[oldie from the hard drive]
http://www.unibg.it/convegni/NEW_SCENARIOS/Abstracts/Barbiero1.htm
Flavio Barbiero, Centro Camuno di Studi Preistorici, Capodiponte, Italy
CHANGES IN THE ROTATION AXIS OF EARTH AFTER ASTEROID OR COMETARY IMPACTS
Evidence exists that the poles have changed position during the recent past in a very rapid way - in a matter of days. This possibility, however, so far has been disregarded by official science on the basis that such a phenomenon is thought to be physically impossible: no mechanism is known and no energy capable of provoking it. The hypothesis that the inclination of the terrestrial axis in relation to the ecliptic and the position of the poles might change has however been taken into consideration since last century. Some of the greatest scientists of the time, including J.C.Maxwell and Sir George Darwin, considered this problem but decided that the stabilising effect of the equatorial bulge was so great that no conceivable force originating within the Earth could lead to a shifting of the axis, except for the collision with another planet.
They did not take into account, however, the phenomena of instability which could occur to an Earth-like gyroscope, consisting of a plastic shell, easily deformed by centrifugal forces, covered by freely-moving liquids - the only body of this kind in the solar system.
Our work shows that the impact of extraterrestrial objects as small as an Apollo class asteroid could “trigger” a process which in a matter of days would cause a “reshaping” of the equatorial bulge around a different axis, inducing therefore a shift of the poles and a change of the tilt. In order to trigger the process, the peak value of the torque developed by the impact has to overtake a “threshold” value, equal to the stabilizing torque developed by the equatorial bulge. A rough calculation shows that the threshold value can be reached during the impact with a body much smaller than a one-km-sized asteroid.
A shift of the poles would cause world-wide destructive phenomena such as: earthquakes and volcanic activity in all areas interested by adjustments of the crust; violent winds and torrential rains, with unprecedented floods all over the world; wide fluctuations of the oceans’ level, with subsequent temporary submersion of large parts of the continents; perturbation of the magnetic field. On top of that, there would be permanent changes of the climate, due on one side to the shift of the poles (and therefore to a change of latitude of many regions, deviation of oceanic and atmospheric currents and so on); on the other side to the change of the tilt, with subsequent modification of the seasonal pattern.
A shift of the poles occurring at the end of Pleistocene, with all its related destructive phenomena, could explain coherently the climatic situation before that date, and the situation observed after that date, as well as ancient traditions about a world-wide catastrophe.
I still think the Firestone et al book does a better job of explaining the disaster at the end of the Pleistocene.
FWIW, Drake's Passage has always looked to me like slippage of the Antarctic and South American plates westward past a "hard" or stationary spot in the ocean crust; or vice versa; or a combination of both. Same with the Caribbean which has a similar appearance. Like northern S.A. might have been "twisted" to the southeast away from N.A. I'm sure absence of a continental shelf at the eastern tip of S.A. might tell us something; I just don't know what it might be. N.A., for whatever reasons, appears to have retained most or all of its southern and eastern continental shelf.
Anywho, I'm all but convinced our planet went through some significant trauma during historical times and the few that lived to tell about it have been written off as nut cases or cranks by the scientific community™. Odd thing, most of the myths/legends/lore tell the same or similar tale.