The use of palaeomagnetism and rock magnetism to understand volcanic processes: introduction

Abstract: This Special Publication provides a snapshot of our understanding of volcanic pro-cesses through the use of palaeomagnetic and rock magnetic techniques. Here, we provide a context for the book, placing individual chapters within the milieu of previous work, including some magnetic techniques that were not used in the particular studies described herein. Thermo-remanent magnetization is a powerful tool to understand processes related to heating and cooling of rocks, including estimating the temperature of emplacement of pyroclastic deposits, which may allow us to better understand the rates of cooling during eruption and transport. Aniso-tropy of magnetic susceptibility and anisotropy of remanence are used primarily to investigate rock fabrics, and allow the interpretation of flow dynamics in dykes, lava flows and pyroclastic deposits, as well as the location of the eruptive vents. Rock magnetic characteristics can help in the corre-lation of volcanic deposits but also providemeans to date volcanic deposits and to better understand the processes of cooling of the deposits, as the magnetic minerals can change with temperature. In addition, volcanic rocksmay be key recorders of past magnetic fields, allowing a better understand-ing of changes in field intensity and, perhaps, providing clues of how the magnetic field is formed. Over the past several decades, palaeomagnetic an