Re: [Fwd:More radiometric dating problems!]

Steven Schimmrich (schimmrich@earthlink.net)
Wed, 10 Dec 1997 23:14:23 -0500

At 09:52 AM 12/10/97 -0800, Adrian Teo forwarded a letter that claimed:

>Andrew Snelling (a PhD geologist) recently published the results of a
>study (Creation Ex Nihlo vol. 20 no. 1) on the application of
>radiometric dating to the Crinum coal mine in central Queensland,
>Australia.

Snelling does indeed have a legitimate PhD in geology (you have to
check young-earth creationists on this count since some misrepresent
themselves). He also has an interesting method for accommodating his
two worldviews -- I refer you to an essay at:

http://www.skeptics.com.au/journal/realsnelling.htm

>When drilling, miners found pieces of wood 21 meters down entombed in a
>basalt (hardened lava) flow. The wood was in 3 states: ash, charred and
>in-tact. The came from trees that were still growing since an imprint of
>a leaf was also discovered in the basalt.

I've personally never heard of wood embedded in basalt. The melting
temperature of basalt is approximately 1200 degrees C. That's hot enough
to vaporize wood (that's why you never find fossils in igneous rocks). A
leaf imprint REALLY stretches credibility. That should be in a museum!

Basalt commonly fractures upon cooling and it's certainly conceivably that
wood later fell into a fracture in the basalt or you were looking at tree
roots growing into such fractures (as they will do since the fractures are
where the water is. I've seen tree roots in cracks in granite -- does that
mean a tree grew 10 km below the surface of the Earth when the granitic
magma was intruded?

If the wood was recovered from a drill hole, it's difficult to establish
that it was indeed "entombed" within the basalt at the time of formation.
Why could it not have penetrated the basalt at a later date?

>The local geological context makes the basalt flow approx 30 million years
>old, if you accept the standard model. Since the trees were entombed in the
>lava, they also must be approx. 30 million years old. Also what apparently
>looked like tree roots were found in the siltstone below the basalt, which
>suggests the trees were rooted in the siltstone and thus growing on a land
>surface that was then covered by basalt lava. The siltstone belongs to
>the Permiam German Creek coal measures, conventionally believed to be
>255 million years old.

Perhaps the tree roots penetrating the basalt also penetrated into the
underlying siltstone. How thick was this basalt flow? Is there an erosional
surface on top of the basalt? Are there fractures in the basalt?

>Samples of the wood were collected and sent to Geochron Labs in the USA
>and the ANS Lab at the Australian Nuclear Science and Technology
>Organisation (ANSTO) near Sydney. Neither lab was told exactly where the
>samples came from to ensure there would be no resultant bias and both
>labs use the Accelerator Mass Spectrometry (AMS) technique for
>radiocarbon analyses which is supposedly more sensitive. Geochron is a
>commercial company and ANSTO is a major research lab.
>
>Basalt samples from the outcrop of the drill core were sent to the AMDEL
>lab in Adelaide Australia and Geochron for K-Ar dating and basalt
>samples from the drill core were also sent to Geochron.
>
>The labs' staff (all PhD scientists) had no problem calculating
>radiocarbon ages and when questioned were readily insistent that the
>results were within the detection limits with one exception (although
>the other lab did get a valid age from this sample), and therefore
>provided quotable finite ages. They also pointed to the almost identical
>delta C13 results which are consistent with carbon being organic carbon
>from wood and indicating no possibility of contamination. The results
>obtained indicated an age of around 44,000-45,000 years for the wood
>encased in the basalt retrieved from the drill core.
>
>However, the results from the K-Ar dating, which are also staunchly
>defended by the lab staff (again PhD scientists), indicate an age of
>around 45 million years.

I'll take your word on this, not having seen the article, yet I would
like to know essential information like error bars, delta C-13 values, etc.

>So we have a couple of problems:
>1. Dates of the basalt and the wood should be the same but they are
>orders of magnitude apart.
>2. If the basalt is 45 million years old as the geological context
>and the radiometric dates suggest then so must the wood be 45 million
>years old. However, it would not be possible to get a valid radiocarbon
>age from wood that is this old.

We do have a couple of problems, but they're Snelling's problems of
demonstrating what you're claiming here...

As I said before, I'm very skeptical that the basalt and the wood are
required to be of the same age (reasons listed above)

>So here we have another clear cut example of the unreliability of
>radiometric dating methods. It also refutes the claims of some on this
>list who insist that the various dating methods all agree and that the
>error margins are comparatively small and that my previous examples were
>from years ago and that radiometric dating practices and methods have
>advanced so much since then.

It's not clear cut at all. I, for one, am skeptical of an almost
apocryphal story like this. Snelling has a Ph.D. in geology and has
published other, more traditional work, in peer-reviewed scientific
journals (I refer you to the URL I gave previously). Why didn't he
send this off for publication in "Science" or "Nature" since this is
a revolutionary discovery if true.

Don't give me the standard nonsense about bias and how it would be
rejected. You can only claim that if you've tried and I'm willing to
bet it was never even sent to any peer-reviewed journal for publication.

>It appears nothing has changed at all - radiometric dating is still
>completely unreliable for determining absolute ages. So why believe
>them?

The way I see it, this is just another example of a short-on-facts
inconclusive story being used by young-earth creationists in their
attempt to discredit modern science. The only people a story like
this will convince are true believers -- you're dreaming if you think
any reputable scientist (even a Christian scientist) will pay the least
bit of attention to stuff like this until it's properly documented.

At worst, it only shows that radiocarbon dating may give dates TOO
YOUNG for old wood (the K-Ar data was consistent with the regional
geologic context after all). This hardly helps the 6,000 year-old
Earth crowd.

I will try to track down the article anyway. Hey, I have an open
mind and I'm always willing to look at young-earth creationist material
but have always been terribly disappointed by the lack of rigor I always
seem to find when I do so.

- Steve.

--
      Steven H. Schimmrich             KB9LCG  schimmrich@earthlink.net
      Department of Physical Sciences               Kutztown University
      217 Grim Science Building, Kutztown, PA 19530      (610) 683-4437
      http://www.uiuc.edu/ph/www/s-schim     Fides quaerens intellectum