Posted by: paulgarner | February 17, 2011

Do creationists “admit” that the Navajo Sandstone was deposited in a desert?

Greg Neyman runs the Answers in Creation website, which is dedicated “to supporting Christians who believe in an old earth”. The site hosts book reviews and articles responding to the arguments of young age creationists, and seeks to persuade Christians that acceptance of an old earth has no adverse theological consequences.

Several pages on the site refer to sandstones thought by most mainstream geologists to have been deposited in desert environments and suggest that flood geology cannot explain them. Since this is an area of research in which I have some interest and experience, I thought I’d take a look at what Neyman had to say.

I soon came across this article, in which Neyman asserts that the Navajo Sandstone (U. Tri?-L. Jur.) of the Colorado Plateau is clearly a desert sandstone. However, what really caught my attention was this claim:

Here is the most amazing evidence for the desert, wind-formed Navajo Sandstone. Creation scientists themselves admit it! I don’t know if they are aware of this or not.

I was certainly not aware of it and so I was intrigued to find out what Neyman’s evidence was for this claim. Neyman refers the reader to the creationist book, Grand Canyon: Monument to Catastrophe, published by the Institute for Creation Research in 1994, and says:

On page 32 of this book, they are making a case for the Coconino Sandstone of the Grand Canyon. They claim it was deposited not in a dry, desert environment, but in a water environment. Figure 3.10 shows a plot of grain sizes for the Coconino, two modern water environments, and a “Desert Sand Dune.” Through this plot, it is shown that the desert dune plots out to a straight line, whereas the Coconino, and the water environment sands, plot out as jagged, irregular lines. This is used as proof that the Coconino is not a desert sandstone.

Okay, so far, so good. But then he says:

The amazing thing is the source of the “Desert Sand Dune” grain size plots. The first paragraph in the right column, first sentence, gives the source as footnote number 44. If you turn to this footnote, the source of the desert sand grain size plot is “Stratigraphic Analysis of the Navajo Sandstone,” published in the Journal of Sedimentary Petrology! That’s right! These creation scientists are using the desert-created Navajo Sandstone to argue against the Coconino as being desert in origin.

He concludes triumphantly:

We now have proof, from young-earth creation scientists themselves, that the Navajo Sandstone formed as a dry, desert sandstone, right in the middle of Noah’s Flood!!!! Without meaning to, they have proved the old age of the earth!

Neyman makes the same claim in his review of Grand Canyon: Monument to Catastrophe.

However, it didn’t take long for me to realise the mistake that Neyman had made. Because (unlike him, or so it appears) I’ve actually read that paper in the Journal of Sedimentary Petrology. In fact I have a copy right here on my desk. The authors are William Freeman and Glenn Visher and the full citation can be found below. Yes, Neyman is right: the paper presents a stratigraphic analysis of the Navajo Sandstone. And, yes, it contains log-probability plots of grain size distributions for various sand and sandstone samples. And, yes, those plots include log-probability grain size distributions for the Navajo Sandstone.

But (and here’s where Neyman failed to do his homework) a cursory examination of the paper reveals that the “desert sand dune” grain size plot in Grand Canyon: Monument to Catastrophe is not one of the plots derived from the Navajo Sandstone. In fact, it represents Holocene (i.e. modern) desert sand samples that were being compared by Freeman and Visher with samples from the Navajo Sandstone! The authors provide several similar-looking plots from modern eolian dunes in their Figure 7 on page 656.

In fact, one of the key arguments that Freeman and Visher advance in their paper is that the log-probability plots of Navajo Sandstone samples are much more similar to those taken from modern marine shelf and estuarine sands than they are to modern desert-eolian sands. On page 656 they write:

There is considerable contrast between Navajo curves and Holocene desert-eolian curves. Specifically, in eolian curves, a steep, well-sorted, dominant saltation population develops with the bed-load and suspension populations much less pronounced or entirely absent … ; Navajo grain size curves have less well-sorted saltation populations and although in some cases lacking a coarse poorly-sorted bed-load population, the majority has suspension populations marked by a 3.24-3.75 phi break … There appears to be no systematic location of intrapopulation or interpopulation breaks in eolian curves.

In sum, Freeman and Visher are arguing against an eolian origin for the Navajo Sandstone – the very opposite of what Neyman is trying to do.

So here’s some advice for Greg Neyman. You run a website that seeks to take the high ground against what you see as the “false assumptions, deceits, and half-truths” of young age creationists. By all means be critical. But if you’re going to accuse creationists of misrepresenting or misunderstanding a scientific paper, then at least read it first – otherwise you might find that you’ve committed the very errors that you perceive in others.

References

Austin S. A. (editor). 1994. Grand Canyon: Monument to Catastrophe. Institute for Creation Research, Santee, California.

Freeman W. E., Visher, G. S. 1975. Stratigraphic analysis of the Navajo Sandstone. Journal of Sedimentary Petrology 45(3):651-668. (See also the extensive discussion of this paper and a response from Visher and Freeman in Journal of Sedimentary Petrology 47(1):475-497, 1977).

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