Research output per year
Research output per year
Gregor Weber, Jon Blundy, Jenni Barclay, David M. Pyle, Paul Cole, Holli Frey, Matthew Manon, Bridie V. Davies, Katharine Cashman
Research output: Chapter in Book/Report/Conference proceeding › Chapter (peer-reviewed) › peer-review
The 2020–21 eruption of La Soufrière, St Vincent began with extrusion of a viscous lava dome, which was destroyed upon transition to a major explosive phase. Here we present petrological data to reconstruct the processes leading up to these events. Bulkrock SiO 2 contents range from 52.8 to 55.4 wt%, classifying the lava and the subsequent scoria as basaltic andesite, the latter being slightly more mafic. Macrocrystal chemistry and modes (plag–cpx–opx–tmt–ol) and crystallinity (45–50 vol%) are largely identical for both phases of the eruption. Pyroxenes are homogenous and precipitated mostly from andesitic melts. Conversely, plagioclase shows strong normal zonation resulting from magma ascent and stalling at multiple crustal levels. Clinopyroxene thermobarometry reveals that crystallization predominantly took place between 8 and 13 km depth at temperatures of 997 +18 −35 ◦ C. A lack of evidence for mafic recharge and changes in volatile content and the omnipresence of xenoliths, suggests pre-eruptive destabilization of an andesitic–dacitic melt pocket that disrupted and entrained antecedent mush. Olivine diffusion profiles show that this interaction preceded the onset of eruption. Low dissolved sulfur contents (≤270 ppm S) place constraints on the total SO 2 gas release. Meltmush disruption appears to be a dominant driver of eruptions at La Soufrière.
Original language | English |
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Title of host publication | The 2020-21 Eruption of La Soufrière Volcano, St Vincent |
Editors | R. E. A. Robertson, E. P. Joseph, J. Barclay, R. S. J. Sparks |
Publisher | Geological Society of London |
Pages | 171-200 |
Number of pages | 30 |
Volume | 539 |
DOIs | |
Publication status | Published - 5 Jan 2024 |
Name | Geological Society Special Publications |
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Research output: Chapter in Book/Report/Conference proceeding › Chapter (peer-reviewed) › peer-review
Research output: Chapter in Book/Report/Conference proceeding › Chapter (peer-reviewed) › peer-review