PALEOMAGNETIC-POLE ERRORS AND A SMALL-CIRCLE ASSESSMENT OF THE GONDWANAN POLAR-WANDER PATH

The Gordon, Cox & O'Hare (1984) method has been used for deriving 'sma ll-circle' arcs for a series of independently determined apparent pola r-wander paths. The 'small-circle' approach is considered physically s ensible, but unfortunately still requires excessive subjective 'assist ance' to select the most plausible Euler poles and Euler colatitudes, particularly when there is little relative motion between the continen t and the pole. None the less, polar-wander paths can be divided into prolonged 'tracks' separated by brief 'cusps'. The cusps can be associ ated with particular tectonic events within the continent or groups of continents. This technique thus has the potential for providing a mor e geophysically realistic definition of apparent polar-wander paths th at can be used to help identify non-Gaussian errors in palaeomagnetic data. In addition, the sharpness of most cusps provides a precise age for the onset or cessation of particular tectonic events. The simultan eous occurrence of such cusps in more than one continent also enables an assessment of the global importance of such events.