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

DOI: 10.1038/s41598-018-26644-6

Authors: M. Polacci (University of Manchester) , F. Arzilli (University of Manchester) , G. La Spina (University of Manchester) , N. Le Gall (University of Manchester) , B. Cai (University of Manchester) , M. E. Hartley (University of Manchester) , D. Di Genova (University of Bristol) , Nghia Vo (Diamond Light Source) , S. Nonni (University of Manchester Harwell Campus) , R. C. Atwood (Diamond Light Source) , E. W. Llewellin (Durham University) , P. D. Lee (University of Manchester) , M. R. Burton (University of Manchester)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Scientific Reports , VOL 8

State: Published (Approved)
Published: May 2018
Diamond Proposal Number(s): 12392 , 16188

Abstract: Magma crystallisation is a fundamental process driving eruptions and controlling the style of volcanic activity. Crystal nucleation delay, heterogeneous and homogeneous nucleation and crystal growth are all time-dependent processes, however, there is a paucity of real-time experimental data on crystal nucleation and growth kinetics, particularly at the beginning of crystallisation when conditions are far from equilibrium. Here, we reveal the first in situ 3D time-dependent observations of crystal nucleation and growth kinetics in a natural magma, reproducing the crystallisation occurring in real-time during a lava flow, by combining a bespoke high-temperature environmental cell with fast synchrotron X-ray microtomography. We find that both crystal nucleation and growth occur in pulses, with the first crystallisation wave producing a relatively low volume fraction of crystals and hence negligible influence on magma viscosity. This result explains why some lava flows cover kilometres in a few hours from eruption inception, highlighting the hazard posed by fast-moving lava flows. We use our observations to quantify disequilibrium crystallisation in basaltic magmas using an empirical model. Our results demonstrate the potential of in situ 3D time-dependent experiments and have fundamental implications for the rheological evolution of basaltic lava flows, aiding flow modelling, eruption forecasting and hazard management.

Journal Keywords: Petrology; Volcanology

Diamond Keywords: Volcanology

Subject Areas: Earth Science


Instruments: I12-JEEP: Joint Engineering, Environmental and Processing

Added On: 31/05/2018 08:50

Documents:
s41598-018-26644-6.pdf

Discipline Tags:

Earth Sciences & Environment Natural disaster Geology Geochemistry

Technical Tags:

Imaging Tomography