In simple terms, Dendrochronology is the dating of past events (climate changes) through study of tree ring growth. Botanists, foresters and archaeologists began using this technique during the early part of the 20th century. Each year a tree adds a layer of wood to its trunk and branches that create annual rings. New wood grows between the existing wood and bark or the cambium layer. In the spring, when moisture is plentiful, the tree devotes energy to producing new growth cells. These first new cells are large, but as the summer progresses their size decreases until, in the fall, growth stops and cells die. No new growth appears until the next spring. The contrast between these smaller old cells and next year’s larger new cells is enough to establish a ring that makes count possible.
How Dendrochronology Relates to Tipton-Haynes
The log barn and corn crib on our historic site has been dated to the 1850s or the time of Landon Carter Haynes residency here. Using special equipment, archaeologists drilled small holes into the logs of the historic buildings from the bark to the core. When the samples are compared to many other dated samples, they can tell the approximate age of the building. This study supports the idea that Haynes was the person who had the barn and corn crib built. A core was taken from the foundation logs of the Tipton cabin. It dated to 1798 and we believe that Col. Tipton had two log structures, first when he moved to Tennessee and the second in 1798.
Students will learn through discussion the process of how archaeologists determine the age of log structures through dendrochronology. The history behind the Landon Carter Haynes barn and corn crib will be discussed. Students will be allowed to see and feel the holes of the corn crib that were drilled during the 2008 archaeological excavation. Each student will then be given a small piece of wood to count the rings and try to determine the age of the wood and the environment in which the tree lived. Students will then paint and/or color their piece of wood to create a dendrochronology medallion necklace.