1-1-1-1-1-1-1-1-1-1-1-1-1-1 From: Ross Pierre-Simon <Pierre-Simon.Ross@xxxxxxx> The following workshop will be held on Saturday 4 and Sunday 5 February 2023 immediately after the IAVCEI assembly in Rotorua: *Towards a standardized method of analyzing juvenile pyroclasts in comparative magma fragmentation studies * Explosive eruptions generate pyroclasts and these are studied in a number of ways to understand eruptive events. The first steps are generally grain size analyses and componentry. The juvenile pyroclasts, especially in the ash range, provide important information on primary fragmentation processes, and the state of the magma both prior to and at the point of fragmentation and quenching. There exists an extensive body of literature on the quantification of juvenile particle shapes, internal textures and surface features spanning several decades, yet a standardized methodology has yet to emerge. This precludes robust comparison between different studies and laboratories. The workshop organizers have published a detailed proposal for a standardized methodology of ash studies for magma fragmentation, within three recent papers in Bull. Volcanol. (vol. 83, article 79; vol. 84, articles 13 and 14). The two-day workshop after IAVCEI in Rotorua will therefore be an opportunity to discuss, and refine, this and any other proposals. The workshop will include: - overview presentations on selected topics, - small group discussions on specific aspects, - plenary discussions, - a summary discussion. We hope that a broad consensus can be reached and that, once published, it becomes the new standard. The community would then be able to accumulate consistent data on juvenile pyroclasts from a range of eruption styles, fragmentation mechanisms, magma compositions, crystallinities and vesicularities. Then statistical analyses can be performed, new â??fragmentation diagramsâ?? can be developed and we may obtain deeper insights into the full panoply of magma-to-pyroclast processes. Fragmentation diagrams would allow different styles of particle-forming eruptions to be distinguished, and perhaps even improve the classification of explosive eruptions. Applying such fragmentation diagrams to the deposits of active volcanoes would help to better understand the explosive record of their eruptive history, and so has hazards assessment implications. Everybody is welcome! Your friendly conveners: P.-S. Ross, T. Dürig, J.D.L. White, L. Gurioli, D. Andronico 1-1-1-1-1-1-1-1-1-1-1-1-1-1 ------------------------------
