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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todo:paper_00223530_v48_n1_p43_Kay2023-10-03T14:31:54Z The somuncura large igneous province in Patagonia: Interaction of a transient mantle thermal anomaly with a subducting slab Kay, S.M. Ardolino, A.A. Gorring, M.L. Ramos, V.A. 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. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00223530_v48_n1_p43_Kay |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
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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 Kay, S.M. Ardolino, A.A. Gorring, M.L. Ramos, V.A. 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. |
| format |
JOUR |
| author |
Kay, S.M. Ardolino, A.A. Gorring, M.L. Ramos, V.A. |
| author_facet |
Kay, S.M. Ardolino, A.A. Gorring, M.L. Ramos, V.A. |
| author_sort |
Kay, S.M. |
| 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 |
| url |
http://hdl.handle.net/20.500.12110/paper_00223530_v48_n1_p43_Kay |
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