Alternating Subplinian and phreatomagmatic phases during the construction of a phonolitic maar-diatreme volcano (Caldera del Rey, Tenerife, Canary Islands)

Bowers, Oliver; Dávila Harris, Pablo; Winstanley, Rebecca; Wadsworth, Fabian B.; Brown, Richard J.

Abstract

The Early Pleistocene, well exposed, Caldera del Rey maar-diatreme volcano, Tenerife, Canary Islands was constructed during a ∼ VEI 4 phonolitic eruption that involved two cycles of magmatic-to-phreatomagmatic activity and resulted in two overlapping craters aligned NE-SW. Magmatic phases fed unsteady Subplinian eruption columns that reached 8–12 km altitude and dispersed tephra to the west and southwest of the volcano and shed pyroclastic density currents. Phreatomagmatic phases, driven by explosive interactions between magma and groundwater, constructed an extensive tephra ring via deposition from ballistic curtains, pyroclastic density currents, and tephra fall. Near-optimal-scaled depth phreatomagmatic explosions (strong and/or shallow) excavated a substantial diatreme beneath the north crater and constructed a substantial tephra ring. This abruptly transitioned to deeper-than-optimal scaled depth explosions (weak and/or deep) that erupted mostly fine ash which was dispersed by dilute pyroclastic density currents and fallout and filled the south crater. At distances of >4 km from the volcano, over a metre of ash and pumice accumulated during the phreatomagmatic phases. The Caldera del Rey volcano provides an instructive study on how interaction between ascending felsic magma and groundwater can modify Subplinian eruptions.

Citation

Bowers, O., Dávila Harris, P., Winstanley, R., Wadsworth, F. B., & Brown, R. J. (2023). Alternating Subplinian and phreatomagmatic phases during the construction of a phonolitic maar-diatreme volcano (Caldera del Rey, Tenerife, Canary Islands). Journal of Volcanology and Geothermal Research, 443, 107920. https://doi.org/10.1016/j.jvolgeores.2023.107920

• Journal Article Type: Article
• Acceptance Date: Sep 27, 2023
• Online Publication Date: Oct 6, 2023
• Publication Date: 2023-11
• Deposit Date: Nov 2, 2023
• Publicly Available Date: Nov 2, 2023
• Journal: Journal of Volcanology and Geothermal Research
• Print ISSN: 0377-0273
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 443
• Pages: 107920
• DOI: https://doi.org/10.1016/j.jvolgeores.2023.107920
• Keywords: Geochemistry and Petrology; Geophysics
• Public URL: https://durham-repository.worktribe.com/output/1874635