A stable Ediacaran Earth recorded by single silicate crystals of the ca. 565 Ma Sept-Iles intrusion

The archetypical example of inertial interchange true polar wander (IITPW), the rapid rotation of the entire solid Earth by 90 degrees, is based on two nearly orthogonal directions seen in paleomagnetic studies of the Sept-Iles (ca. 565 Ma) intrusion (Quebec, Canada). This motion has also been proposed as the driving force for the early Cambrian explosion of life. Others have challenged these interpretations, linking the data instead to flips between an axial and equatorial dipole field configuration. We examine this enigma using single silicate crystal paleomagnetic analyses. We conclude that only one of the previously reported magnetic directions is carried by single domain magnetic grains and can be considered primary. Thus, the Ediacaran diversification occurred on a rotationally stable Earth driven by biotic and longer term abiotic forcing. Whether IITPW ever occurred in the past on Earth remains uncertain.