On a Possible Giant Impact Origin for the Colorado Plateau.

It is proposed and substantiated that an extraterrestrial object of the approximate size and mass of Planet Mars, impacting the Earth in an oblique angle along an approximately NE-SW route (with respect to the current orientation of the North America continent) around 750 million years ago (750 Ma), is likely to be the direct cause of a chain of events which led to the rifting of the Rodinia supercontinent and the severing of the foundation of the Colorado Plateau from its surrounding craton.

It is further argued that the impactor most likely originated as a rouge exoplanet produced during one of the past crossings of our Solar System through the Galactic spiral arms in its orbital motion around the center of the Milky Way Galaxy. Recent work has shown that the sites of galactic spiral arms are locations of density-wave collisionless shocks. The perturbations from such shock are known lead to the formation of massive stars, which evolve quickly and die as supernovae. The blastwaves from supernova explosions, in addition to the collisionless shocks at the spiral arms, can perturb the orbits of the streaming disk matter, occasionally producing rogue exoplanets that can reach the inner confines of our Solar System. The similarity between the period of spiral-arm crossings of our Solar System to the period of major extinction events in the Phanerozoic Eon of the Earth's history, as well as to the period of the supercontinent cycle (the so-called Wilson Cycle), indicates that the global environment of the Milky Way Galaxy may have played a major role in initiating Earth's past tectonic activities.