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.