Colm Donnelly’s research while affiliated with Queen's University Belfast and other places

Current methodologies for radiocarbon dating of mortars typically use mechanical and chemical separation to isolate fractions of carbon dioxide from suitable lime binder carbonates. These methods have a moderate frequency of success, but difficulties are often encountered with (a) secondary crystallisation, (b) the presence of incompletely burnt limestone or limestone aggregate, and (c) more complex hydraulic mortars (e.g. pozzolana or cocciopesto mortars). An alternative approach to isolating CO2 from mortar involves thermal decomposition of the sample. A new ramped pyroxidation (RPO) facility has recently been constructed at the ¹⁴CHRONO Centre. In RPO, samples are incrementally heated, with CO2 produced as the sample undergoes thermal decomposition in the presence (oxidation) or absence (pyrolysis) of oxygen. The CO2 evolved from different temperature fraction are collected cryogenically and radiocarbon dated. This method was applied to several lime mortars with expected ages to investigate if CO2 fractions only associated with the setting of the lime binder could be isolated. For all samples tested, positive results were obtained. All but the first of six CO2 fraction taken during the earlier stages of thermal decomposition were in statistical agreement and could be combined to provide an age that was in excellent agreement with the expected ages (for an Irish medieval round tower, and for a Finnish medieval castle and church). The lowest temperature fraction, not in statistical agreement, is significantly earlier and attributed to contamination from charcoal or coke from lime production. Positive results were also obtained from a piece of mortar that had undergone no pre-treatment. Modelling examining the potential of RPO to isolate lime binder CO2 fractions, where either limestone (or incompletely burnt limestone) or secondary re-crystallised calcite are present as contaminants, further demonstrate the suitability of the approach.

Investigations were carried out to establish the chronology of a building from the city of Derry, Northern Ireland. The date of this structure, previously assumed to be a 17th century windmill, was examined by application of radiocarbon dating to the lime mortar. Multiple sample preparation methods (cryo-breaking, mechanical, suspension) were used to isolate a series of lime binder fractions of different grain sizes. Combined with sequential dissolution and subsequent radiocarbon dating this permitted a) the presence of multiple carbonate components to be identified and, b) aided by inter-comparison of the dissolution profiles and the presence of well-defined plateaus in the age profiles, those components and dates associated with the building’s construction to be resolved. Interpretation of the results was further enhanced by assessing the efficacy of preparations methods through application of particle size analysis, x-ray diffraction, thermogravimetric analysis and Fourier transform infrared spectroscopy. This work revealed that the building can now be recognized as the remains of a mid to late 13th century Irish round tower and, as such, the only building surviving from the Derry’s Medieval monastic era, therefore making it of great cultural and historical significance.

This study investigates the nature of diet in a predominantly Late Medieval Gaelic Irish skeletal population and explores whether any sex-based and/or age differences were evident in the population. A smaller sub-sample was also examined to determine whether there was any evidence for dietary change over time between the Early Medieval (c.700–c.1200) and Late Medieval periods (c.1200–c.1600). The dietary evidence was derived using a multiproxy approach that combined information from dental palaeopathology (n = 356 adults) and analysis of carbon (δ¹³C) and nitrogen (δ¹⁵N) stable isotope compositions (n = 72 individuals). A higher proportion of females were affected by carious lesions when compared to males. This is possibly suggestive of differing levels of carbohydrate consumption between the sexes, although other factors such as eating habits, and genetic and physiological differences may also have influenced the patterns in the data. The isotopic values indicated that both sexes were consuming similar amounts and types (marine vs. terrestrial) of dietary protein. Elevated δ¹⁵N indicated breastfeeding among the youngest in society but, once children had been weaned, the dietary protein was isotopically similar across the different age categories. Among a smaller radiocarbon-dated sub-sample (n = 37), there was an increase in both the percentage of individuals affected by dental caries and the percentage of teeth affected by dental caries between the Early Medieval and Late Medieval periods. This increase may indicate a greater inclusion of plant-based carbohydrates, such as cereals, in the diet over time, although it may also reflect the younger age distribution of the Early Medieval sample. Interpretations for each of these patterns are discussed with reference to the historical and archaeological evidence. Multiproxy palaeodietary studies for Medieval Ireland are limited and this is the first substantial study of evidence derived from both dental palaeopathology and stable isotope analysis.

Lowell is considered as the birthplace of the industrial revolution in the early nineteenth-century United States. Originating in 1822, the new textile factories harnessed the waters of the Merrimack River using a system of canals, dug and maintained by laborers. While this work employed many local Yankees, it also attracted groups of emigrant Irish workers. Grave memorials are a valuable source of information concerning religious and ethnic identity and an analysis of the slate headstones contained within Yard One of St Patrick’s Cemetery, opened in 1832, provides insight into the mindset of this migrant community. The headstones evolved from contemporary Yankee memorials but incorporated Roman Catholic imagery, while the inclusion of shamrocks and details of place of origin on certain memorials attests to a strong sense of Irish identity. The blatant display of such features at a time of ethnic and religious sectarian tensions in Massachusetts demonstrates the confidence that the Irish had of their place in the new industrial town.

Unlike other social sciences, the archaeological discipline has been lacking a theoretical framework to discuss the mechanism of migration. Traditionally, patterns of population movements were denoted from material culture and interpreted within the context of ethnicity and the diffusion of ideas without considering underlying processes and incentives, despite active consideration of these issues by geographers and sociologists. It was not until the 1990s that a more integrated archaeological discussion on the various stimuli, influences, and mechanisms of why people choose to migrate was beginning to evolve. Since then, the debate on migration in archaeology has not only reflected on patterns of cultural and technological change but also increasingly on aspects of identity and self-realization; both in terms of how migrants themselves adapt and adjust to their new home environment, and how the host-communities themselves respond and interact with newcomers. Using four case studies, the current paper proposes a new theoretical model for how to assess patterns of group migrations. This new model considers the respective mode of agency related to both the intention and size of the group. “Very High and High Group Agency” represent situations where the migrant group is at a technological and quantitative advantage to the host community, while “Medium and Low Group Agency” represent situations where the newcomers are forced to respond to their new environment through adaptation and adjustment to their local host community.

Victoria L. McAlister. 2019. The Irish tower house: society, economy and environment, c. 1300–1650. Manchester: Manchester University Press; 978-1-5261-2123-3 hardback £80. - Colm J. Donnelly

Lowell, Massachusetts, is considered as the birthplace of the industrial revolution in the United States. Established in 1822 by a group of Bostonian entrepreneurs, the new textile factories harnessed the Merrimack River to power their waterwheels using a system of canals. This work attracted groups of emigrant Irish workers from Boston, a process that continued into the middle of the century, particularly in the wake of the Great Irish Famine (1845–1852). We are fortunate that two volumes known as The Hanavor Burial Records exist that provide a window into the lives and deaths of the early Irish settlers in Lowell. Some 1450 entries dating to the period between 1849 and 1865 provide details of the occupation of the deceased. This study focuses on Irish pre-teen and teenage workers; their age-at-death profile, the nature of the work they undertook, and the causes of their deaths are examined.

The nature of burial practices relating to children within formal ecclesiastical burial grounds in the period from the seventeenth century to the nineteenth century has, to date, been largely ignored by archaeologists. Even a preliminary survey of such memorials, however, indicates that gravestones erected in the memory of children form a substantial component of the overall corpus of memorials within individual graveyards or cemeteries. A child from a wealthy background might be buried with an elaborately inscribed gravestone, while others were buried anonymously within their family plot, with only a brief reference to their short lives recorded on the memorial. In contrast, many un-named victims of epidemics or famine were buried in common pits, whilst unbaptised children denied burial in consecrated ground were laid to rest in the local children's burial ground or cillín, without formal burial rites by the Roman Catholic church. This study examines the commemoration of children in four case study graveyards in the north of Ireland which date to between the later seventeenth century and the end of the nineteenth century. A survey of the number of memorials and the inscriptions they carry enables a more complete picture of the lives and deaths of the children they commemorate to become apparent.

Reburial of human remains and concerns regarding pathogens and pollution prompted the search for, and assessment of, a 156-year-old graveyard. To locate this graveyard, historic and anecdotal information was compared to landscape interpretation from aerial photography. To assess and map the contents, surface collapses, metal detector indications, and ground-penetrating radar (GPR) were used. Some 170 anomalies compatible with burials were identified on 200 MHz GPR data, 84 of which coincided with surface collapses, suggesting both noncollapsed ground, subsequent infill, and multiple inhumations. The graveyard was possibly split into Roman Catholic plots with multiple inhumations; Protestant plots; and a kileen, or graveyard for the unbaptized (often children). The work serves as one approach to the location and mapping of recent and historic unmarked graves.