Physicochemical or geochemical

• Horwell, C. J., Hillman, S. E., Cole, P. D., Loughlin, S. C., Llewellin, E. W., Damby, D. E., Christopher, T., (2014), Controls on variations in cristobalite abundance in ash generated by the Soufrière Hills volcano, Montserrat in the period 1997-2010, The Eruption of Soufriere Hills Volcano, Montserrat from 2000 to 2010, Memoir of the Geological Society of London , Geological Society of London, Chapter 21. 39: 399-406, 10.1144/M39.21, Wadge, G. , Robertson, R., Voight, B.