Date of Degree Completion
Master of Science (MS)
Second Committee Member
Third Committee Member
Radiocarbon dating of archaeological sites in the Puget Lowlands can be problematic. Dating specific cultural events associated with features and sites is difficult due to the ubiquity of charcoal in forest soils and poor preservation of bone in acidic soils. These conditions have impeded the development of regional cultural chronologies. The lack of dates for critical time periods also inhibits testing processual models of cultural change. Evidence for the timing and rate of ecological, economic, and political change is critical for testing evolutionary models in the Pacific Northwest (PNW).
Radiocarbon dating highly burned bone (calcined bone) and luminescence dating fire-modified rock from cooking features will improve age estimates for features and sites. Calcined bone survives well in archaeological sites with acidic soils that are common in the PNW. Luminescence dating can be applied to fire-modified rock recovered particularly from food processing features.
This study, conducted in collaboration with the DirectAMS and the University of Washington Luminescence Laboratory, summarizes tests designed to compare dates for paired samples of charcoal, calcined bone, and fire-modified rock. The comparisons are based on a model that includes both the nature of target events and properties of the dated material. Test results show the accuracy and precision of radiocarbon dates for calcined bone and substantiate the utility of luminescence dates.
As possible, two or more of the dating methods should be used together to assign age estimates for features and sites. Within the next 20 years, we may have accumulated sufficient chronometric dates to better outline cultural chronologies for the Puget Sound. More complete chronometric databases and cultural outlines will then better support tests of processual models of cultural changes in the Pacific Northwest.
Brown, James W., "Alternatives to Charcoal for Improving Chronometric Dating of Puget Sound Archaeological Sites" (2016). All Master's Theses. 424.