Paleomagnetism and rock magnetism as tools for volcanology

Elisa J. Piispa,Julie A. Bowles,Geoffrey A. Lerner,Michael H. Ort

doi:10.1007/s00445-022-01529-9

Abstract

Paleomagnetic and rock magnetic methods for studying volcanoes and their products have been developed since the second half of the twentieth century. These methods have been used to find tephra in sediment cores, date volcanic eruptions and deposits, determine emplacement temperatures of volcanic deposits, and estimate flow directions of dikes, lava flows, and pyroclastic flow deposits. In the twenty-first century, these techniques have steadily improved and expanded, resulting in more probing and precise studies of volcanoes using paleomagnetism. We believe that continual improvement of existing techniques and the increased awareness and interest in paleomagnetic methods should allow more studies to enhance the understanding of volcanic processes.

Highlights

Assemblages of magnetic minerals in volcanic rocks typically record Earth’s magnetic field with high fidelity when they cool to ambient temperatures, making them ideal media for paleomagnetic studies (Brunhes 1906; Nakamura and Kikuchi 1912; Chevallier 1925; Cox and Doell 1960; Tauxe et al 2018)
Paleomagnetic techniques were first used for volcanic studies in the 1950s (Hatherton 1954, Hospers et al 1954, Aramaki and Akimoto 1957), and paleomagnetic and rock magnetic approaches were applied in many ways in volcanology throughout the second half of the twentieth century (Table 1)
The development of PSV dating tools (Pavón-Carrasco et al 2011; Hnatyshin and Kravchinsky 2014) that use Bayesian statistics to compare the results of volcanic samples to the reference curve has allowed recent studies to obtain one or multiple discrete age ranges for a specific result, allowing for more precise dating of historic and prehistoric eruptions (Roperch et al 2015; Yasuda et al 2020)

Summary

Introduction

Assemblages of magnetic minerals in volcanic rocks typically record Earth’s magnetic field with high fidelity when they cool to ambient temperatures, making them ideal media for paleomagnetic studies (Brunhes 1906; Nakamura and Kikuchi 1912; Chevallier 1925; Cox and Doell 1960; Tauxe et al 2018). This record of Earth’s field behavior can be used to place age constraints on volcanic processes, and the composition, grain size, abundance, and orientation. Localized or composite records of field change, called PSV reference curves, were created for a variety of locations worldwide

Method

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