We present a comprehensive overview of the geochemical characteristics and evolution of the carbonatites from the southern Brazilian Platform (Paraná Basin). The carbonatites from different complexes display large compositional variability in terms of abundances of incompatible and rare earth elements. This is in agreement with an origin from heterogeneous lithospheric sources, as confirmed by isotopic data (see Speziale et al., this issue). The characteristic major and trace element abundances of these carbonatites present compelling evidence for invoking liquid unmixing as the main mechanism of their formation and evolution albeit few exceptions. We propose an evolutionary trend for the Brazilian carbonatites, which can be summarized as following: exsolution of the primary Ca- or Mg-carbonatitic liquids systematically takes place at the phonoliteperalkaline phonolite stage of magma differentiation; this is followed by progressive Fe-enrichment and by final emplacement of fluorocarbonatites associated with hydrothermal fluids.

Carbonatites from the Southern Brazilian platform. 1 / Speziale, Sergio; Castorina, Francesca; Censi, Paolo; de Barros Gomes, Celso; Soares Marques, Leila; Comin-Chiaramonti, Piero. - In: OPEN GEOSCIENCES. - ISSN 2391-5447. - 12:(2020), pp. 452-478. [10.1515/geo-2020-0050]

Carbonatites from the Southern Brazilian platform. 1

Francesca Castorina;
2020

Abstract

We present a comprehensive overview of the geochemical characteristics and evolution of the carbonatites from the southern Brazilian Platform (Paraná Basin). The carbonatites from different complexes display large compositional variability in terms of abundances of incompatible and rare earth elements. This is in agreement with an origin from heterogeneous lithospheric sources, as confirmed by isotopic data (see Speziale et al., this issue). The characteristic major and trace element abundances of these carbonatites present compelling evidence for invoking liquid unmixing as the main mechanism of their formation and evolution albeit few exceptions. We propose an evolutionary trend for the Brazilian carbonatites, which can be summarized as following: exsolution of the primary Ca- or Mg-carbonatitic liquids systematically takes place at the phonoliteperalkaline phonolite stage of magma differentiation; this is followed by progressive Fe-enrichment and by final emplacement of fluorocarbonatites associated with hydrothermal fluids.
carbonatite; Southern Brazilian platform; lithospheric mantle source; lithospheric mantle
01 Pubblicazione su rivista::01a Articolo in rivista
Carbonatites from the Southern Brazilian platform. 1 / Speziale, Sergio; Castorina, Francesca; Censi, Paolo; de Barros Gomes, Celso; Soares Marques, Leila; Comin-Chiaramonti, Piero. - In: OPEN GEOSCIENCES. - ISSN 2391-5447. - 12:(2020), pp. 452-478. [10.1515/geo-2020-0050]
File allegati a questo prodotto
File Dimensione Formato  
Speziale_Carbontites_2020.pdf

accesso aperto

Tipologia: Versione editoriale (versione pubblicata con il layout dell'editore)
Licenza: Creative commons
Dimensione 2.11 MB
Formato Adobe PDF
2.11 MB Adobe PDF Visualizza/Apri PDF

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/1470984
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 2
  • ???jsp.display-item.citation.isi??? 2
social impact