I ran across this thread and felt I needed to add my thoughts to the mix. Walt's ideas are a theory or at least a hypothesis, but one needs to remember that plate techtonics is also just a theory. Plate techtonics was not even taught when my father went to college. The steps of the scientific method are gauges of testing, likelihood, and reproducibility.
Ideas such as the laws of gravity are considered laws because they have been tested many times and the same results are found every time. An idea such as plate techtonics or Walt's ideas are supported by observation of evidence of past events, as truly testing something on a geologic scale is formidable at best. All theories are in flux as time passes. Atomic theory has progressed from the ideas of element, atoms, electrons, and so on into an all new level of sub atomic particles.
I'll close with the idea that just because an idea comes from the past does not mean it is wrong. We have lost much knowledge throughout history. A good example of this is the use of concrete. It was used in ancient rome, but the advanced knowledge of this was lost to man for hundreds of years. That is it for now. Thank you for your patience on a long post.