Features That Favor the Prediction of the Emplacement Location of Maar Volcanoes: A Case Study in the Central Andes, Northern Chile

Abstract

Maar volcanoes are monogenetic landforms whose craters cut below the pre-eruptive surface and are surrounded by a tephra ring. Both the maar crater and the surrounding tephra rim deposits are typically formed due to magma–water explosive interactions. Northern Chile is located in the Central Volcanic Zone of the Andes where, in literature, 14 maars have been recognized as parasite (6) and individual (8) volcanoes. Amongst these individual maars, 3 of them, namely the Tilocálar Sur, Cerro Tujle, and Cerro Overo volcanoes, are not related to calderas and were emplaced <1 Ma ago by magmatic explosive-effusive and phreatomagmatic eruptions. Based on the evolution and control of the volcanic eruptive styles of these three maars, which have been determined in previous research through fieldwork, stratigraphic, morphometric, textural (density and vesicularity), petrographic, and geochemical analyses, a set of key features that favor a prediction of the emplacement location of maar volcanoes in Central Andes, northern Chile are proposed. The set of features that permit and favor the growth mechanisms for maar formations corresponds to (i) a compressive tectonic setting (e.g., ridge structures), (ii) groundwater recharge (e.g., snowmelt and seasonal rainfall), (iii) the lithological setting (e.g., layers of low permeability), (iv) the presence of aquifer and/or endorheic basins (e.g., lakes or salars), and (v) a period of stress relaxation that permits magma ascent to the surface in volcanically active areas. Considering these characteristics, it is possible to identify places where phreatomagmatic eruption can occur. If the magma ascent flux is lower than the groundwater flux, this can lead to a phreatomagmatic eruption because of groundwater coming into contact with the magma. These eruptive features evidence internal—and external—factors that play an essential role in the transition from explosive-effusive magmatic to phreatomagmatic volcanic eruption styles during the same eruptive period that is one of the biggest challenges in volcanic hazard evaluations. Although, in this contribution, a set of features that permit and favor the growth mechanisms for a prediction of the emplacement location of maars in northern Chile is proposed, these considerations could also be applied to identify potential locations in other parts of the world where magma–water interaction eruption could occur. Therefore, this approach could be useful in the prediction of hydromagmatic volcanic eruptions and, thus, in mitigating the impact of volcanic hazard for the inhabitants of the surrounding areas.

Dilemma of Geoconservation of Monogenetic Volcanic Sites under Fast Urbanization and Infrastructure Developments with Special Relevance to the Auckland Volcanic Field, New Zealand

“…While many volcanic fields, particularly Quaternary, display some recognizable patterns in eruption history, an equally large number display ambiguity in spatial and temporal evolution. To overcome this problem, volcanic hazards of such active volcanic fields are often dealt with by analyzing the full eruption spectrum of volcanic eruption types over the life of the volcanic field [40][41][42][43][44][45]. Geoheritage of monogenetic volcanic fields provides an invaluable asset in facilitating geoeducation in resilience to volcanic hazards.…”

The Volcanic Landscapes of the Ancient Hunter-Gatherers of the Atacama Desert Through Their Lithic Remains

“…The Cerro Tujle source is a large quarry-workshop around a small volcanic crater 300 m in diameter and 70 m deep (Figure 7A). It was previously described as a meteorite crater (Ferrando, 1977), but later characterized as a maar-type volcanic crater produced by a phreatic-magmatic eruption (Ureta et al, 2018;Ureta et al, 2020a;Ureta et al, 2020b). The raw material occurs in large blocks and smaller angular fragments of black andesite available around the tephra ring (Figure 7B).…”

Groundwater Chemistry Characterization in the South and Southeast Merapi Volcano, Indonesia

“…As a result, people worldwide tend to use groundwater in the vicinity of a volcanic eruption as the primary water source (UNESCO, 2004;Siebert et al, 2010;Margat & Gun, 2013). According to Demlie et al (2007), Herrera and Custodio (2008), Mulligan et al (2011), and Ureta et al (2020), groundwater around volcanoes is widely used because of its good quality and accessibility.…”