You searched for: “dendrochronology
dendrochronology (s) (noun) (no pl)
The science of tree-ring analysis and its implications: The research of dendrochronology employs a method of dating using annual tree-rings, also termed tree-ring chronology.

In archaeology, dendrochronology utilizes a system of dating wooden objects by analyzing the pattern of their annual rings and comparing this pattern to an established tree-ring sequence for the region.