Mineral magnetism and archaeology at Galson on the Isle of Lewis, Scotland

Abstract

Coastal erosion is cutting a section through a complex later prehistoric archaeological site at Galson. 168 samples from individual features e.g. middens and hearths, and also from several continuously-sampled vertical profiles were collected from the site. A range of mineral magnetic measurements, including susceptibilities, and laboratory induced remanent magnetisations have been carried out on the samples. The strong magnetic signal of the hearth material can be traced in selected floors and middens giving an indication of the anthropogenic use within the dwellings. The magnetic data also highlight differences between visually similar soils. The variation of susceptibility with temperature, measured at 2cm intervals in a vertical profile through a hearth in one of the dwellings, has revealed two distinct magnetic mineralogies, with varying domain states, possibly reflecting different fuel sources.