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The Transition from Miaskitic to Agpaitic Rocks, as Highlighted by the Accessory Phase Assemblages in the Passa Quatro Alkaline Complex (SouthEastern Brazil)

2019; Mineralogical Association of Canada; Volume: 57; Issue: 3 Linguagem: Inglês

10.3749/canmin.1800073

1499-1276

Vincenza Guarino, Roberto dè Gennaro, Leone Melluso, Excelso Ruberti, Rogério Guitarrari Azzone,

Geochemistry and Elemental Analysis

Research Article| May 16, 2019 The Transition from Miaskitic to Agpaitic Rocks, as Highlighted by the Accessory Phase Assemblages in the Passa Quatro Alkaline Complex (SouthEastern Brazil) Vincenza Guarino; Vincenza Guarino § Dipartimento di Scienze della Terra, dell'Ambiente e delle Risorse, Università di Napoli Federico II, Complesso Universitario Monte Sant'Angelo, Ed. L, Via Cintia 26, 80126 Naples, Italy § Corresponding author e-mail address: vincenza.guarino@unina.it Search for other works by this author on: GSW Google Scholar Roberto de' Gennaro; Roberto de' Gennaro Dipartimento di Scienze della Terra, dell'Ambiente e delle Risorse, Università di Napoli Federico II, Complesso Universitario Monte Sant'Angelo, Ed. L, Via Cintia 26, 80126 Naples, Italy Search for other works by this author on: GSW Google Scholar Leone Melluso; Leone Melluso Dipartimento di Scienze della Terra, dell'Ambiente e delle Risorse, Università di Napoli Federico II, Complesso Universitario Monte Sant'Angelo, Ed. L, Via Cintia 26, 80126 Naples, Italy Search for other works by this author on: GSW Google Scholar Excelso Ruberti; Excelso Ruberti Instituto de Geociências, Universidade de São Paulo, Rua do Lago 562, 05508-080 São Paulo, Brazil Search for other works by this author on: GSW Google Scholar Rogério G. Azzone Rogério G. Azzone Instituto de Geociências, Universidade de São Paulo, Rua do Lago 562, 05508-080 São Paulo, Brazil Search for other works by this author on: GSW Google Scholar Author and Article Information Vincenza Guarino § Dipartimento di Scienze della Terra, dell'Ambiente e delle Risorse, Università di Napoli Federico II, Complesso Universitario Monte Sant'Angelo, Ed. L, Via Cintia 26, 80126 Naples, Italy Roberto de' Gennaro Dipartimento di Scienze della Terra, dell'Ambiente e delle Risorse, Università di Napoli Federico II, Complesso Universitario Monte Sant'Angelo, Ed. L, Via Cintia 26, 80126 Naples, Italy Leone Melluso Dipartimento di Scienze della Terra, dell'Ambiente e delle Risorse, Università di Napoli Federico II, Complesso Universitario Monte Sant'Angelo, Ed. L, Via Cintia 26, 80126 Naples, Italy Excelso Ruberti Instituto de Geociências, Universidade de São Paulo, Rua do Lago 562, 05508-080 São Paulo, Brazil Rogério G. Azzone Instituto de Geociências, Universidade de São Paulo, Rua do Lago 562, 05508-080 São Paulo, Brazil § Corresponding author e-mail address: vincenza.guarino@unina.it Publisher: Mineralogical Association of Canada First Online: 06 May 2019 Online Issn: 1499-1276 Print Issn: 0008-4476 © 2019 Mineralogical Association of Canada The Canadian Mineralogist (2019) 57 (3): 339–361. https://doi.org/10.3749/canmin.1800073 Article history First Online: 06 May 2019 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Vincenza Guarino, Roberto de' Gennaro, Leone Melluso, Excelso Ruberti, Rogério G. Azzone; The Transition from Miaskitic to Agpaitic Rocks, as Highlighted by the Accessory Phase Assemblages in the Passa Quatro Alkaline Complex (SouthEastern Brazil). The Canadian Mineralogist 2019;; 57 (3): 339–361. doi: https://doi.org/10.3749/canmin.1800073 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyThe Canadian Mineralogist Search Advanced Search Abstract The Passa Quatro alkaline complex is one of the main intrusions in the Serra do Mar Cretaceous to Paleogene Igneous Province of southeastern Brazil. It is composed mainly of nepheline syenites and alkali syenites, with minor phonolitic dikes. The dominant felsic phases are potassic feldspar and nepheline, with minor sodic plagioclase in less silica-undersaturated rocks. The main mafic phases are clinopyroxene, amphibole, biotite, and oxides. The wealth of accessory phases includes titanite, eudialyte, astrophyllite–kupletskite, F-disilicates, phosphates, phosphosilicates, and F-REE-carbonates, with their specific ranges of composition. These accessory minerals often mantle zircon and fluorite corroded crystals, evidence of (1) the petrographic transition from miaskitic to agpaitic in the same rock, and (2) a decrease in the activity of fluorine in the coexisting residual magmas, from the stability range of fluorite to that of F-poorer disilicates. There is also a major role, as yet undervalued, for manganese in the phase stability of the various accessory phases in rocks/magmas devoid of magnesium. The three neighboring complexes of Itatiaia, Passa Quatro, and Poços de Caldas have significant differences in the types and amounts of agpaitic minerals in their peralkaline rocks. The Passa Quatro intrusion (with aegirine, titanite, and minor eudialyte) can be considered slightly more silica undersaturated and peralkaline than the nearby Itatiaia complex and has transitional features towards the highly agpaitic nepheline syenites of Poços de Caldas (with aegirine, titanite, eudialyte, and aenigmatite). Eudialyte and titanite represent accessory phases that influence the incompatible element behavior in the residual magmatic compositions (mostly phonolites and peralkaline phonolites) of the Serra do Mar potassic province. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.