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Date: | Wed, 22 Sep 1999 17:27:09 -0400 |
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Andrew Vik
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John:
Several years ago, I read about a species of desert shrub in the southwest US
that had been dated at around 14,000 years old. This plant starts out as a
normal looking bush. As it grows outward, the original mass in the middle
dies. This process eventually leads to a large ring of scrub with bare earth
in the middle. The researchers dug up the semi fossilized original stumps at
the center of the rings and did carbon dating to arrive at the 14,000 year
mark. While it is true that the original plant had died long before, the
entire ring came from just one seed sprouting a very long time ago.
Andrew
Cramer, John wrote:
> True, the oldest living bristlecone pine is about 4700 years old. The
> 20,000 figure Mark used is about right for the length of the tree ring
> record. That is, current living trees plus dead but still extant trees
> combine to give a much longer record than that available just from living
> trees. This record has been critical in calibrating the carbon 14 dating
> technique.
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