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Disagreements on the post-Flood boundary: a reason to doubt biblical creation?


The location of the Flood-post-Flood boundary in the rock record is a long-standing disagreement among creation researchers (figure 1). Some advocate for a low boundary at or near the Cretaceous-Paleogene (K-Pg) horizon, which is associated with the ‘extinction of the dinosaurs’. Others place it much higher in the Cenozoic, even as high as the Neogene-Quaternary boundary. How should a layman handle a long-standing disagreement like this among creation researchers? Is this a cause for doubting biblical creation overall? Jonathan S. from Germany writes:

Dear CMI team,

First of all: thank you for your efforts and all the information you provide for free. I really enjoy your articles, and they have tremendously impacted my faith.

Recently, I started to dive into the question of the post-flood boundary. I think there is good geological evidence against the K/T-boundary (I have read every article by Oard, Clarey, and Walker on this topic). However, I am quite puzzled about different evidence regarding fossil-succession (see Ross (2012) or, more recently, Arment (2016,2020a,2020b)). I have read through your published exchanges and find that these problems are mostly ignored or belittled by doubting the fossil database’s overall precision (see Walker vs. Ross or Oard vs. Arment), which I find wanting.

I write to you because this topic turned out to be a real stumble-stone for me as both analyses seem very solid yet contradict each other.

Could you provide some ideas that might help reconcile these positions?



CMI’s Shaun Doyle responds:

Dear Jonathan,

Thank you for your email. I have tossed it around to some of the geological minds here because you’ve raised a very important issue.

Shaun Doylefig-1
Figure 1. Live options for the location of the Flood/post-Flood boundary relative to the geologic column.

The post-Flood boundary issue is an ongoing debate within the creation geology community, and it’s one that is not yet resolved. You raise an incredibly good point about datasets in tension with each other. On the one hand, there are many strong geological reasons to place the post-Flood boundary above the K-Pg horizon. The most important of which include: the sheer volume of Tejas megasequence sediments (they form 20–30% of all Phanerozoic sediments!),1 the fact that many of the thickest and most extensive coal beds are found in the Cenozoic,2 and the fact that much of the oceanic crust is Cenozoic in radiometric ‘age’ (so, did the continents still have hundreds to thousands of km yet to move at the end of the Flood, as a K-Pg post-Flood boundary would seem to imply?).3 I have not seen K-Pg post-Flood boundary advocates deal with this adequately in print.

But does this tell us precisely where the post-Flood boundary is? No. Clarey has suggested it’s at the Neogene-Quaternary boundary,4 but there are difficulties with that option. Arment’s recent work,5,6 as well as Ross’ arguments from a few years ago,7 show that there isn’t a nice line in the Cenozoic to draw between Flood and post-Flood fossils. They argue that this cannot simply be cast aside as ‘uniformitarian interpretation’. The fossil patterns are too systemic for that to work. Plus, Arment especially makes his case not simply from uniformitarian biostratigraphy, but also from baraminology and post-Flood biogeographical assumptions. And, as you’ve pointed out, the responses from Late Cenozoic post-Flood boundary advocates haven’t really addressed this issue well up till now. I agree with you on this (though I speak for myself on this, and don’t necessarily speak for all of CMI). I think Arment has made a powerful case against any idea that we can posit a distinct and globally synchronous ‘post-Flood boundary’ in ‘geologic column’ categories (e.g. saying that ‘the post-Flood boundary is at the Eocene-Miocene boundary’—or the Neogene-Quaternary boundary). Ross also suggested that the highest level we find a major discontinuity in the global fossil record from creatures alive today would be the most likely place for the post-Flood boundary.7 Since the K-Pg seems to fit that criterion, that seems a likely place for the post-Flood boundary.

But does that work? Does the work of Arment and Ross argue for a K-Pg post-Flood boundary? I think that moves too fast. To argue against a higher post-Flood boundary is not to argue for a lower one. Nor does it argue against one that varies with respect to geologic column classifications. Plus, the very same data presents a biostratigraphic problem for a K-Pg boundary: practically all fossils of recognizably extant mammals are confined to the Cenozoic, but if they are all post-Flood, where did all the fossils of mammals we recognize go? Did they all just get eroded away? Nor does it solve the geological difficulties with a K-Pg post-Flood boundary.

There is a third option we could consider: a ‘variable boundary’ view. Oard8 and Walker9 have suggested the boundary may be variable with respect to geologic column assignments (e.g. the post-Flood boundary may be in the ‘Miocene’ in one area and the ‘Pleistocene’ in another). (This can be somewhat confusing, since Oard has been perhaps the main proponent of a ‘Late Cenozoic’ post-Flood boundary. However, he has also made it clear that he doesn’t think there is likely to be a distinct and globally synchronous ‘post-Flood boundary’ in ‘geologic column’ categories.)

But this view has its challenges, too. First, is it an ad hoc saving device for a high post-Flood boundary? This doesn’t make much sense. It simply acknowledges that there are global features of the Cenozoic rock record that are difficult to explain as post-Flood. This is manifestly true. But unlike a uniformly high boundary, a variable boundary proposal allows for the local geology to speak most loudly on the question. But the biggest difficulty with this view is that it calls into question a lot of cross-linked geological work long-agers have done. If the latter is an option, then it would require a lot of work to uncover and fix.

So, where does that leave us? It leaves us with good geological reason to doubt a K-Pg post-Flood boundary, good paleontological reason to doubt a globally synchronous post-Flood boundary that can be correlated with standard geologic column categories within the Cenozoic, and a lot of work to make the variable boundary proposal viable. It seems to me that this means we don’t have a good proposal, right now. Instead, I think we should look at the most fruitful option to explore at present. That I believe is the variable boundary proposal. We cannot simply assume that the geologic column categories that may work well for long distance correlation of things during the Flood will apply equally as well to a boundary. What if the post-Flood boundary isn’t a sharp disjunct, but is a gradual transition? Wouldn’t we expect local geology to provide the clearest clues on the specifics of a boundary case like the post-Flood boundary? As such, general chronological indicators may only ever provide a first approximation for the post-Flood boundary. We need then to be guided by local geology.

I’m not saying that the variable boundary view is correct, or even the most likely to be correct. I’m just saying that the questions revolving around the boundary make it the most open-ended and fruitful proposal for future research. Starting with stricter boundary views seems more likely to create confirmation bias, at present.

Interestingly, both sides of this debate have suggested that the location of the post-Flood boundary may differ from place to place. For instance, Snelling (who generally advocates for a post Flood boundary at or near the K-Pg boundary) has placed the post-Flood boundary in Israel during or at the top of the Oligocene.10 And it’s reflected in the theory behind defining the post-Flood boundary for both parties, as illustrated by Oard11 and Whitmore and Garner.12

So, if both parties are willing to move away from hard-and-fast boundaries that are tied to a single position on the geologic column globally, why is there still such a big debate? It has to do with the nature and extent of post-Flood catastrophism. Exactly how much is too much? Whitmore has made a case for the feasibility of extensive post-Flood catastrophism,13 but it hasn’t really convinced Late Cenozoic proponents.14 And, admittedly, I can understand why. Consider this statement from Whitmore on the global tectonics in a post-Flood world:

“If the Cenozoic is mostly post-Flood, there has been a significant amount of plate tectonic movement in post-Flood times (a good bit of the ocean floor is Cenozoic; Austin, et al., 1994). It also appears that many mountain ranges had significant amounts of uplift late in the Cenozoic (Ollier and Pain, 2000), although many had significant amounts of uplift prior to this too (like the Rockies and the Appalachians). Both continental movement and mountain uplift have great geomorphic implications. Plate position affects ocean currents which in turn affects ocean temperatures, weather patterns and climate. Mountain uplift of course can lead to many avenues of denudation.”13

This presumes his perspective and doesn’t give us any reason to think so much Catastrophic Plate Tectonics (CPT) is geologically plausible in a post-Flood scenario. But this is all he says on CPT and the Cenozoic in this article. This is frustrating, because he does the work to show some level of plausibility on other fronts. But as far as I can see this is the biggest geophysical problem with extensive post-Flood catastrophism, especially since Whitmore accepts CPT.

From this, it’s probably plain that my sympathies rest with a tendency to place the post-Flood boundary higher in the Cenozoic rather than lower. But they are sympathies and tendencies; I’m open to revising them in the light of new and better data and research. There are simply too many tensions between datasets and too many unknowns at present to be sure one way or the other. So, more research needs to be done. And it needs to be done in an interdisciplinary way. This interdisciplinary approach, unfortunately, has not yet been done. The closest one finds to it is our forum on the Green River Formation back in 2006. However, this was in some respects more adversarial than collaborative, and both views have difficulties. Plus, neither author has changed their minds in the 15 years since, and both have other supporters for their views among creation geologists. Indeed, you should notice that this debate often follows disciplinary lines: the more people lean on palaeontology, the lower they’ll place the boundary; and the more they lean on the physical rock relationships and geophysics, the higher they tend to place the boundary.

All this to say: I’m about where you are. I’m undecided, and I’m not sure what the answer will be. I can’t go along with a strict K-Pg post-Flood boundary, but biostratigraphy provides difficulties for a single line high in the Cenozoic, too. And I say this after following this debate for 15 years, and I have edited most of the articles in Journal of Creation on this topic over that time.

But here’s the ‘rubber hits the road’ question: is this a cause for doubting biblical creation? Not at all. All broad frameworks have anomalies and difficult-to-handle datasets. After all, models are simplified representations of reality. Is it any wonder that reality is more complex than our theories often account for?

Consider theoretical physics, right now. Both quantum mechanics and general relativity are well grounded scientific theories, and yet we can’t combine the two into a single explanatory theory. Does this mean one or both of them need to be modified or abandoned? Yes. As they currently stand, they can’t both be true. That’s basic logic. But we don’t know which one is the problem. Or perhaps they’re both problematic. We just don’t know. Similarly, the current apparent conflict between geological and fossil datasets concerning the post-Flood boundary is only ‘as far as we know’, and we don’t really know all that much. We certainly don’t know enough to reliably mark the post-Flood boundary everywhere.

Plus, our warrant for believing in biblical creation doesn’t rest on resolving this debate. Rather, it rests on what the Bible says about creation and the history of nature, and we can trust that because Jesus did. If you trust in Jesus and the Bible he believed in, then you’re on solid ground for believing in biblical creation. Don’t let this debate sway you from that. But keep reading! And watch this space! Research often moves slower than apologetics appreciates, but the lesson there is to rest your apologetics on the firm foundation of the Living Word and his written Word rather than the theories of men (even men who believe in the Word). See Unsolved mysteries for more information on handling these sorts of issues.

Kind regards,
Shaun Doyle
Creation Ministries International

Published: 8 May 2021

References and notes

  1. Clarey, T., Carved in Stone, Institute for Creation Research, Dallas, TX, p. 326, 2020. Return to text.
  2. Clarey, T.L., Floating forest hypothesis fails to explain later and larger coal beds, J. Creation 31(3):12–14, 2017. Return to text.
  3. Clarey, T.L., Local catastrophes or receding floodwater? Global geological data that refute a K-Pg (K-T) Flood/post-Flood boundary, CRSQ 54(2):100–120, 2017; p. 116. Return to text.
  4. Clarey, T.L. and Werner, D.J., Compelling evidence for an Upper Cenozoic Flood/post-Flood boundary: Paleogene and Neogene marine strata that completely surround Turkey, CRSQ 56(2):68–75, 2019. Return to text.
  5. Arment, C., To the Ark, and back again? Using the marsupial fossil record to investigate the post-Flood boundary, ARJ 13:1–22, 2020. Return to text.
  6. Arment, C., Implications of Creation Biology for a Neogene-Quaternary Flood/post-Flood boundary, ARJ 13:241–256, 2020. Return to text.
  7. Ross, M.R., Evaluating potential post-Flood boundaries with biostratigraphy—the Pliocene/Pleistocene boundary, J. Creation 26(2):82–87, 2012. Return to text.
  8. Oard, M.J., The geological column is a general Flood order with many exceptions, J. Creation 24(2):78–82, 2010. Return to text.
  9. Walker, T., Research needed to resolve questions with late Cenozoic post-Flood boundary, J. Creation 28(2):63–66, 2014. Return to text.
  10. Snelling, A.A., The geology of Israel within the biblical Creation-Flood framework of history: 2—the Flood rocks, ARJ 3:267–309, 2010. Return to text.
  11. Oard, M.J., Defining the Flood/post-Flood boundary in sedimentary rocks, J. Creation 21(1):98–110, 2007. Return to text.
  12. Whitmore, J.H. and Garner, P., Using suites of criteria to recognize pre-Flood, Flood, and post-Flood strata in the rock record with application to Wyoming (USA); in: Snelling, A.A. (Ed.), Proceedings of the Sixth International Conference on Creationism, Creation Science Fellowship, Pittsburgh, PA, pp. 425–448, 2008. Return to text.
  13. Whitmore, J., The potential for and implications of widespread post-Flood erosion and mass wasting processes; in: Horstemeyer, M. (Ed.), Proceedings of the International Conference on Creationism, Vol. 7, Creation Science Fellowship, Pittsburgh, Pennsylvania, Article 15, 2013. Return to text.
  14. Oard, M.J., Flood processes into the late Cenozoic— part 7: critique of a post-Flood Cenozoic, Journal of Creation 33(2)99–106, 2019. Return to text.

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