"These sudden increases were caused by cosmic radiation events, and appear synchronously in dendrochronological records all around the world"
####
That is a pretty interesting method for dating historical sites. I wonder how much it will change the records as future research is done globally.
It's neat, but practically speaking it's an incremental improvement over what already exists. Dendrochronology is already capable of dating the felling year (which may be years or decades removed from the actual construction date). This allows you to date certain fellings to a particular season under ideal circumstances, and to start local dendrochronological records from a different fixed point.