Obsidian hydration dating limitations
More specifically, he asserts that our application of hydration dating to the Copan Valley is flawed by our lack of recognition and control of a wide range of variables.
Braswell's discussion of hydration dating in general, as well as his characterization of the methods and results of the Copan Obsidian Hydration Dating Project, is replete with errors of fact and omission.
Complacent trees have rings of uniform width and therefore have no use for dating.
In sensitive trees environmental conditions influence the width of the annual rings.
Even when the absolute dates are available, we have to supplement the information with relative dating.
In his recent critique of the Copan Obsidian Hydration Dating Project, Geoffrey Braswell (1992) concludes that, in general, hydration dating is too immature a technique to employ successfully.These techniques both place assemblages of artefacts into relative order.Petrie used sequence dating to work back from the earliest historical phases of Egypt into pre-dynastic Neolithic times, using groups of contemporary artefacts deposited together at a single time in graves.This dating method is also known as Archaeological Dating or Historical Chronology. These methods were relied on especially prior to the introduction of scientific methods of dating.But, even when the scientific methods of absolute dating are available, this method of dating has not lost its importance, as many a time we have to depend solely on relative dating.