A model suggesting the Earth has expanded significantly over geological time, explaining the relative movements of the continents by the dismemberment of a once complete shell of continental crust.

Modern measurements have shown that the Earth has not expanded at the required rate, and this theory has been all but discarded.

Also known as the 'other' theory of geology and plate tectonics: it has started to acquire a reputation similar to that of creationist geologist, and is not a widely held belief.

See also contracting Earth.