Crystallisation in basaltic magmas revealed via in situ 4D synchrotron X-ray microtomography

Crystallisation in basaltic magmas revealed via in situ 4D synchrotron X-ray microtomography

Authors: Margherita Polacci, Fabio Arzilli, Giuseppe La Spina, Nolwenn Le Gall, Biao Cai, Margaret E Hartley, Danilo Di Genova, Nghia T Vo, Sara Nonni, Robert C Atwood, Edward W Llewellin, Peter D Lee, Mike R Burton

Journal: Scientific Reports

Publication Date: 30 May, 2018

Department of: Earth and Environmental Sciences, Materials

In Abstract

Watching crystals grow in erupting magmas

Magma crystallisation is a fundamental process driving volcanic eruptions and controlling the style of eruptive activity. Researchers at the University of Manchester and their collaborators have used a new ground-breaking in-situ three-dimensional (3D) imaging and time-dependent experimental approach (known as a ”4D” technique), to visualise the nucleation and growth of crystals in magmas at temperatures of 1200 degrees celsius. This approach offers orders-of-magnitude faster experiments than conventional petrological ex-situ quench experiments, opening an entirely new frontier in experimental petrology and volcanological research. The researchers used the new 4D technique to measure the nucleation and growth kinetics of crystals in experiments which simulate a natural lava flow, helping to improve our understanding of these flows. The experiments were conducted at Diamond Light Source, the UK synchrotron, using a bespoke high-temperature environmental cell with a beamline capable of fast X-ray microtomography. This study provides the first realistic constraint on the timescales of magmatic crystal nucleation and growth and therefore the flow behaviour of basaltic lava flows. The research is a major milestone for experimental petrologists and volcanologists working with lava flow and magma ascent models, and helps in assessing volcanic eruption hazard and in mitigating the risk of eruptions.

X-ray computed microtomography is a high-resolution, non-destructive technique that allows scientists to reconstruct and visualise the internal structure of objects directly in 3D
In situ 4D X-ray microtomography allows us to watch a time-series of experiments as natural features such as crystals and vesicles develop in a magma in 3D in real time
Crystal abundance affects rheological properties of natural magmas: crystal-rich magmas are more viscous and flow more slowly than magmas containing fewer crystals
Less viscous, fast-moving basaltic magmas are very dangerous in terms of volcanic hazard because they are unpredictable as they may cover long distances in only a few hours, threatening people and infrastructures

To read the full article, click here - https://www.nature.com/articles/s41598-018-26644-6

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Footnotes

This research was supported by the RCUK NERC DisEqm project (NE/N018575/1) and project NE/M013561/1.