“Narrowest-Ring” Events in the Irish Oak Chronology: Uncertainties in Reconstructing Cause and Effect in Prehistory

Abstract

A number of “Narrowest-Ring” events have been identified in Irish oaks, with close to calendrial precision, back to 4500 y ago. The nature of these events will be impossible to establish unless putative causes can be precisely dated, independently of the tree-ring chronology. But even if such precise dating were available, alternative causes can be envisaged. Thus, while we can test, in principle, whether an hypothesis regarding the nature of a “Narrowest-Ring” event is acceptable (through adequate dating), we can never establish that it is in fact correct. In addition, it will always be difficult to tie human activities to dated tree-ring events, because archeological dating tends to be imprecise even when using dendrochronology (which yields a date for when a tree was alive, or felled, but not for the date of its use in building). What dates are available for Irish prehistory suggest that major changes in population and culture are associated with the major calamitous events recorded in the tree-rings of Irish oaks.