"Nick Maclaren" wrote in message
...

In article ,
"Charlie Pridham" writes:
|
| When dating trees they use the combination patterns of narrow and thick
| rings which correspond to the different seasons (wet dry cold warm
years),
| they hold data bases for various tree types and the result is read much
like
| a bar code.
| they reckon to be pretty accurate. but I gather all you want is an
| approximate age so probably not worth paying from the former!

It's not quite that simple, but I think that they can date
suitable timber with precision to the year some millennia
back, and get to about a hundred millennia with some precision.
They do need to know where the timber came from to do that, as
the year pattern vries with location.
~~~~~~~~
By comparison with the data library the location can be identified.
The whole process is, as you suggest, very accurate.
Best Wishes Brian.


Regards,
Nick Maclaren.