Thanks for your comment. For more information see my weblog www.zienenweten.blogspot.com
Those trees are around 2000 years old and were covered by sand and gravel in an old riverbed from the Maas in the south of Netherlands close to the village Stevensweert.
They were digged out by a gravelwinning company.
here in west virginia, usa, my supervisor is originally from Amsterdam. He would like to know where these photos were taken and the estimated age of the trees. Thank you, John