Very few artifacts recovered from an archeological site can be absolutely dated. Archeologists use several methods to establish absolute chronology including radiocarbon dating, obsidian hydration, thermoluminescence, dendrochronology, historical records, mean ceramic dating, and pipe stem dating.

What is biostratigraphy for?

Biostratigraphy is the branch of stratigraphy that uses fossils to establish relative ages of rock and correlate successions of sedimentary rocks within and between depositional basins. A biozone is an interval of geologic strata characterised by certain fossil taxa.