High precision U/Pb zircon dating of the Chalten Plutonic Complex (Cerro Fitz Roy, Patagonia) and its relationship to arc migration in the southernmost Andes

Détails

ID Serval
serval:BIB_EF5A1B9C9322
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
High precision U/Pb zircon dating of the Chalten Plutonic Complex (Cerro Fitz Roy, Patagonia) and its relationship to arc migration in the southernmost Andes
Périodique
Tectonics
Auteur(s)
Ramirez de Arellano C., Putlitz B., Muntener O., Ovtcharova M.
ISSN-L
0278-7407
Statut éditorial
Publié
Date de publication
2012
Peer-reviewed
Oui
Volume
31
Pages
TC4009
Langue
anglais
Résumé
We report new high-precision U/Pb ages and geochemical data from the
Chalten Plutonic Complex to better understand the link between magmatism
and tectonics in Southern Patagonia. This small intrusion located in the
back-arc region east of the Patagonian Batholith provides important
insights on the role of arc migration and subduction erosion. The
Chalten Plutonic Complex consists of a suite of calc-alkaline gabbroic
to granitic rocks, which were emplaced over 530 kyr between 16.90 +/-
0.05 Ma and 16.37 +/- 0.02 Ma. A synthesis of age and geochemical data
from other intrusions in Patagonia reveals (a) striking similarities
between the Chalten Plutonic Complex and the Neogene intrusions of the
batholith and differences to other back-arc intrusions such as Torres
del Paine (b) a distinct E-W trend of calc-alkaline magmatic activity
between 20 and 17 Ma. We propose that this trend reflects the eastward
migration of the magmatic arc, and the consistent age pattern between
the subduction segments north and south of the Chile triple junction
suggests a causal relation with a period of fast subduction of the
Farallon-Nazca plate during the Early Miocene. Previously proposed flat
slab models are not consistent with the present location and morphology
of the Southern Patagonian Batholith. We advocate, alternatively, that
migration of the magmatic arc is caused by subduction erosion due to the
increasing subduction velocities during the Early Miocene.
Création de la notice
24/09/2012 20:08
Dernière modification de la notice
03/03/2018 22:34
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