Phosphate as an indicator of occupational intensity at shell midden sites on the central coast of British Columbia

Abstract

This thesis explores phosphate as an indicator of occupational intensity (i.e. as a function of scale and length of occupation) at shell midden sites on the central coast of British Columbia. Despite the prevalence of shell middens in coastal environments world-wide and the long history of elemental analysis in archaeology, shell middens are not routinely investigated for their chemical content. Ongoing research on the British Columbia central coast has shown clear associations between fish bone densities (NISP/L) and site area (m2), which have proven useful for characterizing variability among settlements in the region. This provided the opportunity and essential basis for investigating phosphate. Due to its general abundance, persistence, and established association with human activity, phosphate was expected to reflect previously inferred patterns in occupational intensity, which were based on fish bone density and site area data. Results show clear relationships between phosphate values, fish bone densities, and site area, which speaks to the utility of phosphate as an independent indicator of the relative intensity of residential activity among sites.