A Textural Perspective on the Magmatic System and Eruptive Behaviour of Merapi Volcano

Abstract
Quantitative textural analysis of crystals, including their number density, shapes, sizes, overall abundance and size distribution can be used to shed light on magmatic processes and the timescales over which they operate. At Merapi, textural analysis of phenocrysts in dome lavas, lava flows, tephra, and in plutonic cumulates has revealed that open system steady state conditions prevail throughout the crustal magma plumbing system over short time periods, with non-steady state conditions prevailing over the longer term. Phenocryst crystallisation likely takes place over tens to hundreds of years prior to eruption. Quantitative textural analysis of feldspar microlites, in conjunction with compositional data, elucidate magma ascent and degassing processes within the conduit during dome forming eruptions, and additionally reveal the driving forces behind transitions between effusive and explosive eruptive behaviour. For example, microlite textures from different stages of the 2010 eruption show that transitions between explosive and effusive activity in 2010 were driven primarily by the dynamics of magma ascent in the shallow conduit.

Citation
Preece, K., van der Zwan, F., Hammer, J., & Gertisser, R. (2023). A Textural Perspective on the Magmatic System and Eruptive Behaviour of Merapi Volcano. Active Volcanoes of the World, 265–289. https://doi.org/10.1007/978-3-031-15040-1_9

Acknowledgements
We gratefully acknowledge our colleagues from the Center of Volcanology and Geological Hazard Mitigation (CVGHM) and from BPPTKG in Yogyakarta for their support of this work in Indonesia. KP and RG extend their special thanks to Biyanto for logistical help in the field. Amelia Bain is thanked for a timely and constructive review, which helped to improve this chapter. This is SOEST publication no. 10992.

Publisher
Springer International Publishing

DOI
10.1007/978-3-031-15040-1_9

Additional Links
https://link.springer.com/10.1007/978-3-031-15040-1_9

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