Artículo
Generation of Neogene adakitic-like magmas in the Argentine Puna-Eastern Cordillera transition: the Huachichocana Subvolcanic Complex
Maro, Guadalupe
; Suzaño, Nestor Omar
; Villalba Ulberich, Juan Pablo
; Caffe, Pablo Jorge
; Viramonte, Jose Maria
; Viramonte, Jose German
Fecha de publicación:
05/2023
Editorial:
Springer
Revista:
International Journal of Earth Sciences
ISSN:
1437-3254
e-ISSN:
1437-3262
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
The Huachichocana Subvolcanic Complex (HSC) is one of the easternmost Miocene magmatic complexes from the Central Andes back-arc region. This complex comprises three major sheet-like igneous bodies and contiguous minor intrusions of andesitic to dacitic rocks distinguished by their adakite-like high Sr and Sr/Y values. Based on new detailed data of this system, we explore the genesis of intermediate magmas in the far back-arc region of the Central Andes and complement work on similar rocks from the Eastern Cordillera. We add petrography and mineral chemistry studies and we report new whole rock geochemical and Sr–Nd isotopic data, and a U–Pb zircon age for the HSC. The results suggest that these intrusive rocks were derived from melting of a hydrated mantle source and that the adakite-like composition was acquired through amphibole-dominated fractionation at deep to moderate crustal pressures and by the suppression of early plagioclase crystallization in precursor magmas. The presence of mafic microgranular enclaves is frequent and, along with variations in the composition of phenocrysts and common disequilibrium textures, suggests a significant role of mixing between mafic and intermediate magmas during their ascent and storage in the crust. U–Pb radiometric dating yielded a concordia age of 8.343 ± 0.042 Ma for the andesites of the HSC, coinciding with the period of maximum shortening of the eastern border of the Puna plateau. Nevertheless, this igneous complex is located at the southern margin of the Lípez fault system, a zone of lithospheric weakness that should favor magma emplacement so far east of the trench.
Palabras clave:
ADAKITE
,
ANDESITE
,
CENTRAL ANDES
,
MAFIC ENCLAVE
,
MAGMA MIXING
Archivos asociados
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Identificadores
Colecciones
Articulos(IBIGEO)
Articulos de INST.DE BIO Y GEOCIENCIAS DEL NOA
Articulos de INST.DE BIO Y GEOCIENCIAS DEL NOA
Articulos(INECOA)
Articulos de INSTITUTO DE ECORREGIONES ANDINAS
Articulos de INSTITUTO DE ECORREGIONES ANDINAS
Citación
Maro, Guadalupe; Suzaño, Nestor Omar; Villalba Ulberich, Juan Pablo; Caffe, Pablo Jorge; Viramonte, Jose Maria; et al.; Generation of Neogene adakitic-like magmas in the Argentine Puna-Eastern Cordillera transition: the Huachichocana Subvolcanic Complex; Springer; International Journal of Earth Sciences; 112; 5; 5-2023; 1435-1459
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