Polycyclic scoria cones of the Antofagasta de la Sierra basin, Southern Puna plateau, Argentina

Abstract

Despite a number of published papers focusing on the geodynamic implications of the recent Southern Puna mafic magmatism, there have been fewer studies of the volcanology and stratigraphy of this outstanding volcanism. This paper presents a detailed map of two wellpreserved Quaternary scoria cones showing their complex stratigraphy. Complementary morphometric, morpho-structural, petrographic and geochemical data were used to reconstruct the evolution of both volcanoes. The occurrence of more than one eruption at each volcano was inferred by the recognition of temporal hiatuses using morpho-stratigraphic criteria. The polycyclic nature of both scoria cones could be related to a combination of a high input magma in response to lithospheric delamination, a favourable regional stress field and the interaction of rising magma with pre-existing faults. The youngest eruptions in both volcanoes were complex, with shifts in the eruptive style from violent strombolian to hawaiian/strombolian phases, and probably lasted for a few years. The explosive activity was accompanied by the emission of lava flows from lateral vents. Phreatomagmatic activity was triggered during the waning stages of the eruptions. The occurrence of more than one eruption in a single scoria cone and the changes in the eruptive style during longlasting eruptions are important topics for volcanic hazard assessment in the Southern Puna.

Mantle source heterogeneity in monogenetic basaltic systems: A case study of Eğrikuyu monogenetic field (Central Anatolia, Turkey)

“…Monogenetic basaltic fields are spectacular volcanic landscapes that consist of numerous scoria (or cinder) cones, maars, and related lava flows (e.g., Wood, 1980;Connor and Conway, 2000;Valentine and Gregg, 2008;Kereszturi and Németh, 2012;Németh and Kereszturi, 2015;Smith and Németh, 2017), and they occur in different tectonic settings, including subduction zones (e.g., Trans-Mexican volcanic belt; Luhr et al, 1989) and extensional environments (e.g., Auckland volcanic field; McGee et al, 2013). Source heterogeneity, either in an individual monogenetic volcano (sensu lato) or the entire monogenetic basaltic field with respect to the geographical distribution and size of the eruptive centers, and the temporal evolution of monogenetic fields have been recently reported from different parts of the world (e.g., Shaw et al, 2003;Strong and Wolff, 2003;Brenna et al, 2010;McGee et al, 2013;Rasoazanamparany et al, 2015;Báez et al, 2017). Possible mechanisms proposed to explain this variation are various degrees of crystallization or melting, crystal-melt interaction, multiple components of the mantle source, and ascent dynamics (e.g., Kereszturi and Németh, 2012;McGee et al, 2013;Smith and Németh, 2017).…”

Internal Structure and Hydrothermal Fluid Circulation of Parícutin Volcano, Mexico: Insights Gained From Near‐Surface Geophysics

“…The low‐resistivity values (1,000 to 15,000 Ω·m) (Figure 3a) of this anomaly may correspond to Strombolian fallout deposits with a higher open porosity that allows the preferential pathways for rising hydrothermal fluids from the feeder dyke at depth (heat source) to exit at outgassing fumaroles, accounting for high‐T anomalies at the surface (>90°C) (Figure 2b). Furthermore, normal faults produced by the overburden pressure caused by the pyroclastic deposits atop the cone (e.g., Báez et al, 2016) also serve as pathways for rising fluids, whereas lineaments L1 and L2 represent major structural barriers for fluid circulation.…”

Estilos eruptivos asociados al volcanismo monogenético máfico de la región de Pasto Ventura, Puna Austral, Argentina

“…El volcanismo monogenético máfico se presenta en forma de conos de escoria, flujos de lavas, maares, anillos de tobas (tuff rings) y domos (Maro et al, 2017a). La mayoría de estas estructuras volcánicas tienen edades menores a 3 Ma, incluyendo algunas consideradas holocenas (e.g., Viramonte et al, 1984;Báez et al, 2017), aunque en algunos casos son más antiguas que 7 Ma (Risse et al, 2008). Desde el punto de vista de las relaciones volcano-tectónicas el magmatismo máfico de la Puna Austral se asocia a fallas de rumbo y normales relacionadas con la presencia de una componente extensional N-S en el campo de esfuerzo regional que caracteriza a esta región desde el Mioceno Superior (Viramonte et al, 1984;Allmendinger et al, 1989;Marrett y FIG.…”

“…En la mayoría de los casos los volcanes monogenéticos se forman durante erupciones que pueden durar desde algunos días a decenas de años y comúnmente involucran pequeños volúmenes de magma (<1 km 3 ) relacionados con sistemas de alimentación dispersos y relativamente simples, sin desarrollo de cámaras magmáticas en la corteza superior (Vespermann y Schmincke, 2000;Németh y Kereszturi, 2015). Sin embargo, numerosos trabajos (e.g., Németh y Kereszturi, 2015;Báez et al, 2017) han puesto de manifiesto la existencia de un amplio rango de estructuras volcánicas consideradas como monogenéticas, desde estructuras simples (volcanes monogenéticos sensu stricto) a estructuras formadas por múltiples erupciones separadas por hiatos de tiempo de decenas a miles de años (volcanes monogenéticos policíclicos) y/o con variaciones geoquímicas a lo largo de su evolución (volcanes monogenéticos polimagmáticos). La distribución espacial, tamaño, morfología y estilo eruptivo de los volcanes monogenéticos resultan de una compleja interacción de factores internos relacionados con las características intrínsecas del magma (composición, grado de cristalinidad, viscosidad, contenido de volátiles, etc.)…”

“…1) representado por una serie de agrupaciones o campos volcánicos (clusters) formados por domos, conos de escoria, anillos de tobas y maares. Si bien existen numerosas publicaciones que discuten la petrogénesis de este particular volcanismo de retroarco (Deruelle, 1991;Kay et al, 1994;Guzmán et al, 2006;Risse et al, 2008Risse et al, , 2013Drew et al, 2009;Viramonte et al, 2010;Ducea et al, 2013;Maro, 2015;Murray et al, 2015;Schoenbohm y Carrapa, 2015;Maro et al, 2017b), los estudios enfocados en su volcanología física son escasos (e.g., Russo, 2010;Boltshauser, 2012;Báez et al, 2017). En este sentido, este trabajo presenta una caracterización del volcanismo monogenético máfico de la región de Pasto Ventura (Fig.…”