Southern Patagonian plateau basalts and deformation: Backarc testimony of ridge collisions

The distribution and volume of Tertiary Patagonian plateau basalts and the evolution of the Patagonian fold and thrust belt between 46° and 49°S appear to be closely tied with ridge-trench interactions along the continental margin to the west. Eocene plateau basalts south of 43°S are associated with...

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Autores principales: Ramos, V.A., Kay, S.M.
Formato: JOUR
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Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00401951_v205_n1-3_p261_Ramos
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spelling todo:paper_00401951_v205_n1-3_p261_Ramos2023-10-03T14:50:06Z Southern Patagonian plateau basalts and deformation: Backarc testimony of ridge collisions Ramos, V.A. Kay, S.M. basalt fold and thrust belt mantle source ridge/trench interaction slab window Tertiary Argentina, Patagonia The distribution and volume of Tertiary Patagonian plateau basalts and the evolution of the Patagonian fold and thrust belt between 46° and 49°S appear to be closely tied with ridge-trench interactions along the continental margin to the west. Eocene plateau basalts south of 43°S are associated with a gap in the Eocene arc and can be related to a proposed collision of the Aluk-Farallon ridge against the trench at this time. Eruptions of Late Miocene to Recent plateau basalts between 46° and 49°S can be related to time-transgressive slab windows in the underlying mantle generated by the collision of segments of the Chile ridge at 10-14 Ma and 6 Ma. The principal deformation in the Patagonian fold and thrust belt predates the eruption of the basalts and also appears to be related with Late Miocene ridge collision. Comparison of plateau basalts related to the collision of the three distinct ridge segments suggests that the volume of basalt erupted increases with the length of the collided ridge segment. Almost all Eocene to Recent plateau basalts between 46° and 49°S have OIB-like (ocean island basalt) trace element signatures showing that the mantle source region changed little with time. Plateau basalts with more arc-like signatures appear to be contaminated by continental crust. Relative melting percentages inferred from the trace element chemistry of the plateau basalts correlate with volumes of erupted basalt implying spatial and temporal changes in temperatures in the mantle source that can be correlated with slab windows. © 1992. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00401951_v205_n1-3_p261_Ramos
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic basalt
fold and thrust belt
mantle source
ridge/trench interaction
slab window
Tertiary
Argentina, Patagonia
spellingShingle basalt
fold and thrust belt
mantle source
ridge/trench interaction
slab window
Tertiary
Argentina, Patagonia
Ramos, V.A.
Kay, S.M.
Southern Patagonian plateau basalts and deformation: Backarc testimony of ridge collisions
topic_facet basalt
fold and thrust belt
mantle source
ridge/trench interaction
slab window
Tertiary
Argentina, Patagonia
description The distribution and volume of Tertiary Patagonian plateau basalts and the evolution of the Patagonian fold and thrust belt between 46° and 49°S appear to be closely tied with ridge-trench interactions along the continental margin to the west. Eocene plateau basalts south of 43°S are associated with a gap in the Eocene arc and can be related to a proposed collision of the Aluk-Farallon ridge against the trench at this time. Eruptions of Late Miocene to Recent plateau basalts between 46° and 49°S can be related to time-transgressive slab windows in the underlying mantle generated by the collision of segments of the Chile ridge at 10-14 Ma and 6 Ma. The principal deformation in the Patagonian fold and thrust belt predates the eruption of the basalts and also appears to be related with Late Miocene ridge collision. Comparison of plateau basalts related to the collision of the three distinct ridge segments suggests that the volume of basalt erupted increases with the length of the collided ridge segment. Almost all Eocene to Recent plateau basalts between 46° and 49°S have OIB-like (ocean island basalt) trace element signatures showing that the mantle source region changed little with time. Plateau basalts with more arc-like signatures appear to be contaminated by continental crust. Relative melting percentages inferred from the trace element chemistry of the plateau basalts correlate with volumes of erupted basalt implying spatial and temporal changes in temperatures in the mantle source that can be correlated with slab windows. © 1992.
format JOUR
author Ramos, V.A.
Kay, S.M.
author_facet Ramos, V.A.
Kay, S.M.
author_sort Ramos, V.A.
title Southern Patagonian plateau basalts and deformation: Backarc testimony of ridge collisions
title_short Southern Patagonian plateau basalts and deformation: Backarc testimony of ridge collisions
title_full Southern Patagonian plateau basalts and deformation: Backarc testimony of ridge collisions
title_fullStr Southern Patagonian plateau basalts and deformation: Backarc testimony of ridge collisions
title_full_unstemmed Southern Patagonian plateau basalts and deformation: Backarc testimony of ridge collisions
title_sort southern patagonian plateau basalts and deformation: backarc testimony of ridge collisions
url http://hdl.handle.net/20.500.12110/paper_00401951_v205_n1-3_p261_Ramos
work_keys_str_mv AT ramosva southernpatagonianplateaubasaltsanddeformationbackarctestimonyofridgecollisions
AT kaysm southernpatagonianplateaubasaltsanddeformationbackarctestimonyofridgecollisions
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