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I wish to extend my thanks to both Marc and Erich for the explanations of 
possible causes of vertical columns within sedimentation layers.  Geology is 
one area that I have never had the opportunity to study.  So these 
explanations are particularly helpful to me.

Dr Harrub led into this subject matter with a picture of Spirit Lake after 
the Mount St. Helens eruption.  There were a lot of logs (trees stripped of 
their branches) floating in the lake.  He claimed that as these trees became 
waterlogged and eventually sunk, they did so in an upright position and 
remained upright as they settled on the bottom.  Since trunks do not last 
very long, the sedimentation surrounding the trees could not be millions of 
years old.  According to him, that proved his claim that all sedimentation 
layers are the same age.

Jack Cannon

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