The soil as a source material in archaeology: Theoretical considerations and pragmatic applications

Abstract

This thesis deals with questions on various applications using soils and sediments as sources of information in archaeological research. Human environmental impact on soils and sediments, in terms of pollution, is a well known phenomenon as the industrialisation intensified during historical times and onwards and has left strong pollutive marks. However, humans have always accumulated or emitted matter and various compounds in connection to their habitats for subsistence, but these earlier traces are not always detectable, depending on soil and sediment state of preservation. Bioessential elements are intimately linked to humans and their dwellings and especially phosphate has been evident in this respect. It was established already in the 1930s, that even Stone Age settlements could be located through elevated phosphate content in extensive soil phosphate mappings. This thesis is a compilation on results from several sites and excavations from the southern to the northern parts of Sweden. There is a wide variety of soil types and chronological setting in the material, from highly acid podzols to calcareous soils, and sediments dated to Younger Dryas to current top soils. Sites from the Mesolithic, Neolithic, Bronze Age, Early and Late Iron Age and Medieval are all represented. Methods that have been implemented are firstly various forms of analysis in regards to soil phosphate, magnetic susceptibility and organic matter. Furthermore, metal and non-metal elements have been considered, as well as lead isotopes. A multiproxy approach is applied in some examples where biological and chemical data is combined to interpret past events. In this thesis there are also five papers presented. The first paper deals with methodological issues concerning multi-element analyses of various soil samples (off-site to feature) from an archaeological excavation. The second paper is about the possibilities that may be used when analysing the soil organic phosphate in relation to prehistoric agriculture. Paper three and fourth are compilations of large scale contract archaeological project. These papers deal with theoretical, methodological and practical issues concerning environmental archaeology in relation to contract archaeology. Studies on landscape development and erosion are among the cases presented. The last paper deals with a late Mesolithic - early Neolithic settlement in Vuollerim, N. Sweden, and spatial dimensions on the human use of settlement (off-site to onsite) and house floors (intra-site), are discussed.