A geomagnetic reversal is described below: Please Register or Log in to view the hidden image! Does the chaotic impulse of a metastable metallic hydrogen (MSMH) comet striking the pebbleshell of earlier comet debris cause the mysterious pole reversals of the Earth? The supermagnetism and super-density of this matter would be enough to totally rejuvenate the intensity of the magma plumes which rise towards the surface imo. A cascade of movement from geomagnetic pole to geomagnetic opposite pole by the mega-comets would create an energy whirlstorm within the Earth's interior. Plate movement would eventually accelerate accordingly and mountain building would proceed at an accelerated pace.
The Milky Way Galaxy's Spiral Arms and Ice-Age Epochs and the Cosmic Ray Connection, Shaviv has done some work which relates the 125 million year spiral arm crossing of the solar system with earthbound catastrophies. I believe that metastable metallic hydrogen, MSMH, in the form of mega-dense comets is the primary cause though and not cosmic rays as he concludes. The extra dense spiral arms suggests a higher MSMH comet impact rate with a higher average size. It should be remembered that disruption of the electric and magnetic fields would reduce the Earth's protection against any increase in cosmic rays.