Geochemical variations in Cenozoic back-arc basalts at the border of La Pampa and Mendoza provinces, Argentina

Back-arc volcanism was active in central-western Argentina (provinces of Mendoza and La Pampa) from the Miocene through historic times. The rocks of 39 monogenetic volcanoes located in this area were studied in order to define their geochemical characteristics. The dominant rock texture is porphyrit...

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Detalles Bibliográficos
Autores principales: Bertotto, Gustavo Walter, Cingolani, Carlos Alberto, Bjerg, Ernesto A.
Formato: Articulo
Lenguaje:Inglés
Publicado: 2009
Materias:
Geología
Basalts
Back-arc
Geochemistry
Central-western Argentina
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/152051
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-152051
record_format dspace
spelling I19-R120-10915-1520512023-04-24T20:08:43Z http://sedici.unlp.edu.ar/handle/10915/152051 issn:0895-9811 Geochemical variations in Cenozoic back-arc basalts at the border of La Pampa and Mendoza provinces, Argentina Bertotto, Gustavo Walter Cingolani, Carlos Alberto Bjerg, Ernesto A. 2009 2023-04-24T18:49:11Z en Geología Basalts Back-arc Geochemistry Central-western Argentina Back-arc volcanism was active in central-western Argentina (provinces of Mendoza and La Pampa) from the Miocene through historic times. The rocks of 39 monogenetic volcanoes located in this area were studied in order to define their geochemical characteristics. The dominant rock texture is porphyritic, with intergranular, pilotaxitic and hyalophitic groundmasses. The most frequent phenocrysts are olivine followed by olivine–plagioclase–clinopyroxene. Their SiO2 content varies between 42.3 and 51.2 wt.%, the most abundant rocks are trachybasalts, followed by basalts and basanites, all of them alkaline. The rocks display enrichment of incompatible elements that varies according to the geographic location and age. There is an increase in incompatible element concentrations from the southern and central to the northern zones. Also, in the northern part of the study area, the behavior of incompatible elements varies with time; the incompatible element ratios of the Plio–Pleistocene rocks show arc signature, while the rocks of the Miocene De la Laguna volcano show intraplate affinity. We conclude for this sector that the mantle source region was modified after the generation of Miocene magmas by subduction-related fluids. These fluids are related to a late Miocene episode of subhorizontal subduction, i.e., after the generation of the rocks of De la Laguna volcano. Centro de Investigaciones Geológicas Consejo Nacional de Investigaciones Científicas y Técnicas Universidad Nacional del Sur Articulo Articulo http://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International (CC BY 4.0) application/pdf 360-373
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Geología
Basalts
Back-arc
Geochemistry
Central-western Argentina
spellingShingle Geología
Basalts
Back-arc
Geochemistry
Central-western Argentina
Bertotto, Gustavo Walter
Cingolani, Carlos Alberto
Bjerg, Ernesto A.
Geochemical variations in Cenozoic back-arc basalts at the border of La Pampa and Mendoza provinces, Argentina
topic_facet Geología
Basalts
Back-arc
Geochemistry
Central-western Argentina
description Back-arc volcanism was active in central-western Argentina (provinces of Mendoza and La Pampa) from the Miocene through historic times. The rocks of 39 monogenetic volcanoes located in this area were studied in order to define their geochemical characteristics. The dominant rock texture is porphyritic, with intergranular, pilotaxitic and hyalophitic groundmasses. The most frequent phenocrysts are olivine followed by olivine–plagioclase–clinopyroxene. Their SiO2 content varies between 42.3 and 51.2 wt.%, the most abundant rocks are trachybasalts, followed by basalts and basanites, all of them alkaline. The rocks display enrichment of incompatible elements that varies according to the geographic location and age. There is an increase in incompatible element concentrations from the southern and central to the northern zones. Also, in the northern part of the study area, the behavior of incompatible elements varies with time; the incompatible element ratios of the Plio–Pleistocene rocks show arc signature, while the rocks of the Miocene De la Laguna volcano show intraplate affinity. We conclude for this sector that the mantle source region was modified after the generation of Miocene magmas by subduction-related fluids. These fluids are related to a late Miocene episode of subhorizontal subduction, i.e., after the generation of the rocks of De la Laguna volcano.
format Articulo
Articulo
author Bertotto, Gustavo Walter
Cingolani, Carlos Alberto
Bjerg, Ernesto A.
author_facet Bertotto, Gustavo Walter
Cingolani, Carlos Alberto
Bjerg, Ernesto A.
author_sort Bertotto, Gustavo Walter
title Geochemical variations in Cenozoic back-arc basalts at the border of La Pampa and Mendoza provinces, Argentina
title_short Geochemical variations in Cenozoic back-arc basalts at the border of La Pampa and Mendoza provinces, Argentina
title_full Geochemical variations in Cenozoic back-arc basalts at the border of La Pampa and Mendoza provinces, Argentina
title_fullStr Geochemical variations in Cenozoic back-arc basalts at the border of La Pampa and Mendoza provinces, Argentina
title_full_unstemmed Geochemical variations in Cenozoic back-arc basalts at the border of La Pampa and Mendoza provinces, Argentina
title_sort geochemical variations in cenozoic back-arc basalts at the border of la pampa and mendoza provinces, argentina
publishDate 2009
url http://sedici.unlp.edu.ar/handle/10915/152051
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AT bjergernestoa geochemicalvariationsincenozoicbackarcbasaltsattheborderoflapampaandmendozaprovincesargentina
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