They will conduct chemical analyses on existing archaeological collections in order to determine if indeed aquatic resources were a key part of the diet. If so, perhaps farming was not necessary to maintain a way of life that included some of the first signs of settled communities. With NSF funding, Jeffrey Dean and colleagues have continued research at the oldest and largest dendrochronological facility in the world, the Laboratory of Tree-Ring Research, established in 1937 by the University of Arizona. The lab has provided a detailed chronology that is central to Southwestern archaeology as well as data that allows archaeologists to relate climate to culture change. Since the rate of tree growth is determined by environmental conditions, the yearly growth of tree rings vary in form and thickness making it possible to develop a tree ring chronology dating back to our prehistoric past.
Tree ring dating is an accurate technique for determining the dates of archaeological sites.
Small wood samples from sites can be dated within one year, which is far more accurate than radiocarbon dating. Importantly, tree ring data also enable a researcher to understand the environmental conditions at the time the site existed. This knowledge helps us to better understand the history of global environmental change. A primary accomplishment of the most recent NSF grants has been the generation of new tree-ring dates for archaeological sites in the U. S. Southwest, Great Basin, Alaska, and northern Mexico. To date, more than 160 major publications have resulted.