TECTONICS + MAGNETIC SHIELD. “The approximate coincidence of the Ediacarian biological leap forward with the onset of plate tectonics makes a connection between them possible. The link may be that Earth’s asthenosphere and its internally generated strong dipolar magnetic field both originated then as a result of Sun/Earth/Moon orbital mechanics.”
https://www.sciencedirect.com/science/article/pii/S0012825219302636?via=ihub