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Archaeomagnetism |
Department of Geological Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, UK
The basic principles of palaeomagnetism can be stated straightforwardly as follows. A rock unit can acquire magnetization components at various stages in its history, from the time of its formation until the present day. Each component can record the direction of the ambient geomagnetic field at the location of the rock unit at the time of magnetization. Under ideal conditions, the direction and intensity of each of these magnetic components can be determined by laboratory study, and their relative ages and relationships to geological events established. The inclination (dip) of each magnetization component is related directly to the geographic latitude of the rock at the time of magnetization, whereas the declination (azimuth) of the magnetic vector indicates the subsequent rotation of the rock unit with respect to geographic north. Hence, information on latitudinal and rotational movements of the rock unit can be derived. This underlying simplicity is, of course, complicated by a host of factors affecting the magnetization recorded by a rock, and by a wide range of experimental procedures and difficulties. These give rise to a complex terminology, which can make extraction of geologically useful information from a palaeomagnetic study difficult for the non-specialist. The papers in this volume are necessarily full of technical palaeomagnetic and rock magnetic terms. This glossary aims to provide a reference point for readers who are not familiar with detailed palaeomagnetic practice, but who would like to know more about the concepts behind the subject. It will hopefully increase the usefulness of both this
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This 250-word extract was created in the absence of an abstract.
