Nature of the 650-km seismic discontinuity: implications for mantle dynamics and differentiation
Abstract
Chemical buoyancy relationships during subduction of young, thin oceanic plates cause them to be trapped in a gravitationally stable layer between 600 and 700 km that partly isolates the convective systems of the upper and lower mantle. But when mature, thick plates are subducted, their upper, cool differentiated layers may break through this barrier and become entrained in the convective circulation of the lower mantle. The resultant hybrid convection model provides a promising explanation of the properties of the seismic discontinuity at 650km depth and the geochemical evolution of the mantle.
- Publication:
-
Nature
- Pub Date:
- January 1988
- DOI:
- 10.1038/331131a0
- Bibcode:
- 1988Natur.331..131R
- Keywords:
-
- Earth Mantle;
- Lithosphere;
- Plates (Tectonics);
- Seismology;
- Subduction (Geology);
- Basalt;
- Buoyancy;
- Geochemistry;
- Gravitation;
- Volcanology;
- Geophysics