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First off: I don't think many of the arguments here would be used before a school board by proponents of intelligent design/creationism. Certainly biblicial geneaology, and references to navy ships = Noah's ark would not be part of the presentation. They would be red flags and most advocates have been coached to avoid them.

The more likely approaches would be, in rough descending order of recent popularity: "academic freedom," free speech, "equal time," "gaps" in the fossil record, "it's only a theory," and other, more conceptual approaches. Attacking science as being equivocal and lacking in absolutes has been the most recent strategy.

But about the picture: There are areas where successive ashfalls bury trees in a thick layer or two of tephra -- the first layer is from the eruption which killed the tree and buried most of the trunk, and then other eruptions, a few months or years afterward, leave successive layers. Trunks don't last long, though, so you rarely get lots of layers. Could be somehting like this, since you could without too much hassle excavate a "large" pit in ash.

Another example would be varves -- seasonal deposits on the bottoms of lakes. If there was fine dark-light-dark-light banding, the site could be a filled-in lake. Occasionally trees sink to the bottoms of lakes and get buried, although again, varves are usually very thin and years of deposits are required to build up a few centimeters, and trunks might not last long enough.

Still, in both cases the lower layers *were* there before the upper ones. So they *still* represent different time periods, just not millions of years apart. His point I'm sure.

But without more information, and assuming the excavated material is unconsolidated, it could be: dry ravel down the sides of the pit, a trick of the light, filled-in postholes, filled-in tree roots, faults, etc. etc.

In any case, this claim (superposition) will no doubt be discarded at convenience, when it's necessary to claim the validity of an archaeological site.

> Dr. Harrub did present some pictures of an area being excavated.  The 
> excavation was sufficiently large to expose many layers of 
> different types 
> of sedimentation.  Within the vertical structure were columns 
> that appeared 
> to be a homogeneous material.  Dr. Harrub claimed that these 
> columns were 
> trees and was proof that different layers of sedimentation 
> did not represent 
> different time periods.  If anyone has knowledge of such 
> columns that I have 
> just described, please post it as I would like to understand 
> this point.
> 
> Jack Cannon


Marc Taylor
Coordinator, Andrus Planetarium
Hudson River Museum
511 Warburton Avenue
Yonkers, NY 10701
914 963 4550 x223
Fax 963 8558
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