The concept of mantle plumes, originally suggested by Morgan (1971), is widely but not unequivocally accepted as the cause for hotspot volcanism. Plumes are thought of as deep-rooted, approximately cylindrical regions of hot rising mantle rock with a typical diameter of 100-200 km. Pressure-release melting near the b- tom of the lithosphere produces magmas that rise to the surface and lead, when the plate moves relative to the plume, to a chain of volcanic edifices whose age p- gresses with increasing distance from the plume. For a long time, the evidence for mantle plumes has been largely...

Terrestrial Magnetism provides a detailed review of all aspects of the main magnetic field of the Earth produced within its core. Topics include the knowledge of geomagnetism coming from paleomagnetic and archeomagnetic data, centuries of terrestrial observations, and more.

The articles in this volume provide a detailed review of all aspects of the main magnetic field of the Earth produced within the Earth's core: its past history, its long and short term changes, the way it is generated. The book contains the combined knowledge of geomagnetism coming from paleomagnetic and archeomagnetic data, centuries of terrestrial observations and from the past few decades of intensive space observations. There is considerable emphasis on the phenomenology and the physical processes of the evolution of the geomagnetic field on different timescales. The book reports fully...