The difficulties of dating olive wood

Abstract

Olive wood is difficult to date for a variety of reasons, the most important of which is that one cannot tell visually what is an annual growth increment (usually referred to as a ‘ring’) and what is a sub-annual growth flush of which there may be any number in one growing season. (I have been able to count a dozen or more flushes in olive wood where the end of the growing season was somewhat more clearly marked than usual.) If one cannot determine the ring boundaries with certainty, one cannot do tree-ring dating, period. For Egyptologists reading this note, acacia is just as bad, and for the same reason. For 25 years I had a couple of sections of olive wood in my dendrochronology lab. Every term I would challenge students to tell me how many rings there were on them. No two students ever came up with the same answer and neither could I. An inspection of two different radii on the same piece also yielded widely varying results. (A side issue, not relevant here, is that the size of the ring in an olive tree does not necessarily reflect climatic conditions but rather the energies of the farmer or gardener who brings water to it. Thus olive is useless for purely dendrochronological cross-dating purposes.