Kapahnke, Sheri Louise (2020-08). Applying Optically Stimulated Luminescence (OSL) to an Archaeological Site Under Water. Master's Thesis. Thesis uri icon

abstract

  • The study of archaeology does not exist without understanding stratigraphy. Terrestrial archaeologists frequently utilize studies in sedimentation to understand a site's stratigraphic history, but many tools have not been translated to underwater sites. Current studies in optically stimulated luminescence (OSL) are proving incorrect many assumptions of a stratigraphy's characteristics by identifying disturbances invisible to the human eye. OSL methodologies allow measurements of the last time quartz was exposed to the sun. The preliminary screening and calibrated screening methods, provide a relative chronology of underwater stratigraphy with the added possibility for absolute dates in the future. The stratigraphy of a shipwreck is often thought of as a time capsule, but even though the artifacts from a shipwreck are of the same time and "context" there is often a horizontal stratigraphy that can aid archaeologists in reconstructing artifact disturbances. OSL was applied to marine sediment samples and cores from Maroni Tsaroukkas, Cyprus to understand patterns of sediment movement, environmental changes, and to test the application of the portable OSL reader on shallow sites (less than 6.0 m depth). Preliminary screening by means of the portable OSL reader provided the expected results. Samples could be distinguished by high, moderate and low OSL signals, which in turn determined which to bring forward to more intensive processing for calibrated results. Comparisons between data from the screenings made it possible to identify which artifacts had moved recently, and areas of sand accumulation. Finally, initial stratigraphic conclusions determined that the sand on site is being thoroughly bleached, and the accumulation and erosion of silt changes drastically between the northwest and southeast sectors of the site.

publication date

  • August 2020