Applauding Mediocrity: Tl Dating and the Navajo Tree Ring Dates Revisited

Abstract

In their 2002 study comparing Early Navajo period tree ring dates and thermoluminescence (TL) results from sherds and fire-altered rocks, Dykeman et al. (2002:145) applaud the “remarkable correspondence between tree-ring and thermoluminescence results.” However, re-examination of their data suggests that the rate of certain correspondence (40%) is low, and mathematical modeling shows that a similar rate (35%) could be achieved with random guesses for dates. As the Dykeman et al. (2002) article was presented to champion the use of TL dating on sherds and fire-altered rocks, this re-examination yields a call for more extensive controlled testing of the TL method before its widespread use in North American archaeology.