Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published October 15, 2015 | Accepted Version
Book Section - Chapter Open

The significance of seismic wavespeed minima and thermal maxima in the mantle and the role of dynamic melting

Abstract

It is widely assumed that the boundary layer above the core is the source of intraplate volcanoes such as Hawaii, Samoa, and Yellowstone, and that the sub-plate boundary layer at the top of the mantle is thin and entirely subsolidus. In fact, this upper layer is thicker and has higher expansivity, buoyancy, and insulating power than the lower one, and may have higher potential temperatures. The observed seismic structure of the low-velocity zone (LVZ) including attenuation, anisotropy, sharp boundaries, and a reduction of both compressional and shear moduli can be taken as strong evidence for the ubiquitous presence of melt in the upper mantle. If the LVZ contains as little as 1%–2% melt, then it is the most plausible and accessible source for midplate magmas; deeply rooted active upwellings are unnecessary. The upper boundary layer is also the most plausible source of ancient isotopic signatures of these magmas and their inclusions.

Additional Information

© 2015 Geological Society of America. Accepted 24 February 2015. First published on September 4, 2015.

Attached Files

Accepted Version - Sammis_Accepted.pdf

Files

Sammis_Accepted.pdf
Files (958.3 kB)
Name Size Download all
md5:b064b46c9528d91311a8a9a9387edf0d
958.3 kB Preview Download

Additional details

Created:
August 20, 2023
Modified:
January 13, 2024