ABSTRACT

The reality of continental drift has been rendered much more plausible than heretofore by recent palaeomagnetic investigations. Without prejudicing this reality, it seems therefore an opportune time to investigate the possible causes of such continental drift, if indeed it did take place. A review of the classical theories of orogenesis shows that none of them could yield a valid explanation of continental drift. Drift velocities postulated from palaeomagnetic investigations seem to indicate that the drift is to a degree random. Accordingly, a random walk model with autocorrelation would best fit the postulated values. This idea had been proposed earlier by the writer, but revised values, yielding an autocorrelation time of 30 million years, make the theory more plausible. It is possible that the random walk is caused by random convection currents whose half-life would be equally of the order of 30 million years.