My estimated and calculated guess is:
10.38 tonnes or 20,760 pounds.
I'm basing that on an average diameter of 1 metre (39 inches)
and 12 metres (39 feet)in height.
Cross section area (Pi times the radius squared is):
3.14 times (0.5 times 0.5)
3.14 times 0.25 equals 0.785
height of 12 metres times 0.785 equals 9.42 cubic metres
Here comes a nice bit for the metric folks.....
Approximate maximum green weight for fairly heavy hardwod like Oak is 1 tonne per cubic metre
So now we've got 9.42 tonnes or 20,760 pounds.
Which is bound to be wrong of course !
My guess guess is that it could be 8 tonnes (approx. 17,600 pounds) or even less.
C'mon Sawdust, put us out of our misery !
Pete