Edinburgh Research Explorer

Fluidal pyroclasts reveal the intensity of peralkaline rhyolite pumice cone eruptions

Research output: Contribution to journalArticle

Related Edinburgh Organisations

Open Access permissions

Open

Documents

  • Download as Adobe PDF

    Rights statement: © The Author(s) 2019

    Final published version, 6 MB, PDF-document

    Licence: Creative Commons: Attribution (CC-BY)

https://www.nature.com/articles/s41467-019-09947-8
Original languageEnglish
Article number2010
JournalNature Communications
Volume10
DOIs
StatePublished - 1 May 2019

Abstract

Peralkaline rhyolites are medium to low viscosity, volatile-rich magmas typically associated with rift zones and extensional settings. The dynamics of peralkaline rhyolite eruptions remain elusive with no direct observations recorded, significantly hindering the assessment of hazard and risk. Here we describe uniquely-preserved, fluidal-shaped pyroclasts found within pumice cone deposits at Aluto, a peralkaline rhyolite caldera in the Main Ethiopian Rift. We use a combination of field-observations, geochemistry, X-ray computed microtomography (XCT) and thermal-modelling to investigate how these pyroclasts are formed. We find that they deform during flight and, depending on size, quench prior to deposition or continue to inflate then quench in-situ. These findings reveal important characteristics of the eruptions that gave rise to them: that despite the relatively low viscosity of these magmas, and similarities to basaltic scoria-cone deposits, moderate to intense, unstable, eruption columns are developed; meaning that such eruptions can generate extensive tephra-fall and pyroclastic density currents.

Download statistics

No data available

ID: 82159227