MANTLE PLUMES AND THEIR EFFECT ON THE EARTHS SURFACE - A REVIEW AND SYNTHESIS

Plumes are narrow, low-viscosity conduits in a variable-viscosity flui d, up which buoyant material preferentially rises. The function of the rmal plumes is to carry heat upward, It seems likely that mantle plume s exist, and serve to carry heat from the core upward through the mant le. A starting mantle plume produces a distinctive signature on the su rface of the Earth, consisting of a flood basalt and a chain of progre ssively younger volcanoes terminating at a hotspot that is currently v olcanically active. Plumes have been implicated in continental breakup , mass extinctions and reversals of the geomagnetic field, but evidenc e of these associations is not yet conclusive. (C) 1997 Elsevier Scien ce B.V.