The somuncura large igneous province in Patagonia: Interaction of a transient mantle thermal anomaly with a subducting slab

The Oligo-Miocene Somuncura province is the largest (∼55 000 km2) back-arc mafic volcanic field in Patagonia, and one of Earth's largest with no clear link to a hotspot or major extension. Major and trace element and Sr-Nd-Pb isotopic data suggest involvement of a plume-like component in the ma...

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Detalles Bibliográficos
Autores principales:	Ardolino, Alberto, Ramos, Victor Alberto
Publicado:	2007
Materias:	Large igneous province (LIP) Patagonia Plume-like upwelling Slab interaction Somuncura plateau crustal contamination large igneous province magma chemistry magmatism mantle source melting trace element South America
Acceso en línea:	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00223530_v48_n1_p43_Kay http://hdl.handle.net/20.500.12110/paper_00223530_v48_n1_p43_Kay
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	paper:paper_00223530_v48_n1_p43_Kay
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spelling	paper:paper_00223530_v48_n1_p43_Kay2023-06-08T14:49:59Z The somuncura large igneous province in Patagonia: Interaction of a transient mantle thermal anomaly with a subducting slab Ardolino, Alberto Ramos, Victor Alberto Large igneous province (LIP) Patagonia Plume-like upwelling Slab interaction Somuncura plateau crustal contamination large igneous province magma chemistry magmatism mantle source melting trace element Patagonia South America The Oligo-Miocene Somuncura province is the largest (∼55 000 km2) back-arc mafic volcanic field in Patagonia, and one of Earth's largest with no clear link to a hotspot or major extension. Major and trace element and Sr-Nd-Pb isotopic data suggest involvement of a plume-like component in the mantle magma source mixed with hydrous, but not high field strength element (HFSE)-depleted components, from a disintegrating subducting plate. Magmatism is attributed to mantle upwelling related to disturbances during plate reorganization, possibly at a time when the South America plate was nearly stationary over the underlying mantle. Melting was enhanced by hydration of the mantle during Paleogene subduction. Crustal contamination was minimal in a refractory crust that had been extensively melted in the Jurassic. Eruption began with low-volume intraplate alkaline mafic flows with depleted Nd-Sr isotopic signatures. These were followed by voluminous ∼29-25 Ma tholeiitic mafic flows with flat light and steep heavy rare earth element (REE) patterns, intraplate-like La/Ta ratios, arc-like Ba/La ratios and enriched Sr-Nd isotopic signatures. Their source can be explained by mixing EM1-Tristan da Cunha-like and depleted mantle components with subduction-related components. Post-plateau ∼24-17 Ma alkaline flows with steep REE patterns, high incompatible element abundances, and depleted Sr-Nd isotopic signatures mark the ebbing of the mantle upwelling. Copyright © 2007 Oxford University Press. Fil:Ardolino, A.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Ramos, V.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2007 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00223530_v48_n1_p43_Kay http://hdl.handle.net/20.500.12110/paper_00223530_v48_n1_p43_Kay
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	Large igneous province (LIP) Patagonia Plume-like upwelling Slab interaction Somuncura plateau crustal contamination large igneous province magma chemistry magmatism mantle source melting trace element Patagonia South America
spellingShingle	Large igneous province (LIP) Patagonia Plume-like upwelling Slab interaction Somuncura plateau crustal contamination large igneous province magma chemistry magmatism mantle source melting trace element Patagonia South America Ardolino, Alberto Ramos, Victor Alberto The somuncura large igneous province in Patagonia: Interaction of a transient mantle thermal anomaly with a subducting slab
topic_facet	Large igneous province (LIP) Patagonia Plume-like upwelling Slab interaction Somuncura plateau crustal contamination large igneous province magma chemistry magmatism mantle source melting trace element Patagonia South America
description	The Oligo-Miocene Somuncura province is the largest (∼55 000 km2) back-arc mafic volcanic field in Patagonia, and one of Earth's largest with no clear link to a hotspot or major extension. Major and trace element and Sr-Nd-Pb isotopic data suggest involvement of a plume-like component in the mantle magma source mixed with hydrous, but not high field strength element (HFSE)-depleted components, from a disintegrating subducting plate. Magmatism is attributed to mantle upwelling related to disturbances during plate reorganization, possibly at a time when the South America plate was nearly stationary over the underlying mantle. Melting was enhanced by hydration of the mantle during Paleogene subduction. Crustal contamination was minimal in a refractory crust that had been extensively melted in the Jurassic. Eruption began with low-volume intraplate alkaline mafic flows with depleted Nd-Sr isotopic signatures. These were followed by voluminous ∼29-25 Ma tholeiitic mafic flows with flat light and steep heavy rare earth element (REE) patterns, intraplate-like La/Ta ratios, arc-like Ba/La ratios and enriched Sr-Nd isotopic signatures. Their source can be explained by mixing EM1-Tristan da Cunha-like and depleted mantle components with subduction-related components. Post-plateau ∼24-17 Ma alkaline flows with steep REE patterns, high incompatible element abundances, and depleted Sr-Nd isotopic signatures mark the ebbing of the mantle upwelling. Copyright © 2007 Oxford University Press.
author	Ardolino, Alberto Ramos, Victor Alberto
author_facet	Ardolino, Alberto Ramos, Victor Alberto
author_sort	Ardolino, Alberto
title	The somuncura large igneous province in Patagonia: Interaction of a transient mantle thermal anomaly with a subducting slab
title_short	The somuncura large igneous province in Patagonia: Interaction of a transient mantle thermal anomaly with a subducting slab
title_full	The somuncura large igneous province in Patagonia: Interaction of a transient mantle thermal anomaly with a subducting slab
title_fullStr	The somuncura large igneous province in Patagonia: Interaction of a transient mantle thermal anomaly with a subducting slab
title_full_unstemmed	The somuncura large igneous province in Patagonia: Interaction of a transient mantle thermal anomaly with a subducting slab
title_sort	somuncura large igneous province in patagonia: interaction of a transient mantle thermal anomaly with a subducting slab
publishDate	2007
url	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00223530_v48_n1_p43_Kay http://hdl.handle.net/20.500.12110/paper_00223530_v48_n1_p43_Kay
work_keys_str_mv	AT ardolinoalberto thesomuncuralargeigneousprovinceinpatagoniainteractionofatransientmantlethermalanomalywithasubductingslab AT ramosvictoralberto thesomuncuralargeigneousprovinceinpatagoniainteractionofatransientmantlethermalanomalywithasubductingslab AT ardolinoalberto somuncuralargeigneousprovinceinpatagoniainteractionofatransientmantlethermalanomalywithasubductingslab AT ramosvictoralberto somuncuralargeigneousprovinceinpatagoniainteractionofatransientmantlethermalanomalywithasubductingslab
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The somuncura large igneous province in Patagonia: Interaction of a transient mantle thermal anomaly with a subducting slab

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