Re: Want to petrify wood without waiting a few million years?

From: Steven M Smith <smsmith@usgs.gov>
Date: Fri Jan 28 2005 - 12:39:50 EST
Wayne,
 
Good point about the size of the material (1 cubic cm) vs. a whole tree.  I missed that argument.
You wrote (in part);
>>2. &nbsp;The artificial petrified wood is made of silicon carbide (SiC - rarely
>>found naturally on earth and then usually in small flakes associated with
>>iron meteorites) instead of the various forms of silicon dioxide (SiO2)
>>that commonly petrify wood.
> I was also wondering about the composition. But as you
> pointed out in your post below, it is not how fast something
> fossilizes, it's just that _IF_ it becomes fossilized, there
> is a greater chance that we might be able to discover it.
> In fact, now that I think of it, rapid fossilization would
> be better for radiometric dating. If the fossilization
> process must take millions of years, then it increases the
> margin of error.
Generally, and with a few exceptions, most fossils are not amenable to direct dating with current radiometric techniques.  We date most fossils by determining the age of the rocks that enclose them.  Fortunately, in the example mentioned in the old ASA discussion post, the layer that encloses the fossil wood also has an interbedded lava flow that can be dated by radiometric techniques - thus we can assign a tentative age range for the petrified wood.
 
I do have a piece of petrified wood that was partially mineralized by uranium (in addition to the normal silicon dioxide replacement).  This fossil could certainly be dated by an uranium-lead radiometric technique.  However, the results would probably reflect only the date when uranium-bearing ground waters seeping through the rock reacted with carbon in the fossil to deposit uranium (same process as used in a charcoal based water filter in your house), which may be significantly younger than the actual age of the fossil.
 

>>3. &nbsp;The rate of petrification (fossilization) has nothing to do with the
>>age of the Earth. &nbsp;(See previous &nbsp;ASA list discussion on fossilization
>>rates at <http://www.calvin.edu/archive/asa/200001/0216.html>)

 

> By the way, I don't think I ever asked, was any of that
> 60 Myr old "unpertrified" wood preserved (or preservable)?
> That seems like such an interesting and unexpected find.
> It is a case in point that things that don't fossilize
> don't end up on display.

To the best of my knowledge, none of that 'unpetrified' fossil wood was preserved after exposure.  I didn't try and I know of no one else who may have tried.  I assume that potentially you could preserve it.  The process would probably be the same as that used for preserving archaeological finds of wooden artifacts removed from peat bogs or undersea sites (i.e. prevent it from drying out and isolating it from oxygen and microbes.)

> I think it didn't quite sink in completely before, but I
> now see that the argument about the fossilization rate
> is really just a strawman.

Exactly.  The same is true for several other 'evidences for a young Earth'.  Under special, artificial, or unusual circumstances many geological features (fossils, stalactites, canyons, oil, ... to name a few canards) can be formed at rates faster than what is presumed to be normal.  My biggest problem with this rate argument is that when you look at the bigger picture you realize that everything in the geological record must have been the result of a whole sequence of extremely unusual circumstances (or miracles) in order to preserve the idea of a 'young Earth'.

----

BTW, does anyone on this list have access to the Advanced Materials (Wiley-VCH) journal either in print or online?  I would enjoy reading the original research article rather than the press release version.

Y. Shin, C. Wang, G. J. Exarhos, 2005, Synthesis of SiC Ceramics by the Carbothermal Reduction of Mineralized Wood with Silica, Advanced Materials (Wiley-VCH), Volume 17, Issue 1 (p 73-77)

Steve

[Usual disclaimers apply.]

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 Steven M. Smith, Geologist, U.S. Geological Survey
 Box 25046, M.S. 973, DFC, Denver, CO  80225
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 Email: smsmith@usgs.gov
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 Received on Fri Jan 28 12:41:14 2005

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