Ron Towner from the Laboratory of Tree-Ring Research at the University of Arizona explains the principles behind dendrochronology and why this dating method is valuable to archaeologists. Ron demonstrates how to accurately count tree-rings, and discusses the importance of patterns and master chronologies. Trees are often used to make analogies about the past. Family trees, the tree of life, getting back to your roots…. But beyond the powerful imagery that trees give us to represent our history, what can trees actually tell us about the past?
Dendrochronology is the formal term for tree-ring dating, the science that uses the growth rings of trees as a detailed record of climatic change in a region, as well as a way to approximate the date of construction for wooden objects of many types. As archaeological dating techniques go, dendrochronology is extremely precise: if the growth rings in a wooden object are preserved and can be tied into an existing chronology, researchers can determine the precise calendar year—and often season—the tree was cut down to make it. Radiocarbon dates which have been calibrated by comparison to dendrochronological records are designated by abbreviations such as cal BP, or calibrated years before the present. Tree-ring dating works because a tree grows larger—not just height but gains girth—in measurable rings each year in its lifetime.
Carbon Dating - Dendrochronology As we've already seen, in order for Carbon dating to work we need to know what the C to C ratio was at the time of a specimen's death. If the ratio has fluctuated throughout the unobservable past and we can be sure that it has , how can we determine what the ratio was during the lifetime of a specimen that lived and died before we first began measuring the ratio? Advocates of the Carbon dating method have turned to "Dendrochronology" a. By carbon dating a piece of wood which has also been dated by counting its annual tree-rings, scientists can create a table by which they can convert the questionable Carbon years into true calendar years.
Jump to navigation. The practical applications of the study of tree rings are numerous. Dendrochronology is an interdisciplinary science, and its theory and techniques can be applied to many applications. See our subdisciplines for examples. These research interests have in common the following objectives:.