Radiocarbon dating of prehistoric hearths in alpine northern Sweden: problems and possibilities

The chronology of prehistoric Sami settlement sites has previously been established by conventional radiocarbon dating of bulk charcoal samples associated with hearths from sunken hut floors (stállo-foundations). Here we present results of a comprehensive dating exercise of stállo-foundations in the alpine area of northern Scandinavia using Accelerator Mass Spectrometry (AMS) radiocarbon dating of charcoal. Over a 3 km² study area, AMS calibrated ages of hearth charcoal from 22 stállo-foundations across 12 sites securely date these features to between cal. AD 640 and AD 1180. Only small variations in age were found between charcoal samples from different areas of a given hearth. Statistical analysis of all the charcoal AMS radiocarbon dates obtained reveals that 12 stállo-foundations across nine sites are contemporaneous and date to the Viking Period (AD 800–AD 1050). The tightly constrained AMS-based chronology of stállo-foundations contrasts with the existing chronology based on conventional radiocarbon analysis, which places these features within a significantly greater time-frame of between AD 600 and AD 1900, with most dates ranging between AD 800 and AD 1350.This discrepancy is likely to result from the necessity of collecting composite hearth charcoal particles, which may originate from different phases of occupation, in order to achieve the required final carbon content for conventional radiocarbon analysis. We argue that the new AMS-based radiocarbon chronology of stállo-foundations presented here supersedes the existing chronology based on conventional (Gas Proportional counting) radiocarbon analysis and we advocate the use of AMS radiocarbon dating in future hearth investigations.     

A Viking Ship Graffito from Kilclief,County Down,Ireland

Deep ploughing near Kilclief, County Down, near the site of an early monastery, disturbed a large quantity of buried stones. One of these displayed a Viking‐type ship with a furled sail. Decorative artwork on the stone suggests an 11th‐century date. The ship displays close similarities to Viking ship graffiti in Viking Dublin and in the Scandinavian homelands. This article describes the decorated stone and suggests that it represents an Irish ship constructed in the Viking style. Documentary sources indicate that ships were being granted by an Irish over‐king to a local king of this area at this time.     

A Late Iron Age Boat‐Grave from Petersdal,Denmark

In 1921 a secondary grave was excavated in a Bronze Age burial‐mound on the island of Amager in the strait of Øresund between Denmark and Sweden. Recently the material was examined in detail and the result is presented here. This grave proved to be one of the few Late Iron Age boat‐graves in South Scandinavia. The boat, only preserved through a pattern of clench‐nails, was 10–12 m long. It contained traces of grave‐goods: sword, spear, riding‐gear, bucket and chest, but no trace of a body survived. The grave is contextually dated to the first half of the 8th century. © 2012 The Author     

The soils of an Iron Age farm site ‐bjellands⊘ynæ, SW Norway

Soil investigations have been carried out at an Iron Age farm site lying under natural vegetation. The soils of the area were mapped and described, and soil samples analysed for pH, organic carbon, total nitrogen, acid‐soluble phosphorus, and available sodium, potassium, calcium and magnesium. Two soil types were distinguished on the mineral soils ‐ Brown Podzolic Soils and Iron Humus Podzols. The former are associated with a higher pH, higher phosphorus contents, and a lower carbon‐nitrogen ratio. These differences arc difficult to explain by natural causes, and arc ascribed to cultivation and manuring of the soil during the occupation of the site.     

Lead Isotope Analysis of Tooth Enamel from a Viking Age Mass Grave in Southern Britain and the Constraints it Places on the Origin of the Individuals

Lead analysis of tooth enamel from individuals recovered from a Viking Age burial pit in southern England provides further evidence for their childhood origins outside Britain. All except one of the men have very low Pb concentrations that exclude anthropogenic Pb exposure. Strontium and oxygen isotope compositions identify a core group of men who have Pb isotope compositions of ²⁰⁸Pb/²⁰⁶Pb = 2.065 ± 0.021 (n = 20, 2SD) that, when compared with data from European soils, appear to exclude a childhood in the Scandinavian countries of Norway, Sweden and Finland, whereas areas of Northern continental Europe cannot be excluded.     

Phenol Formaldehyde Revisited—Novolac Resins for the Treatment of Degraded Archaeological Wood

Archaeological wood is usually severely degraded. The Norwegian Viking Age Oseberg find exemplifies problems arising due to past conservation treatments and the need for new types of preservatives. Phenol formaldehyde (PF) has been investigated as a consolidant for alum‐treated wood. X‐ray tomography has revealed that it is possible to obtain a porous structure inside the wood, ensuring ethical acceptability by allowing re‐treatment. In order to understand the curing mechanics, the kinetics of the initial condensation reaction were elucidated at room temperature. It was found that a second‐order reaction using both phenol and formaldehyde concentrations is the most probable mechanism.     

Metallurgical findings from a Viking Age chieftain’s farm in Iceland

The metalworking, metal import, and use of metal in medieval Iceland is still little understood. When the Scandinavian settlers colonized Iceland in the 9th c. AD, the island was found to contain no useful metal deposits save for bog iron, and the deforestation that followed the settlement resulted in a scarcity of wood. Only in the last decades have archaeological excavations begun to unravel how the first Icelanders dealt with this lack of resources. This paper presents the metallurgical findings from a Viking Age chieftain's farmstead at Hrísbrú in the Mosfell valley, located just outside Iceland’s present-day capital Reykjavik. The excavated metal objects had all been crafted with good workmanship employing technology similar to that used in mainland Scandinavia. However, most excavated metal finds show evidence of re-use, which together with the second-grade metal in some of the objects indicates a shortage of raw material that prompted the Icelandic colonizers to improvise and make do with whatever material was at hand.     

Diatoms as bioindicators of site use: locating turf structures from the Viking Age

Diatoms recovered from archaeological features on a Viking Age farmstead excavation in the Mosfell Valley in southwestern Iceland are utilized as microscopic indicators of turf-based structures. Eroded turf can be difficult to distinguish macroscopically from naturally occurring sediments because turf foundations erode and melt into the landscape over time, leaving minimal evidence of site use. Turf was a principle building component in Iceland until the early 20th century. Turf strips and blocks were harvested from lowlands where organically rich peat and abundant water contributed to the development of bog plants with thick root mats that produced premium turf. Diatoms embedded in turf reflect the ecological conditions of the peat-bog at the time of deposition. Turf was cut from the bog and transported to higher elevations where drainage was more conducive to house construction. Siliceous diatom frustules are resistant to decay and preserve well archaeologically. The presence of diatoms in archaeological sediments is considered a marker of sediment provenience and an indication of human site use and anthropogenic modification of natural substrates. This paper demonstrates how diatom analysis can determine the presence and delimitation of archaeological features otherwise difficult to distinguish with the naked eye.