Metamorphic evolution of the Loma Marcelo skarn within the geotectonic context of the crystalline basement of the Ventania System (Argentina)

This study describes the mineralogical and isotopic changes that carbonate xenoliths experienced under multiple metamorphic events and hydrothermal fluid circulation during the evolution of the Ventania System basement. The high reactivity of carbonate xenoliths allowed the preservation of mineral a...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Ballivián Justiniano, Carlos Alberto, Lajoinie, María Florencia, Recio, Clemente, Sato, Ana María, Stipp Basei, Miguel Angelo, Proenza, Joaquín, Aiglsperger, Thomas, Barrio, Raúl Ernesto de, Curci, Marcela, Lanfranchini, Mabel Elena
Formato: Articulo
Lenguaje:Inglés
Publicado: 2019
Materias:
Ciencias Naturales
carbonate xenoliths
Sierras de Ventania (Buenos Aires, Argentina)
mineral chemistry
LA-ICP-MS U-Pb
stable isotopes
hydrothermal fluids
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/76514
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-76514
record_format dspace
spelling I19-R120-10915-765142024-02-07T19:01:52Z http://sedici.unlp.edu.ar/handle/10915/76514 Metamorphic evolution of the Loma Marcelo skarn within the geotectonic context of the crystalline basement of the Ventania System (Argentina) Ballivián Justiniano, Carlos Alberto Lajoinie, María Florencia Recio, Clemente Sato, Ana María Stipp Basei, Miguel Angelo Proenza, Joaquín Aiglsperger, Thomas Barrio, Raúl Ernesto de Curci, Marcela Lanfranchini, Mabel Elena 2019 2019-06-14T14:16:35Z en Ciencias Naturales carbonate xenoliths Sierras de Ventania (Buenos Aires, Argentina) mineral chemistry LA-ICP-MS U-Pb stable isotopes hydrothermal fluids This study describes the mineralogical and isotopic changes that carbonate xenoliths experienced under multiple metamorphic events and hydrothermal fluid circulation during the evolution of the Ventania System basement. The high reactivity of carbonate xenoliths allowed the preservation of mineral assemblages corresponding to at least three metamorphic events in the resulting Loma Marcelo skarn. The Ventania System basement is composed of Neoproterozoic granites and ignimbrites, Early Cambrian granites, and Middle Cambrian rhyolites. Carbonate xenoliths were incorporated during the intrusion of a calc-alkaline granite with an LA-ICP-MS U-Pb crystallization age of 621.6 ± 2.2 Ma. The intrusion induced pyroxene–hornfels facies metamorphism in the carbonate xenoliths and the associated metasomatism generated calcic and magnesian skarns depending on the protolith composition. Garnet, clinopyroxene, wollastonite, bytownite, and meionite were formed in the calcic skarn (CaS), whereas forsterite and spinel were formed in the magnesian skarn (MgS). Crystallization of Early Cambrian alkaline granites was accompanied by intense hydrothermal activity that was responsible for low temperature (≤300 °C) F-metasomatism in the skarn, as evidenced by the presence of F-rich vesuvianite (CaS) and chondrodite (MgS), among other minerals. Vesuvianite was formed from calc-silicate mineral assemblages of the previous metamorphic event, whereas chondrodite was formed by replacement of forsterite. The low temperature formation of these typical high-grade minerals could be an evidence of mineral formation under disequilibrium conditions favoured by the high reactivity of hydrothermal fluids. Neopalaeozoic basement mylonitization under greenschist facies metamorphism was accompanied by hydrothermal fluid circulation. This event promoted extreme mobility of chemical elements in the basement rocks and epidotization (CaS) and serpentinization (MgS) in the Loma Marcelo skarn. The elongated and boudinaged shape of the skarn bodies, parallel to the mylonitic foliation, is a consequence of dextral shearing that affected the basement rocks. Additionally, almost pure grossular crystallized post-tectonically in the CaS. Carbonates of the Loma Marcelo skarn are depleted in 13C and 18O (δ13CV-PDB = −2.5/−10.1‰; δ18OV-SMOW = +7.3/+14.0‰) relative to carbonate sedimentary rocks. The δ13C and δ18O variations can be attributed to the interaction between large amounts of hydrothermal fluids (W/R = 30–50) and Neoproterozoic carbonate sedimentary rocks. Facultad de Ciencias Naturales y Museo Articulo Articulo http://creativecommons.org/licenses/by-nc-sa/4.0/ Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) application/pdf 56-76
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Ciencias Naturales
carbonate xenoliths
Sierras de Ventania (Buenos Aires, Argentina)
mineral chemistry
LA-ICP-MS U-Pb
stable isotopes
hydrothermal fluids
spellingShingle Ciencias Naturales
carbonate xenoliths
Sierras de Ventania (Buenos Aires, Argentina)
mineral chemistry
LA-ICP-MS U-Pb
stable isotopes
hydrothermal fluids
Ballivián Justiniano, Carlos Alberto
Lajoinie, María Florencia
Recio, Clemente
Sato, Ana María
Stipp Basei, Miguel Angelo
Proenza, Joaquín
Aiglsperger, Thomas
Barrio, Raúl Ernesto de
Curci, Marcela
Lanfranchini, Mabel Elena
Metamorphic evolution of the Loma Marcelo skarn within the geotectonic context of the crystalline basement of the Ventania System (Argentina)
topic_facet Ciencias Naturales
carbonate xenoliths
Sierras de Ventania (Buenos Aires, Argentina)
mineral chemistry
LA-ICP-MS U-Pb
stable isotopes
hydrothermal fluids
description This study describes the mineralogical and isotopic changes that carbonate xenoliths experienced under multiple metamorphic events and hydrothermal fluid circulation during the evolution of the Ventania System basement. The high reactivity of carbonate xenoliths allowed the preservation of mineral assemblages corresponding to at least three metamorphic events in the resulting Loma Marcelo skarn. The Ventania System basement is composed of Neoproterozoic granites and ignimbrites, Early Cambrian granites, and Middle Cambrian rhyolites. Carbonate xenoliths were incorporated during the intrusion of a calc-alkaline granite with an LA-ICP-MS U-Pb crystallization age of 621.6 ± 2.2 Ma. The intrusion induced pyroxene–hornfels facies metamorphism in the carbonate xenoliths and the associated metasomatism generated calcic and magnesian skarns depending on the protolith composition. Garnet, clinopyroxene, wollastonite, bytownite, and meionite were formed in the calcic skarn (CaS), whereas forsterite and spinel were formed in the magnesian skarn (MgS). Crystallization of Early Cambrian alkaline granites was accompanied by intense hydrothermal activity that was responsible for low temperature (≤300 °C) F-metasomatism in the skarn, as evidenced by the presence of F-rich vesuvianite (CaS) and chondrodite (MgS), among other minerals. Vesuvianite was formed from calc-silicate mineral assemblages of the previous metamorphic event, whereas chondrodite was formed by replacement of forsterite. The low temperature formation of these typical high-grade minerals could be an evidence of mineral formation under disequilibrium conditions favoured by the high reactivity of hydrothermal fluids. Neopalaeozoic basement mylonitization under greenschist facies metamorphism was accompanied by hydrothermal fluid circulation. This event promoted extreme mobility of chemical elements in the basement rocks and epidotization (CaS) and serpentinization (MgS) in the Loma Marcelo skarn. The elongated and boudinaged shape of the skarn bodies, parallel to the mylonitic foliation, is a consequence of dextral shearing that affected the basement rocks. Additionally, almost pure grossular crystallized post-tectonically in the CaS. Carbonates of the Loma Marcelo skarn are depleted in 13C and 18O (δ13CV-PDB = −2.5/−10.1‰; δ18OV-SMOW = +7.3/+14.0‰) relative to carbonate sedimentary rocks. The δ13C and δ18O variations can be attributed to the interaction between large amounts of hydrothermal fluids (W/R = 30–50) and Neoproterozoic carbonate sedimentary rocks.
format Articulo
Articulo
author Ballivián Justiniano, Carlos Alberto
Lajoinie, María Florencia
Recio, Clemente
Sato, Ana María
Stipp Basei, Miguel Angelo
Proenza, Joaquín
Aiglsperger, Thomas
Barrio, Raúl Ernesto de
Curci, Marcela
Lanfranchini, Mabel Elena
author_facet Ballivián Justiniano, Carlos Alberto
Lajoinie, María Florencia
Recio, Clemente
Sato, Ana María
Stipp Basei, Miguel Angelo
Proenza, Joaquín
Aiglsperger, Thomas
Barrio, Raúl Ernesto de
Curci, Marcela
Lanfranchini, Mabel Elena
author_sort Ballivián Justiniano, Carlos Alberto
title Metamorphic evolution of the Loma Marcelo skarn within the geotectonic context of the crystalline basement of the Ventania System (Argentina)
title_short Metamorphic evolution of the Loma Marcelo skarn within the geotectonic context of the crystalline basement of the Ventania System (Argentina)
title_full Metamorphic evolution of the Loma Marcelo skarn within the geotectonic context of the crystalline basement of the Ventania System (Argentina)
title_fullStr Metamorphic evolution of the Loma Marcelo skarn within the geotectonic context of the crystalline basement of the Ventania System (Argentina)
title_full_unstemmed Metamorphic evolution of the Loma Marcelo skarn within the geotectonic context of the crystalline basement of the Ventania System (Argentina)
title_sort metamorphic evolution of the loma marcelo skarn within the geotectonic context of the crystalline basement of the ventania system (argentina)
publishDate 2019
url http://sedici.unlp.edu.ar/handle/10915/76514
work_keys_str_mv AT ballivianjustinianocarlosalberto metamorphicevolutionofthelomamarceloskarnwithinthegeotectoniccontextofthecrystallinebasementoftheventaniasystemargentina
AT lajoiniemariaflorencia metamorphicevolutionofthelomamarceloskarnwithinthegeotectoniccontextofthecrystallinebasementoftheventaniasystemargentina
AT recioclemente metamorphicevolutionofthelomamarceloskarnwithinthegeotectoniccontextofthecrystallinebasementoftheventaniasystemargentina
AT satoanamaria metamorphicevolutionofthelomamarceloskarnwithinthegeotectoniccontextofthecrystallinebasementoftheventaniasystemargentina
AT stippbaseimiguelangelo metamorphicevolutionofthelomamarceloskarnwithinthegeotectoniccontextofthecrystallinebasementoftheventaniasystemargentina
AT proenzajoaquin metamorphicevolutionofthelomamarceloskarnwithinthegeotectoniccontextofthecrystallinebasementoftheventaniasystemargentina
AT aiglspergerthomas metamorphicevolutionofthelomamarceloskarnwithinthegeotectoniccontextofthecrystallinebasementoftheventaniasystemargentina
AT barrioraulernestode metamorphicevolutionofthelomamarceloskarnwithinthegeotectoniccontextofthecrystallinebasementoftheventaniasystemargentina
AT curcimarcela metamorphicevolutionofthelomamarceloskarnwithinthegeotectoniccontextofthecrystallinebasementoftheventaniasystemargentina
AT lanfranchinimabelelena metamorphicevolutionofthelomamarceloskarnwithinthegeotectoniccontextofthecrystallinebasementoftheventaniasystemargentina
_version_ 1807220385593163776

Ejemplares similares