One model of how global catastrophic events might be the origin of our current geologic profile, and cause a cataclysmic global flood (i.e. events must still obey the laws of physics within the model formed by our creation entity), is the catastrophic plate tectonic model. This model follows much of the evidence used to support uniformitarian (gradual) plate tectonic theory but also solves inconsistencies or failures of the uniformitarian model. The creation model recognizes that cold rock denser than the mantle materials below surrounded the original super-continent and began to sink at the start of the flood year. Runaway subduction would sink the ocean floor in that area, displacing mantle material and start large-scale movement throughout the mantle. In areas where the mantle was pulling apart, rifts would form in the ocean floor. As ocean plates separated rapidly, hot mantle material would rise, vaporizing copious amounts of water (super-heated jet streams of steam along rift lines). Steam condenses in the atmosphere and falls as rain, a lot of rain ("and the flood gates of heaven were opened" Genesis 7:11). The catastrophic model has been supported by computer modeling that impressed even uniformitarian geologists (Beard, J,. "How a super-continent went to pieces", New Scientist 137:19, 16 January 1993) and provides reasoning to support magnetic field reversals and large cave formation, and explains high-pressure minerals and uplift of today's mountain ranges. The model is more complex than i am explaining, you can review the scientific literature for more information such as:
"Catastrophic Plate Tectonics: A Global Flood Model of Earth History", 1994, Proceedings of the Third International Conference on Creation, authored by PhD scientists Steven Austin, John Baumgardner, D. Russel Humphreys, Andrew Snelling, Larry Vardiman, and Kurt Wise.
"Catastrophic Plate Tectonics: The Geophysical Context..."
Runaway-Subduction-the-Driving-Mechanism-for-the-Genesis-Flood
As noted by Jonathan Sarfati of Creation Ministries International (CMI):
"under Uniformitarian plate tectonic theory, plates are moving too slowly to penetrate past the upper layers of the mantle; rather, they should blend in long before they reach the lower mantle. Yet studies show that the subducted plates have penetrated much further, and are still relatively cool. This is consistent with the subduction being fast enough to penetrate the mantle, and recently enough so they have not had time to heat up."
Some suggest that the catastrophic volcanism of mantle origin associated with extinction events was triggered by asteroid impacts. Tectonic plate motion over the hotspots was periodically disturbed, as shown by clearly marked bends in the sea mount ranges, the Hawaii-Emperor chain being probably the best example. The idea of impact-triggered volcanism became more and more common in the literature in the early 1990s. It is reasonable to attribute these disturbances to impacts during the overall catastrophe on a global scale. Extraterrestrial impacts might explain a sudden conversion of metastable material in the upper mantle to a denser phase—a prerequisite for the catastrophic plate tectonics model.
As a side note, an interesting theory related to impact dynamics is "shock dynamics":
http://www.newgeology.us/
but this theory has not received sufficient vetting.
The geologic record associated with asteroid craters is a topic of its own and quite fascinating. Some references that relate crater evidence with catastrophic geology:
A Biblically Based Cratering Theory
Impacts and Flood - How Many? and Other Issues
Catastrophic Impact Bombardment Surrounding the Genesis Flood
An Impact Flood Submodel - Dealing with Issues
The geologic record associated with asteroid craters is a topic of its own and quite fascinating. Some references that relate crater evidence with catastrophic geology:
A Biblically Based Cratering Theory
Impacts and Flood - How Many? and Other Issues
Catastrophic Impact Bombardment Surrounding the Genesis Flood
An Impact Flood Submodel - Dealing with Issues
Geologist Tas Walker has developed a geology model consistent with catastrophic events including a massive flood, and this model is graphically illustrated below. The hydrological considerations explain many geological features that are difficult to explain under uniformitarian models (Oard, M., Defining the Flood/post-Flood boundary in sedimentary rocks, Journal of Creation 21(1):98–110, 2007).
Of continuing debate today among creationist scientists and geologists who are encouraged by the remodeled geology type theory is where the flood to post-flood boundary is located within the framework of the uniformitarian geology theory. Although there are many non-conformities, gaps, and inverted formations (old ones on top of supposed younger ones), and therefore some creationist geologists (reconstruction model type theory) suggest dumping the geologic column entirely and redeveloping a new one.
