Collecting and Caring for Tree-Ring Samples in the Southwest

Dendrochronology is the most precise and accurate dating technique available to archaeologists, with resolution to the year and sometimes season. As biological specimens from human-produced contexts, dendroarchaeological samples inherently contain three kinds of information: chronological, behavioral, and environmental. The purpose of this short article is to educate archaeologists on how to avoid degrading any of these three types of information through improper sample selection, collection, preparation, or transportation techniques. Dendroarchaeology is not without limitations. First and foremost, it is dependent on the behaviors of people who built structures, made artifacts, and burned wood for fuel. If past people did not use wood, or used undateable tree species, dendrochronology will simply not be useful. In some cases, people used dateable species, but their selection criteria did not meet one of the four basic criteria necessary for successful dating. The second most important factor in successful tree-ring dating of archaeological materials is the behavior of archaeologists. Finally, preservation plays an important role in successful dating and the nature of the derived dates, but the paucity of long-lived old trees and degradation of "legacy" wood on the ground have hampered the development of millennia-long chronologies in more mesic areas.