The geochemistry of the Barra do Itapirapuã carbonatite (Ponta Grossa Arch, Brazil): A multiple stockwork

Paolo Censi, Ruberti, Castorina, Piero Comin-Chiaramonti, Andrade, Celso Gomes, Antonini

Risultato della ricerca: Article

20 Citazioni (Scopus)

Abstract

The Early Cretaceous Barra do Itapirapuā carbonatite, in southern Brazil, belongs to the initial stages of the alkaline carbonatitic magmatism in the Ponta Grossa Arch Province, as related to the opening of the south Atlantic Ocean. The magmatic evolution of the complex comprises four phases of intrusive carbonatite that are composed of medium- to coarse-grained Mg and Fe carbonatites with small volumes of late fine- to very fine-grained Mg carbonatites and show evidence of pervasive hydrothermal events. Drill core samples reveal the existence of silicate rocks of syenitic composition of two different origins. Among the silicate rocks, there are syenites of a likely magmatic origin, as well as fenites derived from the granitic protolith, which constitutes the wall rock of the complex. Fenitization around the Barra do Itapirapuā complex is mainly potassic, and fenites are Ca- and LOI-enriched in comparison with the magmatic syenites. Furthermore, the two types of silicate rocks differ in terms of REE and other trace elements. Associated syenites and carbonatites have similar Sr-Nd isotopic compositions, close to the Bulk Earth at 120 Ma. Mixing curves indicate that the carbonatite-syenite association may be accounted for by assimilation of up to 20% crustal material, whereas the late carbonatite composition is consistent with less than 10% assimilation of crustal rocks. An origin by liquid immiscibility for the carbonatite-syenite association can be considered, followed by magmatic differentiation through fractional crystallization of calcite and dolomite in the carbonatite magma. C-O stable isotopic data indicate further reequilibration under hydrothermal conditions at temperatures between 375 and 80 °C. © 2002 Elsevier Science Ltd. All rights reserved.
Lingua originaleEnglish
pagine (da-a)215-228
Numero di pagine14
RivistaJournal of South American Earth Sciences
Volume15
Stato di pubblicazionePublished - 2002

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carbonatite
arch
geochemistry
silicate
syenite
rock
magmatic differentiation
immiscibility
wall rock
protolith
fractional crystallization
dolomite
magmatism
rare earth element
isotopic composition
calcite
magma
trace element
Cretaceous
liquid

All Science Journal Classification (ASJC) codes

  • Geology
  • Earth-Surface Processes

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The geochemistry of the Barra do Itapirapuã carbonatite (Ponta Grossa Arch, Brazil): A multiple stockwork. / Censi, Paolo; Ruberti; Castorina; Comin-Chiaramonti, Piero; Andrade; Gomes, Celso; Antonini.

In: Journal of South American Earth Sciences, Vol. 15, 2002, pag. 215-228.

Risultato della ricerca: Article

Censi, P, Ruberti, Castorina, Comin-Chiaramonti, P, Andrade, Gomes, C & Antonini 2002, 'The geochemistry of the Barra do Itapirapuã carbonatite (Ponta Grossa Arch, Brazil): A multiple stockwork', Journal of South American Earth Sciences, vol. 15, pagg. 215-228.
Censi, Paolo ; Ruberti ; Castorina ; Comin-Chiaramonti, Piero ; Andrade ; Gomes, Celso ; Antonini. / The geochemistry of the Barra do Itapirapuã carbonatite (Ponta Grossa Arch, Brazil): A multiple stockwork. In: Journal of South American Earth Sciences. 2002 ; Vol. 15. pagg. 215-228.
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abstract = "The Early Cretaceous Barra do Itapirapuā carbonatite, in southern Brazil, belongs to the initial stages of the alkaline carbonatitic magmatism in the Ponta Grossa Arch Province, as related to the opening of the south Atlantic Ocean. The magmatic evolution of the complex comprises four phases of intrusive carbonatite that are composed of medium- to coarse-grained Mg and Fe carbonatites with small volumes of late fine- to very fine-grained Mg carbonatites and show evidence of pervasive hydrothermal events. Drill core samples reveal the existence of silicate rocks of syenitic composition of two different origins. Among the silicate rocks, there are syenites of a likely magmatic origin, as well as fenites derived from the granitic protolith, which constitutes the wall rock of the complex. Fenitization around the Barra do Itapirapuā complex is mainly potassic, and fenites are Ca- and LOI-enriched in comparison with the magmatic syenites. Furthermore, the two types of silicate rocks differ in terms of REE and other trace elements. Associated syenites and carbonatites have similar Sr-Nd isotopic compositions, close to the Bulk Earth at 120 Ma. Mixing curves indicate that the carbonatite-syenite association may be accounted for by assimilation of up to 20{\%} crustal material, whereas the late carbonatite composition is consistent with less than 10{\%} assimilation of crustal rocks. An origin by liquid immiscibility for the carbonatite-syenite association can be considered, followed by magmatic differentiation through fractional crystallization of calcite and dolomite in the carbonatite magma. C-O stable isotopic data indicate further reequilibration under hydrothermal conditions at temperatures between 375 and 80 °C. {\circledC} 2002 Elsevier Science Ltd. All rights reserved.",
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T1 - The geochemistry of the Barra do Itapirapuã carbonatite (Ponta Grossa Arch, Brazil): A multiple stockwork

AU - Censi, Paolo

AU - Ruberti, null

AU - Castorina, null

AU - Comin-Chiaramonti, Piero

AU - Andrade, null

AU - Gomes, Celso

AU - Antonini, null

PY - 2002

Y1 - 2002

N2 - The Early Cretaceous Barra do Itapirapuā carbonatite, in southern Brazil, belongs to the initial stages of the alkaline carbonatitic magmatism in the Ponta Grossa Arch Province, as related to the opening of the south Atlantic Ocean. The magmatic evolution of the complex comprises four phases of intrusive carbonatite that are composed of medium- to coarse-grained Mg and Fe carbonatites with small volumes of late fine- to very fine-grained Mg carbonatites and show evidence of pervasive hydrothermal events. Drill core samples reveal the existence of silicate rocks of syenitic composition of two different origins. Among the silicate rocks, there are syenites of a likely magmatic origin, as well as fenites derived from the granitic protolith, which constitutes the wall rock of the complex. Fenitization around the Barra do Itapirapuā complex is mainly potassic, and fenites are Ca- and LOI-enriched in comparison with the magmatic syenites. Furthermore, the two types of silicate rocks differ in terms of REE and other trace elements. Associated syenites and carbonatites have similar Sr-Nd isotopic compositions, close to the Bulk Earth at 120 Ma. Mixing curves indicate that the carbonatite-syenite association may be accounted for by assimilation of up to 20% crustal material, whereas the late carbonatite composition is consistent with less than 10% assimilation of crustal rocks. An origin by liquid immiscibility for the carbonatite-syenite association can be considered, followed by magmatic differentiation through fractional crystallization of calcite and dolomite in the carbonatite magma. C-O stable isotopic data indicate further reequilibration under hydrothermal conditions at temperatures between 375 and 80 °C. © 2002 Elsevier Science Ltd. All rights reserved.

AB - The Early Cretaceous Barra do Itapirapuā carbonatite, in southern Brazil, belongs to the initial stages of the alkaline carbonatitic magmatism in the Ponta Grossa Arch Province, as related to the opening of the south Atlantic Ocean. The magmatic evolution of the complex comprises four phases of intrusive carbonatite that are composed of medium- to coarse-grained Mg and Fe carbonatites with small volumes of late fine- to very fine-grained Mg carbonatites and show evidence of pervasive hydrothermal events. Drill core samples reveal the existence of silicate rocks of syenitic composition of two different origins. Among the silicate rocks, there are syenites of a likely magmatic origin, as well as fenites derived from the granitic protolith, which constitutes the wall rock of the complex. Fenitization around the Barra do Itapirapuā complex is mainly potassic, and fenites are Ca- and LOI-enriched in comparison with the magmatic syenites. Furthermore, the two types of silicate rocks differ in terms of REE and other trace elements. Associated syenites and carbonatites have similar Sr-Nd isotopic compositions, close to the Bulk Earth at 120 Ma. Mixing curves indicate that the carbonatite-syenite association may be accounted for by assimilation of up to 20% crustal material, whereas the late carbonatite composition is consistent with less than 10% assimilation of crustal rocks. An origin by liquid immiscibility for the carbonatite-syenite association can be considered, followed by magmatic differentiation through fractional crystallization of calcite and dolomite in the carbonatite magma. C-O stable isotopic data indicate further reequilibration under hydrothermal conditions at temperatures between 375 and 80 °C. © 2002 Elsevier Science Ltd. All rights reserved.

KW - Carbonatite; Fenitization; Syenite; Earth-Surface Processes; Geology

UR - http://hdl.handle.net/10447/227610

M3 - Article

VL - 15

SP - 215

EP - 228

JO - Journal of South American Earth Sciences

JF - Journal of South American Earth Sciences

SN - 0895-9811

ER -