Fire Effects on Archaeological Dating Techniques

Fire has the potential to interfere with several common techniques for determining the dates when artifacts were produced that is an important component in attempts to reconstruct the history and meaning of cultural resources from the prehistoric and historic eras. Ash or soot can change the results of carbon-14 dating, inaccurately producing dates that make an artifact appear younger than it is. Very low-intensity prescribed burns in light fuels have minimal impacts on obsidian hydration rims (Linderman 1990). Fires above 170°C-200°C alter the results of obsidian hydration dating (Skinner 2002), a technique that calculates the time when hydration bands were formed to measure the origin of a manufactured artifact. Fires above 675°C (997°F) reorient the electrons that are measured in archaeomagnetic dating techniques to determine the age of stone artifacts. Fires that damage or destroy wood artifacts, and live or dead trees prevent scientists from using dendrochronology to determine dates of origin, tree felling, or of construction. Fire can alter the ability of thermoluminescence to diagnose the age of pottery sherds (Rowlett and Johannessen 1979).