Illustrations of models explaining the origin of volcanic chains

This page provides links to diagrams illustrating models explaining the origin of chains of volcanoes, of which the Hawaii-Emperor chain is the most well known.


Bottom-up models: Models with localized sources of magma:

      The traditional hotspot model with a mantle plume.

      A model with a fertile mantle blob from which magma is derived.


Bottom-up-and-top-down models: Models with a localized source accessed by a lithospheric crack:

      A hotspot model with a fertile blob over which a propagating crack is dragged.


Top-down models: Models with a diffuse source tapped by a lithospheric crack:

      A propagating-crack model without a localized magma source.

      A non-propagating-crack model without a localized magma source.

      The edge-driven convection model.


Related resources on the Web(not generated by Railsback):
The page.
      The Mantleplumes page's Edge-driven Convection page by Scott D. King.
A paper on fertile blobs (pdf) by Erin K. Beutel and Don Anderson.
Maps of hotspots:
      Three maps from Anderson and Schramm, in Plates, Plumes, and Paradigms.
      An adaptation of the Duncan and Richards (1991) map.

The six diagrams listed above were drafted by Dr. Bruce Railsback for basic geology classes at the University of Georgia and in the University of New Orleans-Innsbruck summer program. Railsback is not an igneous petrologist or mantle dynamicist. Persons who believe other models could or should be included here should send an email message to Bruce Railsback (

Educators are welcome to use these documents in their teaching, so long as the images are not reproduced in publications and are not used for financial gain. For use in publications or on other websites, send an email message to Bruce Railsback (

These diagrams are part of a much larger collection of geological diagrams drafted by Bruce Railsback for his classes.

Email to Railsback (
Railsback's main web page
UGA Geology Department web page