Abstract

A major lithic mining site in the Cache Creek area, British Columbia, yielded rocks with a dull black appearance and distinctive working characteristics. This material has been referred to as glassy basalt in the literature but petrographic and geochemical analysis (46 major and trace elements) show it is dacite with a high glass content. Attempts to correlate this material with artefacts from a site in the southern Okanagan revealed a second dacite with a different geochemical fingerprint. At least one other dacite quarry site may exist. These preliminary results indicate that dacite was a common stone tool material in the BC interior perhaps acting as a substitute for rhyolitic obsidian which is less common in the area.