Thursday, May 17, 2007
CRSQ recently published a paper (and made it available online) called Polystrate Fossils Require Rapid Deposition. It describes many polystrate fossils found, including polystrate trees in coal. The model that the paper describes for the formation of the fossils is a floating vegetation mat - "trees dropped vertically into the strata from a log mat floating on the water during the Genesis Flood...During the Genesis Flood, vegetation dislodged by rising waters would float. Many trees would float in a vertical position because of their heavy root ball"
Some of the evidence:
- leaf litter from both deciduous and evergreen trees is abundant along some bedding planes and shows little or no decay
- "in these figures that the tree seems to have pushed the strata downward. In Figure 16, the strata were bowed downward a distance of about 0.5 m. This would be unlikely if the trees grew in place. However, if the trees sank from a floating log mat, then soft strata would have been depressed into a bowl shape upon impact."
Another interesting tidbit:
It is interesting that some of the petrified logs are both permineralized and coalified. Some logs were petrified on the interior, but coalified on the exterior. Figure 17 shows one of the numerous trees left by the miners after excavation of the third coal mine. The tree is coalified on the outside, but coalification only locally penetrates into the interior of the tree. In some of the trees with rings, the rings alternated between petrified and coalified (Figure 18). We do not understand the meaning of this pattern.
Pictures from Ian
The second half of Ian's email is also about polystrate fossils. Ian Juby has been examining the Polystrate fossils at Joggins and has been taking lots of photos. Here's the rest of his email:
Here are three photos from Joggins:
The first one is a wide-angle shot of the cliffs so you can see the tilt to
the south, and the planation surface across the top. There is only one thing
that could plane the edges like that, with no differential erosion visible:
The receding flood waters.
The second one is a polystrate that seems to be everyone's favourite, but it's
actually quite small - maybe cutting through six feet total of strata.
The third one is a nicer one, the ruler on the right is 50 cm long, in 5 cm
If you use the photos in your presentations, I would appreciate a simple credit line link to my website (http://ianjuby.org) , but I realize that's not always feasible or terribly convenient. If you can, it's appreciated, if you can't, oh well then, use'em anyway. If you use them in a book I would appreciate credit line link to my website though please.