The successive positions of the palaeomagnetic pole. The individual pole position is calculated assuming the observed field is that of an axial geocentric dipole. As the Earth’s axis of rotation is fixed relative to the ecliptic, the changing positions of the pole, as a function of time, are due to the motion of the tectonic plate from which rock samples were obtained. The pole path is therefore, more strictly, an apparent polar wander path. Sudden changes in the pole path (‘hairpins’) are usually caused by continental plate collisions and ‘superintervals’, between hairpins, correspond to the motion of a plate with little or no collisional interactions with other plates.