Plate Tectonics and Hotspots: The Third Dimension
- 19 June 1992
- journal article
- research article
- Published by American Association for the Advancement of Science (AAAS) in Science
- Vol. 256 (5064), 1645-1651
- https://doi.org/10.1126/science.256.5064.1645
Abstract
High-resolution seismic tomographic models of the upper mantle provide powerful new constraints on theories of plate tectonics and hotspots. Midocean ridges have extremely low seismic velocities to a depth of 100 kilometers. These low velocities imply partial melting. At greater depths, low-velocity and high-velocity anomalies record, respectively, previous positions of migrating ridges and trenches. Extensional, rifting, and hotspot regions have deep (> 200 kilometers) low-velocity anomalies. The upper mantle is characterized by vast domains of high temperature rather than small regions surrounding hotspots; the asthenosphere is not homogeneous or isothermal. Extensive magmatism requires a combination of hot upper mantle and suitable lithospheric conditions. High-velocity regions of the upper 200 kilometers of the mantle correlate with Archean cratons.This publication has 53 references indexed in Scilit:
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