Pacific subduction coeval with the Karoo mantle plume: the Early Jurasssic Subcordilleran belt of northwestern Patagonia

The Early Mesozoic magmatism of southwestern Gondwana is reviewed in the light of new U-Pb SHRIMP zircon ages (181 ± 2 Ma, 181 ± 3 Ma, 185 ± 2 Ma, and 182 ± 2 Ma) that establish an Early Jurassic age for the granites of the Subcordilleran plutonic belt in northwestern Argentine Patagonia. New geoche...

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Detalles Bibliográficos
Autores principales: Rapela, Carlos Washington, Pankhurst, Robert J., Fanning, Christopher, Hervé, Francisco
Formato: Libro Capitulo de libro
Lenguaje:Inglés
Publicado: Geological Society of London 2005
Materias:
Geología
Subcordilleran plutonic belt
Early subduction-related magmatic arc
Gondwana
Patagonia
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/128114
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-128114
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Geología
Subcordilleran plutonic belt
Early subduction-related magmatic arc
Gondwana
Patagonia
spellingShingle Geología
Subcordilleran plutonic belt
Early subduction-related magmatic arc
Gondwana
Patagonia
Rapela, Carlos Washington
Pankhurst, Robert J.
Fanning, Christopher
Hervé, Francisco
Pacific subduction coeval with the Karoo mantle plume: the Early Jurasssic Subcordilleran belt of northwestern Patagonia
topic_facet Geología
Subcordilleran plutonic belt
Early subduction-related magmatic arc
Gondwana
Patagonia
description The Early Mesozoic magmatism of southwestern Gondwana is reviewed in the light of new U-Pb SHRIMP zircon ages (181 ± 2 Ma, 181 ± 3 Ma, 185 ± 2 Ma, and 182 ± 2 Ma) that establish an Early Jurassic age for the granites of the Subcordilleran plutonic belt in northwestern Argentine Patagonia. New geochemical and isotopic data confirm that this belt represents an early subduction-related magmatic arc along the proto-Pacific margin of Gondwana. Thus, subduction was synchronous with the initial phase of Chon Aike rhyolite volcanism ascribed to the thermal effects of the Karoo mantle plume and heralding rifting of this part of the supercontinent. Overall, there is clear evidence that successive episodes of calc-alkaline arc magmatism from Late Triassic times until establishment of the Andean Patagonian batholith in the Late Jurassic involved westerly migration and clockwise rotation of the arc. This indicates a changing geodynamic regime during Gondwana break-up and suggests differential rollback of the subducted slab, with accretion of new crustal material and/or asymmetrical ‘scissor-like’ opening of back-arc basins. This almost certainly entailed dextral displacement of continental domains in Patagonia.
format Libro
Capitulo de libro
author Rapela, Carlos Washington
Pankhurst, Robert J.
Fanning, Christopher
Hervé, Francisco
author_facet Rapela, Carlos Washington
Pankhurst, Robert J.
Fanning, Christopher
Hervé, Francisco
author_sort Rapela, Carlos Washington
title Pacific subduction coeval with the Karoo mantle plume: the Early Jurasssic Subcordilleran belt of northwestern Patagonia
title_short Pacific subduction coeval with the Karoo mantle plume: the Early Jurasssic Subcordilleran belt of northwestern Patagonia
title_full Pacific subduction coeval with the Karoo mantle plume: the Early Jurasssic Subcordilleran belt of northwestern Patagonia
title_fullStr Pacific subduction coeval with the Karoo mantle plume: the Early Jurasssic Subcordilleran belt of northwestern Patagonia
title_full_unstemmed Pacific subduction coeval with the Karoo mantle plume: the Early Jurasssic Subcordilleran belt of northwestern Patagonia
title_sort pacific subduction coeval with the karoo mantle plume: the early jurasssic subcordilleran belt of northwestern patagonia
publisher Geological Society of London
publishDate 2005
url http://sedici.unlp.edu.ar/handle/10915/128114
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AT hervefrancisco pacificsubductioncoevalwiththekaroomantleplumetheearlyjurasssicsubcordilleranbeltofnorthwesternpatagonia
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