Agpaitic Alkaline Rocks in Southern Brazilian Platform: A Review

Autor(es)

Gomes, Celso de Barros ^[1] ; Azzone, Rogerio Guitarrari ^[1] ; Rojas, Gaston Eduardo Enrich ^[1] ; Guarino, Vincenza ^[2] ; Ruberti, Excelso ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Geosci, BR-05508080 Sao Paulo - Brazil

^[2] Univ Napoli Federico II, Dipartimento Sci Terra Ambiente & Risorse, I-80126 Naples - Italy

• Tipo de documento: Artigo de Revisão
• Fonte: MINERALS; v. 11, n. 9 SEP 2021.
• Citações Web of Science: 0

Resumo

General information is presented on ten agpaitic occurrences located in southern Brazil and at the border between Brazil and Paraguay. All the Brazilian agpaitic rocks are Late Cretaceous in age, whereas the Paraguayan ones are older than Early Triassic. The most significant occurrence is Pocos de Caldas, the largest alkaline massif in South America. In general, these agpaitic rocks contain mineral assemblages that indicate presence of typical halogen-bearing Na-Ca-HFSE phases, eudialyte-, rinkite- and wohlerite-group minerals being the most frequent ones. However, these associations are indeed more complex in terms of composition, with accessory phases in some cases consisting of various minerals, including U-Th oxides/silicates, Nb oxides, REE-Sr-Ba bearing carbonates-fluorocarbonates-phosphates-silicates and Zr-Na rich silicates. They usually form late magmatic stage to hydrothermal/deuteric assemblages linked with coarse and fine-grained, mainly silica-undersaturated evolved rocks. Data also indicate significant differences in type, amount and composition of agpaitic minerals in all investigated occurrences. (AU)

• Processo FAPESP: 19/13174-3 - Aspectos gerais do magmatismo alcalino na região meridional da Plataforma Brasileira
• Beneficiário: Celso de Barros Gomes
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 19/22084-8 - A Província Magmática Paraná: petrogênese, cronologia e impacto ambiental do magmatismo toleítico, alcalino e silícico Cretáceo na Plataforma Brasileira
• Beneficiário: Valdecir de Assis Janasi
• Modalidade de apoio: Auxílio à Pesquisa - Temático