‘Flood geology’ is a branch of Creationism reserved almost exclusively for the hardest of the hardcore Young Earth Creationists, and asserts that the Biblical account of a worldwide flood is not only true, but supported by geological evidence. It’s not actually something new, and as at one time accepted as valid before being replaced with the uniformitarian model, which exists in a much revised form today (local catastrophic events are now recognised as playing a part in the shaping of the Earth’s crust, whereas earlier uniformitarian models rejected them entirely). As with the geological column, flood geology was rejected by scientists before Darwin published On the Origin of Species, and certainy before evolution became as widely accepted as it is today.
Flood geology works on the principle of ‘catastrophism’, or ‘neo-catastrophism’ if you’re pandering to the Creationist terminology; its modern form at the very least accepts that tectonic activity has contributed to the formation of Earth’s geological features, but suggests that such activity occurs several orders of magnitude faster than is seen today or is thought to be possible.
Probably the two most famous names in modern flood geology are Henry M. Morris and John C. Whitcomb, whose book The Genesis Flood has influenced catastrophists since its publication. Both men are unashamedly wed to the Bible, and their ‘theory’ reflects that; the flood they describe is the Noachian flood, and the story of Noah’s Ark is claimed to be entirely factual. While not every YEC adheres exactly to Morris and Whitcomb’s ideas, there is certainly a common thread that they undeniably began.
Ironically, the fossil record and geological column are cited as primary evidence for a global flood, despite the fact that the vast majority of scientists today agree that both strongly indicate an Earth that is much, much older than 6,000 years.
The ‘explanation’ for the fossil record is particularly interesting for how nonsensical it is. Supposedly, the Flood killed almost all life on Earth except for that harboured on Noah’s Ark (a concept I don’t intend to touch with a ten foot pole), which presents a problem, in that the fossil record does not seem to indicate the simultaneous death of millions or billions of animals in a short space of time. According to this catastrophistic model, the various strata were laid down rapidly, with their fossils representing whichever dead animals happened to be within them at the time. YECs will often claim that rapid burial is actually necessary for fossilisation, and that the Flood thus provides the only plausible (try not to laugh) explanation for the fossil record, but this is wrong; while rapid burial is one method by which an organism can become fossilised, it is certainly not the only one, and indeed fossils have been discovered which bear signs of having been left exposed for a time until being buried (or until falling into a peat bog or anoxic lake, or until being covered with volcanic ash…)
The apparent sorting of fossils in rock strata is variously explained by the organisms in question having differing abilities to temporarily escape the flood, the differing buyancy of dead bodies, and whether the organism in question would have lived at high altitudes. A curiously small amount of attention is paid to plant fossils, but presumably there’s an explanation for those, too (I haven’t been able to find one).
The existence of so-called ‘fossil graveyards’ is another example of evidence cited for a global flood, with the suggestion that a large number of animals were buried rapidly where they stood. This becomes less likely when you consider that, in life, you never find that many animals in one place – indeed, even herd animals would have trouble surviving if there was that much competition from others. An alternate explanation is that hydrological activity tended to ‘funnel’ large numbers of bodies into one place, where they were subsequently buried.
These fossil graveyards are explainable by local-scale catastrophies (the drowning of large numbers of migrating wildebeests and their subsequent burial by river-bank collapse) or relatively large numbers of fossilisations over a long period of time (the death of animals in tar pits over many years, in conditions which favour fossilisation).
Creationists frequently dismiss radiometric dating out of hand, with weak justification. (Note that there is a difference between radiometric dating and radiocarbon dating – the latter is one type of the former, and radiocarbon dating is largely irrelevant to geological timescales). However, they cannot escape the fact that every dating method available to us – radiometric, ice core, dendrochronology – confirms the idea of an old Earth and rejects that of a young one. It was for these reasons (and with much less accurate dating methods) that earlier geologists first rejected the idea of a global flood.
An equally serious problem is the existence of written historical records (mainly Egyptian and Mesopotamian) that mention neither a global flood or their people’s complete extinction. (And this is one area where C14 dating is used extensively, but well within its known upper limit of usefulness.)
Of course, the idea of a global flood (one that apparently covered all land on Earth, although YECs sometimes disagree on this point) immediately raises the question of where all that water came from and where it went when the flood was over. Again, there are various proposed mechanisms, some more silly than others. Some say that rapid tectonic activity released huge amounts of water from the ocean or underground, while others cite some sort of ‘vapour canopy’ that held massive amounts of water in the Earth’s atmosphere – far more than the evidence suggests was ever possible. My favourite is the suggestion that an enormous ‘shell’ of ice once encapsulated the Earth; as others have frequently pointed out, this would, upon collapsing, act much like an incredibly large meteorite impact.
Each of these proposed mechanisms, and many more besides, have been rejected by the vast majority of experts as pseudoscience. They tend to lay out an explanation for single geological events (rock strata, mountains, valleys etc.) without providing an overarching model capable of explaining all of Earth’s geological features in a way that doesn’t violate the laws of physics.
Creationists like to play an odd game with inference, rejecting it outright when the conclusions drawn are ones that they disagree with, but supporting it enthusiastically when they have supposed evidence of their own crackpot ideas. Flood geology is another area where Creationism rapidly evolves; neo-catastrophism is supposedly far more plausible than the silly ideas of the past, yet in reality they’re both equally stupid. When a Creationist branch fails for long enough, its proponents rework it slightly to give it a veneer of scientific credibility. When this inevitably doesn’t impress, they reduce the absurdities – in practice, they draw further from the strict Biblical account – and the whole dance begins anew.
This is obviously far from a complete rebuttal to flood geology, but I would suggest that your time would be better spent learning about real geology, which is fare more interesting. I’ve included links to some further information, including an excellent YouTube video (its creator goes by the name potholer54 and I recommend the rest of his stuff) and the ever-popular TalkOrigins. Further posts will examine Creationist claims about the fossil record and the Cambrian explosion.
As always, criticism and corrections are encouraged.
Tas Walker’s Biblical Geology (I haven’t looked at this one much, but it seems pretty well put together at least.)