Geoarchaeology 21 (3)

The creation of anthropic sediments, traditionally referred to under the blanket term midden, through the utilization of settlement waste materials in domestic settlement construction was first recognized during early excavations at the Orcadian Neolithic site of Skara Brae. The authors contend that, prior to the present study, there has been no systematic attempt to identify the nature of these sediments at Skara Brae, whose likely occupation dates between 3100 and 2500 BC, or to assess whether different materials were incorporated into construction or varied with different phases of site formation. The opportunity to begin addressing these issues arose with the location of undisturbed sediment samples held in storage since the last site excavations of 1972--1973. Ten thin sections were manufactured from these samples, representing earlier and later phases of Neolithic settlement at Skara Brae. Observations using thin-section micromorphology, supported by total phosphorus and particle-size distribution analyses, suggest that both earlier and later settlement phases show accumulation of household waste dominated by fuel residues. These wastes may have been used to help stabilize wind-blown sand deposits during the later settlement phases. In addition, the use of clay material tempered with household waste is associated with wall construction. Animal manures are only evident in anthropic deposits on the edge of the main settlement site where composting may have been taking place, and there is no evidence for their use in site construction. The authors conclude by drawing attention to possible diverse uses of anthropic sediments in settlement construction at other Neolithic settlements in Orkney.