This symposium on Earth expansion was made possible through the help of Ken Richards and John Davidson of Esso Australia and John Elliston of Peko Wallsend, who organized the financial support of oil and mining companies, and of Professor Graeme Philip, Chairman of the Earth Resources Foundation, which hosted the meeting.

Organization, editing, and preparation of camera-ready copy was solely the responsibility of the convener. Refereeing proved difficult for it was found that plate-tectonics supporters tended to reject as naive, arguments supporting expansion, and vice versa. Hence I decided that opinions and interpretations should stand without screening, for after all, such is the purpose of a symposium. At the outset I took pains to emphasize that contributors denying or criticizing Earth expansion would be welcomed. In the preparation of this volume, no paper or statement contrary to Earth expansion was in any way suppressed or reduced.

The format was changed from the octavo originally contemplated to A4 because many of the maps and diagrams submitted would not reproduce satisfactorily on the smaller page.  The papers have been grouped so that discussion of related topics fall together, but of course several range broadly and could have been differently grouped.

The historical introduction (Carey, Brunschweiler, Vogel) sets the background of the evolution of beliefs about the Earth through the millennia and the century, and the attempts to reconstruct the Archean Earth.   Expansion models for the last two hundred million years can be directly related to present configurations, and hence differ in method from Precambrian models. Contributions by Owen, Dooley, Bailey & Stewart, Richard, and Vogel & Schwab deal with the former, while in the next section Burrett, Embleton Schmidt & Fisher, Glikson, Crook, Kremp, the Termiers, and Gorai consider ancient configurations.

Interpretation of the Tethys is crucial, because plate-tectonics models imply thousands of kilometres of closure across this zone in contrast to expansion models in which the Tethys was transversely extensional. Crawford, Stocklin, Ahmad, Plumb, Ciric, Tassos, Brimnschweiler, Johnston, and Carey contribute to this debate.

The next section considers the Pacific Ocean, which according to plate-tectonics models, must have shrunk to half its area since the Permian (to make room for the opening of the Arctic, Atlantic, and Indian Oceans), whereas expansion models imply great area increase in that time. Davidson, Shields, Bevis Payne, Iturralde-Vinent, and Tanner discuss aspects of this question.

The intrinsic nature of orogenesis is the most fundamental question of geology. Plate-tectonics theory considers orogenesis to be the result of many hundreds of kilometres of transverse shortening caused by subduction between converging plates. Many expansionists consider diapiric extrusion from the interior to be the primary cause, and that orogens widen during the process. Other expansionists, take an intermediate position invoking compression during the diastrophic phase. Subduction problems and diapirism are discussed by Tanner, Ramberg, Scholl & Vallier, Ciric, Cecione, and Wezel.

In the next section three papers (Dachille, Shields, and Myers) attribute the expansion of the Earth to impacts of meteoritic bodies, asteroids, and comets.

Many of the papers touch on the rate of expansion, but in the next section three (Neiman, Talobre, and Blinov) consider this question specifically and attempt to quantify it, and Stewart sets quantative limits derived from his earth model.

Dooley and Runcorn cite geophysical data contrary to the expansion model. Walzer F, Maaz discuss in depth the physical base of mantle convection, which is relevant both to expansion and conventional tectonic models. No papers were offered on pulsation theories of Earth expansion which however have several supporters (e.g. Steiner, Milanovskii, and Khain).

The final section discusses. planetological (Taylor) and cosmological (Tryon, Carey) implications of Earth expansion, with short papers on relevant matters of entropy (Tassos) and fundamental dimensions (Parkinson).

In a closing review, the convener states the necessity of Earth expansion.