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Geochemistry of Cenozoic plutonic rocks in the extra-Andean southern Patagonia as evidence for a magmatic arc migration process
- Source :
- Andean geology, Andean geology, Servicio Nacional de Geologia y Mineria, 2021, 48 (3), pp.359. ⟨10.5027/andgeoV48n3-3158⟩, Andean geology, 2021, 48 (3), pp.359-402. ⟨10.5027/andgeov48n3-3158⟩, Andean geology, Servicio Nacional de Geologia y Mineria, 2021, 48 (3), pp.359-402. ⟨10.5027/andgeov48n3-3158⟩
- Publication Year :
- 2021
- Publisher :
- HAL CCSD, 2021.
-
Abstract
- International audience; In this work, we present the results of a petrographic and geochemical study that involves seven Cenozoic plutons located in a NS trending belt in western Patagonia, south of the present Chile Triple-Junction and to the east of the present magmatic arc. Four plutons were studied in the northern end, and three in the southern part of the belt. The petrographic and geochemical characteristics (major and trace element contents, eNdt, 87Sr/86Sr initial ratios), of these plutons are different enough to propose a further classification for them: Only the Monte Balmaceda intrusive complex in the southern end of the belt is alkaline (sensu stricto). The Río de Las Nieves and San Lorenzo plutons in the northern area, and the Torres del Paine intrusive complex, in the southern area have “intra-plate transitional” calc-alkaline affinity. Paso de Las Llaves and Cerro Negro del Ghío plutons in the northern area, and Cerro Donoso pluton in the southern area show “arc transitional” calc-alkaline character. The “transitional” character, together with the pluton’s location, and their regional geological context, can be explained by a Mio-Pliocene eastward arc migration coeval with the beginning of the Chile Rise subduction. A slab flattening hypothesis is favoured to explain the arc-migration, which together with the different length and time of arrival of the Chile Rise segments to the subduction zone, contributed to the heterogeneous geochemistry of the studied plutons.
- Subjects :
- [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics
Subduction
Cenozoic
Stratigraphy
Pluton
Trace element
Geochemistry
[SDU.STU.PE]Sciences of the Universe [physics]/Earth Sciences/Petrography
Paleontology
Geology
Context (language use)
Plutonism
Petrography
Geochemistry and Petrology
Back-arc basin
[SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry
[SDU]Sciences of the Universe [physics]
Patagonia
geochemistry
back-arc
Subjects
Details
- Language :
- English
- ISSN :
- 07187092 and 07187106
- Database :
- OpenAIRE
- Journal :
- Andean geology, Andean geology, Servicio Nacional de Geologia y Mineria, 2021, 48 (3), pp.359. ⟨10.5027/andgeoV48n3-3158⟩, Andean geology, 2021, 48 (3), pp.359-402. ⟨10.5027/andgeov48n3-3158⟩, Andean geology, Servicio Nacional de Geologia y Mineria, 2021, 48 (3), pp.359-402. ⟨10.5027/andgeov48n3-3158⟩
- Accession number :
- edsair.doi.dedup.....90621315dbc4bcea93f3491b76685d2b