representative of complex plumbing systems and present distinct crystal populations with different genetic significance. This project will contribute in specific topics based on new concepts not yet explored for the Brazilian alkaline occurrences, such as 1) the identification and characterization of different crystal populations in heterogeneous and hybrid rocks (e.g., phenocrysts vs. antecrysts, cognate crystals vs. xenocrysts), 2) the compositional influence that non-equilibrium crystal cargo (xenocrysts or antecrysts) exerts on the bulk composition of the system and 3) the petrological processes that could be inferred from the understanding of these assemblages. The crystal/melt equilibrium relations will be evaluated based on textural criteria (types of zoning, corrosion and/or resorption features, overgrowths, etc.) as well as major and trace element compositional trends and in situ isotopic ratios. The schedule comprehends petrographic analysis by optical microscopy, scanning electron microscopy, cathodoluminescence, in situ punctual chemical analysis by electron microprobe (WDS) and by LA ICP-MS, as well as in situ isotopic ratios, mainly 87Sr/86Sr, by LA-MC-ICP-MS. Combining textural, compositional and isotopic criteria between crystals or stages of mineral crystallization, we will attribute the genetic significance of the crystal populations that these lithotypes present and will understand better the complex magmatic processes involved in their evolution. Based on this new understanding, new and more detailed petrological models will be proposed. (AU)

Scientific publications (6)
(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)
ALMEIDA, VIDYA VIEIRA; JANASI, VALDECIR DE ASSIS; AZZONE, ROGERIO GUITARRARI; FALEIROS, FREDERICO MEIRA. Crustal contamination and genesis of transitional alkaline-tholeiitic intrusions: Insights from the Jose Fernandes Suite, Parana Magmatic Province, Brazil. LITHOS, v. 342, p. 59-75, OCT 2019. Web of Science Citations: 0.
CHMYZ, LUANNA; ARNAUD, NICOLAS; BIONDI, JOAO CARLOS; AZZONE, ROGERIO GUITARRARI; BOSCH, DELPHINE. Hf-Pb isotope and trace element constraints on the origin of the Jacupiranga Complex (Brazil): Insights into carbonatite genesis and multi-stage metasomatism of the lithospheric mantle. GONDWANA RESEARCH, v. 71, p. 16-27, JUL 2019. Web of Science Citations: 0.
CELSO DE BARROS GOMES; PIERO COMIN-CHIARAMONTI; ROGÉRIO GUITARRARI AZZONE; EXCELSO RUBERTI; GASTON EDUARDO ENRICH ROJAS. Cretaceous carbonatites of the southeastern Brazilian Platform: a review. BRAZILIAN JOURNAL OF GEOLOGY, v. 48, n. 2, p. -, Jun. 2018.
AZZONE, ROGERIO GUITARRARI; RUBERTI, EXCELSO; LOPES DA SILVA, JULIO CESAR; GOMES, CELSO DE BARROS; ENRICH ROJAS, GASTON EDUARDO; BEZERRA MAIA DE HOLLANDA, MARLA HELENA; GAETA TASSINARI, COLOMBO CELSO. Upper Cretaceous weakly to strongly silica-undersaturated alkaline dike series of the Mantiqueira Range, Serra do Mar alkaline province: Crustal assimilation processes and mantle source signatures. BRAZILIAN JOURNAL OF GEOLOGY, v. 48, n. 2, p. 373-390, APR-JUN 2018. Web of Science Citations: 2.
GOMES, CELSO DE BARROS; COMIN-CHIARAMONTI, PIERO; AZZONE, ROGERIO GUITARRARI; RUBERTI, EXCELSO; ENRICH ROJAS, GASTON EDUARDO. Cretaceous carbonatites of the southeastern Brazilian Platform: a review. BRAZILIAN JOURNAL OF GEOLOGY, v. 48, n. 2, p. 317-345, APR-JUN 2018. Web of Science Citations: 4.

Please report errors in scientific publications list by writing to: cdi@fapesp.br.