Published by the American Geophysical Union as part of the Geodynamics Series, Volume 1. The focus of the International Geodynamics Project, 1970–1979, was the movements of the surface and upper part of the earth's interior and it was recognized that most of the deformation occurs along narrow belts between the lithospheric plates. Also important to understanding earth process were those motions, primarily vertical that occurred within the plates, remote from plate boundaries. For this reason one of the 10 working groups set up in 1971 was working group 7 with the title "Eperogenic movements of regional extent" under the chairmanship of Dr. J. Tuzo Wilson. In 1974, after Dr. Wilson resigned following his retirement as Principal of Erindale College, University of Toronto, the Bureau of the Inter-Union Commission on Geodynamics appointed Dr. R. I. Walcott as chairman and the name of his working group was changed to "Dynamics of Plate Interiors". The objective of its programme was to determine the nature and origin of the dynamics of the more stable regions of the earth.