Solid Earth, 6, 553–572, 2015 www.solid-earth.net/6/553/2015/ doi:10.5194/se-6-553-2015 © Author(s) 2015. CC Attribution 3.0 License. Syn-eruptive, soft-sediment deformation of deposits from dilute pyroclastic density current: triggers from granular shear, dynamic pore pressure, ballistic impacts and shock waves G. A. Douillet1, B. Taisne2, È. Tsang-Hin-Sun3, S. K. Müller4, U. Kueppers1, and D. B. Dingwell1 1Earth and Environmental Sciences, Ludwig-Maximilians-Universität, Munich, Germany 2Earth Observatory of Singapore, Nanyang Technological University, Singapore 3Université of Brest and CNRS, Laboratoire Domaines Océaniques, Plouzaré, France 4Meteorological Institute, Ludwig-Maximilians-Universität, Munich, Germany Correspondence to: G. A. Douillet (
[email protected]) Received: 17 November 2014 – Published in Solid Earth Discuss.: 16 December 2014 Revised: 16 April 2015 – Accepted: 20 April 2015 – Published: 21 May 2015 Abstract. Soft-sediment deformation structures can provide to be the signature of shear instabilities occurring at the valuable information about the conditions of parent flows, boundary of two granular media. They may represent the sediment state and the surrounding environment. Here, the frozen record of granular, pseudo Kelvin–Helmholtz examples of soft-sediment deformation in deposits of dilute instabilities. Their recognition can be a diagnostic for pyroclastic density currents are documented and possible flows with a granular basal boundary layer. Vertical syn-eruptive triggers suggested. Outcrops from six different inter-penetration and those folds-and-faults features related volcanoes have been compiled in order to provide a to slumps are driven by their excess weight and occur | downloaded: 11.10.2021 broad perspective on the variety of structures: Soufrière after deposition but penecontemporaneous to the eruption.