Mineral Phases in Burned Salmonid Bone and their Relevance to Studies of Combustion Features
Channel: Recording Archaeology
Date: 19/10/2017

Mineral Phases in Burned Salmonid Bone and their Relevance to Studies of Combustion Features at Northern Hunter-Gatherer Sites

Primarily owing to poor preservation, ichthyoarchaeological evidence is uncommon at hunter-gatherer sites from various regions and timeframes. In particular, the absence of salmonid bones is conspicuous at many ancient sites across the Arctic region. Given ethnoarchaeological observations on discard of meal remains into domestic hearths at fisher camps, this research focuses on the development of heat-related geoarchaeological indicators useful for identifying salmonid fishing economies. Specifically, heat altered bone mineral is explored as a prospective marker for fish remains discarded in domestic hearth contexts. A series of laboratory incineration experiments was used to characterize the mineralogy of burned salmonid vertebrae, in comparison to bones of northern game mammals and birds. Fourier transform infrared spectroscopy and X-ray diffraction distinguished the formation of high quantities of the phosphate mineral beta magnesium tricalcium phosphate at temperatures as low as 600oC exclusively in salmons bones. In other fish, mammal, and bird bones studied this mineral formed only above 800oC. This indicates that the presence of beta magnesium tricalcium phosphate is expected in combustion features at hunter-gatherer salmonid fishing sites. An archaeological case study of a Mid-Holocene hunter-gatherer site located on a salmon migration route in northern Finland is underway. This approach has promise as a new means of further evaluating the temporal, geographic, and cultural scope of salmonid harvesting among northern hunter-gatherers.

Don H. Butler and Ruth Shahack-Gross Laboratory for Sedimentary Archaeology, Department of Maritime Civilizations, University of Haifa, Israel