Pyroclastic Density Currents and the Sedimentation of Ignimbrites: Geological Society Memoir by Michael J. Branney, Peter Kokelaar, B. P. Kokelaar
Publisher: Geological Society of London | Number Of Pages: 130 | Publication Date: 2002-12 | ISBN-10: 1862391246 | PDF | 23 Mb
Pyroclastic density currents are awesome volcanic phenomena that can wreak destruction on a regional scale, and can impact global climate. They deposit ignimbrites, which include vast landscape-modifying sheets with volumes exceeding 1000 km3. This book takes stock of our understanding of pyroclastic density currents, and presents a new conceptual framework for investigating how ignimbrites are deposited. It integrates the results of field-based studies, laboratory experiments and numerical modelling, including work on clastic sedimentology and industrial particle transport. Topics covered include the behaviour of particulate currents, mechanisms of clast support and segregation, interpreting ignimbrite lithofacies and architectures, and future research. The new approach focuses on processes and conditions within the lower flow-boundary zone of a current. Superb diagrams explain many new concepts, while the 95 photographs make an explanatory atlas of deposit types. This is essential reading for workers investigating volcanic hazards, and for anyone wishing to interpret modern or ancient ignimbrites, as well as other catastrophically emplaced sediments.