Single-Grain Optically Stimulated Luminescence Dating Of Prehistoric Ceramics From The Greater Yellowstone Area, Wyoming, Usa
Class
Article
Department
Sociology, Social Work, and Anthropology
Faculty Mentor
Judson Finley
Presentation Type
Oral Presentation
Abstract
Radiocarbon dates from Late Period (<1500 years ago) high-altitude sites in northwestern Wyoming have proven problematic due to a pronounced old wood problem, radiocarbon calibration issues, and limited reliable dating contexts resulting from wildfires. As a consequence, site and regional chronologies prove difficult to build. However, the presence of Intermountain Ware ceramic vessels at such sites provides an opportunity to directly date occupations with optically stimulated luminescence (OSL). The quartz-rich temper of sherds recovered from four sites in the Greater Yellowstone Ecosystem lends itself to single-grain OSL analysis. Resulting luminescence ages provide an age for when vessels were fired and, given assumed brief use-life, when sites were likely occupied. As three of the four sites in this study were discovered after recent wildfires, single-grain dating provides potential mitigation for grains reset as a result of fire exposure. Single-grain methods allow thermally reset grains to be identified and removed from contributing to the final age estimate. Additionally, sherds recovered with charred organic food residue allows for direct comparisons between radiocarbon and single-grain ages. Preliminary results indicate excellent potential for developing a regional chronology for high-altitude occupation through the application and refinement of OSL dating to prehistoric Intermountain Ware sherds.
Start Date
4-9-2015 10:00 AM
Single-Grain Optically Stimulated Luminescence Dating Of Prehistoric Ceramics From The Greater Yellowstone Area, Wyoming, Usa
Radiocarbon dates from Late Period (<1500 years>ago) high-altitude sites in northwestern Wyoming have proven problematic due to a pronounced old wood problem, radiocarbon calibration issues, and limited reliable dating contexts resulting from wildfires. As a consequence, site and regional chronologies prove difficult to build. However, the presence of Intermountain Ware ceramic vessels at such sites provides an opportunity to directly date occupations with optically stimulated luminescence (OSL). The quartz-rich temper of sherds recovered from four sites in the Greater Yellowstone Ecosystem lends itself to single-grain OSL analysis. Resulting luminescence ages provide an age for when vessels were fired and, given assumed brief use-life, when sites were likely occupied. As three of the four sites in this study were discovered after recent wildfires, single-grain dating provides potential mitigation for grains reset as a result of fire exposure. Single-grain methods allow thermally reset grains to be identified and removed from contributing to the final age estimate. Additionally, sherds recovered with charred organic food residue allows for direct comparisons between radiocarbon and single-grain ages. Preliminary results indicate excellent potential for developing a regional chronology for high-altitude occupation through the application and refinement of OSL dating to prehistoric Intermountain Ware sherds.