The Mencué Batholith: Permian episodic arc-related magmatism in the western North Patagonian Massif, Argentina

ABSTRACT

The Mencué Batholith, western North Patagonian Massif, includes three major bodies. The Mencué Granodiorite, Cura Lauquén Granite and La Blancura Syenogranite. There are dikes of granitic and basaltic rocks cutting the above-cited rocks.

The Mencué Batholith represents several episodes of magmatism, with ages varying between 294 and 239 Ma. The Mencué Granodiorite and the Cura Lauquén Granite are solid-state deformed and are S-type. They have high-K and normal calc-alkaline affinities. These rocks contain significant quantities of subduction-zone chemical components that decrease towards younger lithofacies. La Blancura Syenogranite lack subduction zone chemical components and represent A-type granite, typical of within-plate magmatism. The partial melting of metapelites could be the process of formation of these bodies. The older lithofacies of the Mencué Batholith, found westernmost, display a stronger deformation, but there is a progressive eastward change to younger and mildly deformed bodies and even non-deformed bodies. We conclude that the evolution of the Mencué Batholith start in the Sakmarian-Roadian (Early Permian) period. At this time, a subduction zone was active to the west and its thermal influence affected sedimentary or metamorphic rocks producing S-type granites

During the Wordian and Capitanian, (Middle Permian) periods, the Mencué Batholith was mildly deformed, possibly in the process of the vanishing of the deformation and has a minor subduction chemical signature.

Between the Wuchiapingian and Olenekia periods, the alkaline facies of the Mencué Batholith show an absence of deformation and the characteristics of within-plate magmatism.

The Early Permian magmatic events in the western North Patagonian Massif are represented by the older bodies of the Mencué Batholith and were produced by subduction in the western margin of the Gondwanan continent.

The Late Permian-Early Triassic magmatic events show a noticeable decreasing influence of subduction and an increasing influence of within-plate chemical components.

Graphical Abstract

KEYWORDS:

• Mencué Batholith
• Gondwana magmatism
• North Patagonian Massif

Highlights

• Mencué Batholith include the Mencué Granodiorite, Cura Lauquén Granite and La Blancura Syenogranite

• Outcrop in western North Patagonian Massif, with ages between 294 and 250 Ma.

• The Early Permian granites were produced by subduction.

• The Late Permian-Early Triassic ones have within plate chemical components.

Acknowledgments

Many thanks to the Herrera, Arias, Jaramillo, Cortes, Fuensalida, and Quiñenao families and many friends in Cañadones Mencué and La Blancura. Special thanks to Domingo Lasciar and his family in Cañadón Cura Lauquén and the Macaya family of Mencué for their friendship. Our thanks to the family of José Ruiz and Ancatrúz, and the Loncos of the Laguna Blanca and Plang Curá Mapuche communities. The Navarrete, García, Alvarez, Criado, and Contín families of the Comallo, Paso Limay, and Coquelén localities are gratefully acknowledged.

We are deeply grateful for the comments and suggestions made by Dr. J. Otamendi and an anonymous reviewer, which have considerably improved the quality of our manuscript.

The editor is profoundly acknowledged for their review of the manuscript style and language, as well as manuscript handling. We would also like to acknowledge David Gorman, who carefully corrected the previous version of our manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary Material

Supplemented data of this article can be accessed here.

Additional information

Funding

This study forms part of the research projects, ‘Prospección geofísica de la Provincia de Rio Negro’ (grant \), ‘Ciclos tectomagmáticos de la República Argentina’ (grant 24/H060), and Gondwánico y Patagonídico del Macizo Nordpatagónico occidental (grant 24/h121) granted by the Universidad Nacional del Sur, and Análisis de la configuración y evolución geológico–geofísica del sector oriental de la Comarca Nordpatagónica (grant 546), supported by the ANPCYT-UNS (Agencia Nacional de Promoción Científica y Tecnológica), and Significado y evolución de los eventos tectonomagmáticos Gondwánicos y Patagonídicos del norte de Patagonia (grant 11220150100184).