Stephen J. Dockrill

Organic geochemical evidence for the origin of ancient anthropogenic soil deposits at Tofts Ness, Sanday, Orkney

Lipid biomarker components of soils constituting three Orcadian archaeological fossil soil profiles were analysed. The combined assessment of lipid distributional and compound specific stable carbon isotope data enabled the identification of grass turves as the most probable material used in the formation of the anthropogenic soil deposits. Appraisal of 5β-stanol components indicated a faecal input to one of the soils which, on considering distributional evidence, was ascribed a human/porcine origin. Additional study of polar bile acids from this profile revealed a distribution exhibiting a predominance of deoxycholic acid indicating the primary faecal input to be mainly derived from humans although the minor occurrence of hyodeoxycholic acid, a characteristic component of pig faeces, attested to a limited porcine input.

Interpreting early land management through compound specific stable isotope analyses of archaeological soils.

Compound specific stable isotope analyses of managed soils using isotope ratio mass spectrometry have been undertaken as a means of determining early land use practices. delta (15)N amino acid signals demonstrate differences between manured grassland, unmanured grassland and continuous cereal cultivation under long-term experimental land use control conditions, with delta (15)N in hydrophobic amino acids providing the most distinctive signals. Analysis of early modern/medieval and of Bronze age anthropogenic soils from Orkney demonstrates that such signals are retained in archaeological contexts. delta (13)C analyses of n- alkanoic acid components of the fossil, Bronze Age, anthropogenic soils suggest a major terrestrial input to these soils, with uniform composition of formation materials. Surficial soils demonstrate the assimilation of isotopically lighter carbon, providing a means of assessing the mobility of the n- alkanoic acids within soils and sediments. Copyright 1999 John Wiley & Sons, Ltd.

Strategic and Sporadic Marine Consumption at the Onset of the Neolithic: Increasing Temporal Resolution in the Isotope Evidence

Stable isotope analysis has provided crucial new insights into dietary change at the Neolithic transition in north-west Europe, indicating an unexpectedly sudden and radical shift from marine to terrestrial resources in coastal and island locations. Investigations of early Neolithic skeletal material from Sumburgh on Shetland, at the far-flung margins of the Neolithic world, suggest that this general pattern may mask significant subtle detail. Analysis of juvenile dentine reveals the consumption of marine foods on an occasional basis. This suggests that marine foods may have been consumed as a crucial supplementary resource in times of famine, when the newly introduced cereal crops failed to cope with the demanding climate of Shetland. This isotopic evidence is consistent with the presence of marine food debris in contemporary middens. The occasional and contingent nature of marine food consumption underlines how, even on Shetland, the shift from marine to terrestrial diet was a key element in the Neolithic transition.

The identification of prehistoric anthropogenic soils in the northern isles using an integrated sampling methodology

An integrated methodology has been developed using magnetic susceptibility, soil phosphate analysis and soil micromorphology to identify early arable soils in the Northern Isles. These techniques are used in the examination of a series of buried soils dating from the Neolithic to the early Iron Age from Tofts Ness, Sanday, Orkney and a Bronze Age context from South Nesting, Shetland. Magnetic susceptibility has enabled the identification of manure-enhanced soils, and detailed evidence for both cultivation and the nature of the enhancement is provided by the analysis of soil phosphate levesl and soil micromorphology. The identification and study of these soils has led to an insight on prehistoric infield manuring practices and a greater understanding of early land management strategies.

The potential for dating the Old Scatness site, Shetland, by optically stimulated luminescence

A series of deposits from the agricultural infield of the multiperiod settlement mound, Old Scatness, were investigated for their potential to yield optically stimulated luminescence dates. Luminescence properties of quartz grains were found to vary through the sequence, but dates were successfully obtained from five deposits, including anthropogenic soils, windblown sands and sands within midden deposits. Single-aliquot equivalent dose measurement was found to be the most appropriate method for dating the deposits. The OSL dates obtained accorded well with the dates provided by archaeological evidence and included the post-medieval, Iron Age, Bronze Age and Neolithic periods of Shetland, while a substantial midden was dated to the Bronze/Iron Age transition.

Sustainability and Resilience in Prehistoric North Atlantic Britain: The Importance of a Mixed Paleoeconomic System

Abstract The two archipelagos of Orkney and Shetland, which form the Northern Isles of Britain, are an active focus of archaeological research. The rich Neolithic heritage of Orkney has been acknowledged by the granting of World Heritage status. Although set in both a biogeographically peripheral position and within what may be considered to be marginal landscapes, these North Atlantic islands have a large number of settlement sites with long occupational sequences, often stretching from the Neolithic to the Late Iron Age or into the Norse period. The mixed paleoeconomic strategy presented by three of these settlements—Tofts Ness, Sanday, Orkney (excavated 1985–1988); the Iron Age sequences at Old Scatness, Shetland (excavated 1995–2006); and Late Neolithic and Bronze Age cultivated middens from Jarlshof, Shetland (investigated in 2004)—provide the core of the evidence discussed within this paper (the radiocarbon chronologies for the key sequences from these three sites are provided as Appendix 1). The role of the prehistoric paleoeconomy is argued to be of central importance in the longevity of these settlements. In particular, barley production is evidenced on all three sites by the plant macrofossils and by the human investment in the creation and management of manured soils, providing an infield area around the settlement. This paper focuses on the identification of these anthropogenic soils in the archaeological record. The investment in and management of these arable soils provides clear evidence for resource creation on all three sites. It is argued that these soils were a crucial resource that was necessary to support intensive barley cultivation. The intensive management implied by the presence of these soils is seen as a catalyst for sedentary living and sustainability within a marginal landscape. The evidence also demonstrates the continuity of agricultural practice from the Neolithic to the Iron Age together with the social dynamics that such a practice generates. This paper is in two parts: the first section examines in detail the evidence for the presence of anthropogenic soils and the mixed economic strategies for the Neolithic and Early Bronze Age presented by the evidence from Tofts Ness and Jarlshof. The evidence for the continuity of this intensive strategy of soil management is seen from the later evidence of the Bronze Age and Early Iron Age at Tofts Ness and the Middle Iron Age evidence at Old Scatness. The second part of the paper examines the importance of these soils as an inherited resource within the Neolithic and Early Bronze Age paleoeconomic system. Two models are presented. The first examines the cyclic importance of human creation and maintenance of small arable plots to high barley production yields and therefore to site viability, and the effect this has within a mixed resource system in providing settlement viability through time. The second explores the theoretical land and seascape that would provide this mixed resource base.

Magnetic moments in prehistory: integrating magnetic measurements with other archaeological data from the Scatness Multiperiod Settlement

Many types of human activity affect the magnetic properties of the geological materials on which they occur. By integrating measurements of these magnetic properties, such as susceptibility, viscosity, gradiometry and archaeomagnetic data, with other archaeological data, it is possible to answer detailed archaeological questions about such activities. The potential of the close integration of magnetic measurements with ongoing archaeological excavation is illustrated in this paper by discussion of studies during the 1995–1997 excavation of a multiperiod settlement mound at Scatness, Shetland. This site is ideal for an investigation of this nature, as it contains over 4 m of stratified archaeological deposits. These represent an occupational sequence spanning several millennia, from Bronze Age cultivated soils; through the Iron Age, represented by a broch and later wheelhouse complex; to the Pictish and Viking period. This paper focuses on three specific types of context: (i) hearths and burnt areas—using magnetic remanence and susceptibility to determine date and function; (ii) midden deposits—using susceptibility, in combination with chemical and environmental evidence, to determine source material and formation processes; (iii) soils—using susceptibility, in combination with environmental and soil micromorphological evidence, to detect and characterise anthropogenic enhancement of soils. These examples demonstrate that, when combined with other archaeological information, the evidence of human activity retained in magnetic properties can prove a valuable tool for archaeological interpretation. Copyright