Obsidian Samples from Archaeological Sites in Northwestern Alaska: A Preliminary Report

Résumé

Reports the Na and Mn contents and Na/Mn ratios, determined by neutron activation analyses of 103 obsidian samples from the Onion Portage and nine related archeological sites. The occurrence and stratigraphic distribution are noted of four groups of obsidian distinguished by Mn content and Na/Mn ratio. Group B, the largest, appears in a complex with an age of 4000-3900 BC and in another of 1000-1700 AD, group A in complexes dating at 2600-2200 and 1500-500 BC, group C occurs 2200-1800 BC; and group D 400-1700 AD. There are at least four obsidian sources represented whose geographic locations are unknown.