Abstract
This paper presents a formal framework for synchronizing strata and datable artefacts in multi-layered sites. We first present a simple set of rules regarding the definition of safe termini post quem, taking into account cases of uncertain dating and/or uncertain stratigraphic attribution of the artifacts. We then propose a definition of chronologically optimal termini post quem, and a procedure to represent these optimal termini graphically by a step function in a two-dimensional graph. We also propose a definition of chronologically critical artifacts, as a minimal set of artifacts that determine all the optimal termini post quem of a stratigraphic sequence. Finally, we define a measure of the robustness of a terminus post quem, expressed in terms of the number of different artifacts supporting this terminus. We illustrate our approach through the case study of Egyptian scarabs from the site of Beth Shean (northern Israel), a well-known Bronze and Iron Age site that hosted an Egyptian garrison during the New Kingdom (ca. 1540–1070 B.C.E.). We also provide a software utility which assists users in applying our methodology.