Prehistoric burnt mound archaeology in Ireland

It is apparent from the widespread distribution of burnt mounds that Ireland was the most prolific user of pyrolithic technology in Bronze Age Europe. Even though burnt mounds are the most common prehistoric site type in Ireland, they have not received the same level of research as other prehistoric sites. This is primarily due to the paucity of artefact finds and the unspectacular nature of the archaeological remains, compounded by the absence of an appropriate research framework. Due to the widespread use of the technology and the various applications of hot water, narratives related to these sites have revolved around discussions of age and function. This has resulted in a generalised classification, where the term ‘fulacht fia’ covers several site types that have similar features but differing functions and age. The study presents a re-evaluation of fulachtaí fia in light of some 1000 sites excavated in Ireland. This is the most comprehensive study undertaken on the use of pyrolithic technology in prehistoric Ireland, dealing with different aspects of site function, chronology, social role and cultural context. A number of key areas have been identified in relation to our understanding of these sites. Previous investigations of burnt mounds have provided little information on the temporality of individual sites. It has been established that appropriate sampling strategies can provide important information about the formation of individual sites, their relationships to each other and to other monuments in the same cultural landscape. The evidence suggests that considerable caution should be exercised with regard to certain single radiometric dates from burnt stone deposits, based on the degree of certainty of the dated sample and its association with pyrolithic activity. Previously regarded as Bronze Age in date, there are now numerous examples of pyrolithic-type processes in earlier contexts, with the origins of the water-boiling phenomenon now considered to be Early Neolithic. A review of recent excavation evidence provides new insights into the use of pyrolithic technology for cooking. This is based on the discovery of faunal remains at several sites, combined with insights gained through experimental studies. The model proposed here is of open-air communal feasting and food sharing hosted by small family groups, as a medium for social bonding and the construction of community. It is also argued that if cooking was the primary activity taken place at these sites, this should not be viewed as a mundane functional activity, but rather one that actively contributed to the constitution of social relations. The formality of the technology is also supported by the presence of possible specialised structures, some of which were used for cooking/feasting while others were for ritualised sweat-bathing. The duration and frequency of activities associated with burnt mounds and the opportunities they provided for social interaction suggest that these sites contributed some familiar frames of reference to contemporary discourse.

Aerosol properties associated with air masses arriving into the North East Atlantic during the 2008 Mace Head EUCAARI intensive observing period: an overview

As part of the EUCAARI Intensive Observing Period, a 4-week campaign to measure aerosol physical, chemical and optical properties, atmospheric structure, and cloud microphysics was conducted from mid-May to mid-June, 2008 at the Mace Head Atmospheric Research Station, located at the interface of Western Europe and the N. E. Atlantic and centered on the west Irish coastline. During the campaign, continental air masses comprising both young and aged continental plumes were encountered, along with polar, Arctic and tropical air masses. Polluted-continental aerosol concentrations were of the order of 3000 cm(-3), while background marine air aerosol concentrations were between 400-600 cm(-3). The highest marine air concentrations occurred in polar air masses in which a 15 nm nucleation mode, with concentration of 1100 cm(-3), was observed and attributed to open ocean particle formation. Continental air submicron chemical composition (excluding refractory sea salt) was dominated by organic matter, closely followed by sulphate mass. Although the concentrations and size distribution spectral shape were almost identical for the young and aged continental cases, hygroscopic growth factors (GF) and cloud condensation nuclei (CCN) to total condensation nuclei (CN) concentration ratios were significantly less in the younger pollution plume, indicating a more oxidized organic component to the aged continental plume. The difference in chemical composition and hygroscopic growth factor appear to result in a 40-50% impact on aerosol scattering coefficients and Aerosol Optical Depth, despite almost identical aerosol microphysical properties in both cases, with the higher values been recorded for the more aged case. For the CCN/CN ratio, the highest ratios were seen in the more age plume. In marine air, sulphate mass dominated the sub-micron component, followed by water soluble organic carbon, which, in turn, was dominated by methanesulphonic acid (MSA). Sulphate concentrations were highest in marine tropical air - even higher than in continental air. MSA was present at twice the concentrations of previously-reported concentrations at the same location and the same season. Both continental and marine air exhibited aerosol GFs significantly less than ammonium sulphate aerosol pointing to a significant organic contribution to all air mass aerosol properties.