| Obsidian is a volcanic glass that was used by people in the past to make stone tools.Most of the obsidian from the Snake River Plain in southern Idaho is geochemically distinct which means that it can be sourced. Obsidian sourcing analysis is one method for studying mobility patterns of people in the past. 392 lithic artifacts from the Dean Site(10TF01) in southern Idaho were analyzed by portable x-ray florescence spectrometry and compared to samples taken from the known sources on the Snake River Plain. LA-ICP-MS analysis of known source samples is also used for studying how different the Snake River Plain obsidians are from each other. Obsidian performance and predictability is important as it will influence the choice of raw materials used. Performance and predictability can be studied by examining the roughness of obsidian. Obsidians that are smooth tend to be higher quality than those that are rough.Key Words: Obsidian, Snake River Plain, Performance, Predictability, pXRF, LA-ICPMS |