The geochemistry of the Barra do Itapirapuã carbonatite (Ponta Grossa Arch, Brazil): A multiple stockwork
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 intr...
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ftunivpalermo:oai:iris.unipa.it:10447/227610 2024-02-11T10:08:37+01:00 The geochemistry of the Barra do Itapirapuã carbonatite (Ponta Grossa Arch, Brazil): A multiple stockwork Ruberti, E. Castorina, F. Comin Chiaramonti, P. Gomes, C. Antonini, P. Andrade, F. CENSI, Paolo Ruberti, E. Castorina, F. Censi, P. Comin-Chiaramonti, P. Gomes, C. Antonini, P. Andrade, F. 2002 http://hdl.handle.net/10447/227610 https://doi.org/10.1016/S0895-9811(02)00031-7 eng eng info:eu-repo/semantics/altIdentifier/wos/WOS:000177045900005 volume:15 issue:2 firstpage:215 lastpage:228 numberofpages:14 journal:JOURNAL OF SOUTH AMERICAN EARTH SCIENCES http://hdl.handle.net/10447/227610 doi:10.1016/S0895-9811(02)00031-7 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-0036074388 info:eu-repo/semantics/closedAccess Carbonatite Fenitization Syenite Earth-Surface Processe Geology info:eu-repo/semantics/article 2002 ftunivpalermo https://doi.org/10.1016/S0895-9811(02)00031-7 2024-01-23T23:27:14Z 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. Article in Journal/Newspaper South Atlantic Ocean IRIS Università degli Studi di Palermo Barra ENVELOPE(-61.417,-61.417,-64.367,-64.367) Journal of South American Earth Sciences 15 2 215 228 |
institution |
Open Polar |
collection |
IRIS Università degli Studi di Palermo |
op_collection_id |
ftunivpalermo |
language |
English |
topic |
Carbonatite Fenitization Syenite Earth-Surface Processe Geology |
spellingShingle |
Carbonatite Fenitization Syenite Earth-Surface Processe Geology Ruberti, E. Castorina, F. Comin Chiaramonti, P. Gomes, C. Antonini, P. Andrade, F. CENSI, Paolo The geochemistry of the Barra do Itapirapuã carbonatite (Ponta Grossa Arch, Brazil): A multiple stockwork |
topic_facet |
Carbonatite Fenitization Syenite Earth-Surface Processe Geology |
description |
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. |
author2 |
Ruberti, E. Castorina, F. Censi, P. Comin-Chiaramonti, P. Gomes, C. Antonini, P. Andrade, F. |
format |
Article in Journal/Newspaper |
author |
Ruberti, E. Castorina, F. Comin Chiaramonti, P. Gomes, C. Antonini, P. Andrade, F. CENSI, Paolo |
author_facet |
Ruberti, E. Castorina, F. Comin Chiaramonti, P. Gomes, C. Antonini, P. Andrade, F. CENSI, Paolo |
author_sort |
Ruberti, E. |
title |
The geochemistry of the Barra do Itapirapuã carbonatite (Ponta Grossa Arch, Brazil): A multiple stockwork |
title_short |
The geochemistry of the Barra do Itapirapuã carbonatite (Ponta Grossa Arch, Brazil): A multiple stockwork |
title_full |
The geochemistry of the Barra do Itapirapuã carbonatite (Ponta Grossa Arch, Brazil): A multiple stockwork |
title_fullStr |
The geochemistry of the Barra do Itapirapuã carbonatite (Ponta Grossa Arch, Brazil): A multiple stockwork |
title_full_unstemmed |
The geochemistry of the Barra do Itapirapuã carbonatite (Ponta Grossa Arch, Brazil): A multiple stockwork |
title_sort |
geochemistry of the barra do itapirapuã carbonatite (ponta grossa arch, brazil): a multiple stockwork |
publishDate |
2002 |
url |
http://hdl.handle.net/10447/227610 https://doi.org/10.1016/S0895-9811(02)00031-7 |
long_lat |
ENVELOPE(-61.417,-61.417,-64.367,-64.367) |
geographic |
Barra |
geographic_facet |
Barra |
genre |
South Atlantic Ocean |
genre_facet |
South Atlantic Ocean |
op_relation |
info:eu-repo/semantics/altIdentifier/wos/WOS:000177045900005 volume:15 issue:2 firstpage:215 lastpage:228 numberofpages:14 journal:JOURNAL OF SOUTH AMERICAN EARTH SCIENCES http://hdl.handle.net/10447/227610 doi:10.1016/S0895-9811(02)00031-7 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-0036074388 |
op_rights |
info:eu-repo/semantics/closedAccess |
op_doi |
https://doi.org/10.1016/S0895-9811(02)00031-7 |
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Journal of South American Earth Sciences |
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15 |
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2 |
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215 |
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228 |
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