Now that I have posted revisions to my antipodal theory that change the mechanism for creating volcanism at the antipode of a large impact, I will deal with the questions raised by Eman and Lin about other aspects of the theory that appear to be unworkable.
This email will deal with Eman's notes about geological surface features which move at speeds that are far faster than speeds observed today or imputed in the past.
There are two specific examples of these impossibly rapid movements in my book.
The first example concerns the continent of Western Antarctica, which I describe as "pinwheeling" around the South Pole to its present position.
Eman is right. There is no sensible force that would cause such a radically fast movement. Furthermore, the pinwheeling isn't even necessary. The Western Antarctica continent would be in position to be run into by Eastern Antarctica without any pinwheeling needed. My error.
The situation with regard to the Chicxulub impact and the movement of some of the land on the southwestern flank of Eastern North America is an entirely different situation. In this case, I hypothesize that the Chicxulub impact occurred at latitude 30 degrees north. The Chicxulub crater is currently located at latitude 21 degrees north.
I believe that the Chicxulub impact object came in an angle from the northeast and pushed the land at the flank of the Eastern North American continent to the southwest. The impact may not have moved the crater all the way to 21 degrees north, but I believe that it provided a strong start to that process, along with creating a separation that became the Gulf of Mexico and continued up what is now the Mississippi River, on through New Madrid and several hundred miles beyond.
So, why is this scenario any different than the pinwheeling of Western Antarctica? Because there was a huge force involved and this force was not required to do all that much. It didn't have to move an entire tectonic plate. Rather, it merely had to tear one small side of that plate.
The Mississippi River has covered this continental split with untold billions of tons of silt over the past 65 million years, but the underlying fault is still there and it is still reactive. The Chesapeake Bay impact 35 MYA provided a push to the southwest for the entire Eastern North American continent (at geologically acceptable speeds), which gradually closed the gap and causes the transform fault movement that we see in the New Madrid area today.
The only rapid surface movement that I am hypothesizing involves angled directional force 65 MYA applied to the flank area of Eastern North America, starting at the Chicxulub impact point. This movement would have occurred rather quickly, with much spalling, delamination and liquification of underlying rock.
So, is this possible? I believe that the initial impact force was so huge that it could do this. Furthermore, there is geological evidence that supports this.
There is a geological similarity between the Large Igneous Province (LIP) area in Georgia and Alabama when compared to the LIP area at the tip of the Yucatan Peninsula.
There are also similarities between areas of Belize and Cuba, which would make sense if this Yucatan movement sheared off part of western Cuba as the Yucatan moved to the southwest.
There is also general geological evidence that movement of rock under pressure will cause the moving surfaces to liquify, thus allowing further movement to be far easier.
Finally, there is modeling evidence that an impact of the size of Chicxulub would cause significant liquification of underlying rock. If we add directional force to this equation, why wouldn't movement to the southwest be possible, especially during the time that the vibrational effects of the impact greatly reduced the holding power of friction?
Thanks for your interest. Again, I am always interested in comments.
I'll tackle Lin's question regarding the supervolcano at Lake Toba next.