Rebecca MacRoberts
Universidade de Évora, Laboratório HERCULES, Graduate Student
- Aristotle University of Thessaloniki, School of Chemistry - Archmat (archaeometry and material science applied to cultural heritage), Graduate StudentUniversità degli Studi "La Sapienza" di Roma, Chemistry, Graduate StudentUniversity of the Witwatersrand, Geography, Archaeology and Environmental Studies, Alumnusadd
- Digital Photogrammetry applied to Archaeology, Photogrammetry, Medieval Archaeology, Medieval History, Archaeology, Archaeometry, and 9 moreLandscape Archaeology, portable XRF (PXRF) in Archaeology and Museum Science, 3D Laser Scanning (Archaeology), Archaeological GIS, Archaeological Science, Bioarchaeology, Stable Isotopes, Death and Burial (Archaeology), and Stable Isotopes and Palaeodietedit
Thirteen medieval skeletons excavated from the Museu de Évora (Portugal) cellars were studied through the stable isotopic analysis of carbon and nitrogen ratios in the bones using EA-IRMS (Elemental Analysis - Isotope Ratio Mass... more
Thirteen medieval skeletons excavated from the Museu de Évora (Portugal) cellars were studied through the stable isotopic analysis of carbon and nitrogen ratios in the bones using EA-IRMS (Elemental Analysis - Isotope Ratio Mass Spectrometry) and the trace elements in their tooth enamel and dentine using LA-ICP-MS (Laser Ablation Inductively Coupled Mass Spectrometry) to reconstruct diet and understand social status between and within two distinct populations. Two individuals from the Islamic Period were found to have diets mainly based on C3 plants with some C4 or marine resource influences. The Medieval Christian adults, thought to be an elite order of knights who protected the city after the Reconquest of Portugal, displayed varied diets with mostly C3 plants and high levels of protein, probably marine-based. This supports historical documentation of restricted eating habits within the Order of Évora and also of the diverse origins of the order’s members. The concentrations of Ba and Sr relative to Ca in the tooth enamel were considered as additional paleodietary indicators. The extent of diagenesis was assessed in the bones using ATR-FTIR (Attenuated total reflection- Fourier-transform infrared spectroscopy) to measure crystallinity and collagen content, and collagen quality was assessed by carbon to nitrogen ratios in the elemental analyser. Skeletons from Survey 50 were found to be in a poorer state of preservation than those from the other zones. Diagenetic alteration in the teeth was evaluated with LA-ICP-MS by measuring U and rare earth element (REE) concentrations, and lead ingestion was identified in the enamel of two individual, one being the Muslim adult female and the other a young Medieval Christian adult.
Research Interests:
This project uses the technique of multi-image photogrammetry to capture and document two ceramics from the National Palace at Sintra. The objects were both also subjected to chemical analysis using X-ray fluorescence (XRF) to understand... more
This project uses the technique of multi-image photogrammetry to capture and document two ceramics from the National Palace at Sintra. The objects were both also subjected to chemical analysis using X-ray fluorescence (XRF) to understand the mineralogical composition of the glaze and parts of the surface in different colours. Using both the 3D models and the data from the analysis, an online application was made to display the objects in an interactive and informative way, with the aim of making the information interesting and accessible to researchers as well as the general public. Furthermore, the benefits and limitations of this practice are discussed in the context of how useful it is within the fields of archaeological science and cultural heritage conservation.
The study of stone-walled structures from within the last 1000 years in southern Africa can help archaeologists to understand how the landscape was peopled. The size, spatial distribution and patterns can be representative of societal... more
The study of stone-walled structures from within the last 1000 years in southern Africa can
help archaeologists to understand how the landscape was peopled. The size, spatial
distribution and patterns can be representative of societal changes through time and space,
so classifying these structures can be very beneficial to the research process. Google Earth
and Geographic Information System (GIS) programmes can make the data capture process
easier and more efficient, but when a number of different analysts are involved, there can
be significant variability in their results. By comparing the classification data obtained by
three analysts in the area “Joe 2” in southern Gauteng, it was possible to quantify the interanalyst
variability and also find out where and why it occurred. The quality of Google Earth
imagery noticeably influenced how the analysts outlined and classified the stone-walled
structures. This, along with the subjective decisions of the three analysts when it came to
interpreting and classifying the structures, resulted in significantly high levels of interanalyst
variability. With more intensive training and better use of the resources available,
inter-analyst variability can be drastically reduced so that research results and their
subsequent interpretation are more reliable. As the problem faced by all fields of
archaeology, it deserves better insight and understanding than is currently available.
help archaeologists to understand how the landscape was peopled. The size, spatial
distribution and patterns can be representative of societal changes through time and space,
so classifying these structures can be very beneficial to the research process. Google Earth
and Geographic Information System (GIS) programmes can make the data capture process
easier and more efficient, but when a number of different analysts are involved, there can
be significant variability in their results. By comparing the classification data obtained by
three analysts in the area “Joe 2” in southern Gauteng, it was possible to quantify the interanalyst
variability and also find out where and why it occurred. The quality of Google Earth
imagery noticeably influenced how the analysts outlined and classified the stone-walled
structures. This, along with the subjective decisions of the three analysts when it came to
interpreting and classifying the structures, resulted in significantly high levels of interanalyst
variability. With more intensive training and better use of the resources available,
inter-analyst variability can be drastically reduced so that research results and their
subsequent interpretation are more reliable. As the problem faced by all fields of
archaeology, it deserves better insight and understanding than is currently available.
Research Interests:
The Kingdom of Portugal was established with the help of military-monastic orders, which provided important defence against Muslim armies during the 12th–13th century Christian conquest. While historical sources document the main events... more
The Kingdom of Portugal was established with the help of military-monastic orders, which provided important defence against Muslim armies during the 12th–13th century Christian conquest. While historical sources document the main events of this period, this research seeks to elucidate individual lifestyles and movement, aspects typically absent from written records. A multi-isotopic approach was used on skeletal material from eight Christian and two Muslim burials from Évora, Portugal (11th–13th centuries). Anthropological and archae- ological evidence suggests the Christian adults belonged to the Évora Militia, which we seek to confirm through the reconstructed diet and mobility of these individuals. Stable carbon, nitrogen and sulphur isotopes were measured in bone collagen, and radiogenic strontium, carbonate stable oxygen and apatite stable carbon iso- topes were measured in tooth enamel. Results of the stable oxygen and radiogenic strontium isotopes indicated diverse origins of the Christian population, while at least one individual was local. The Muslim adult was local, as anticipated. The δ13Cen (enamel) values provide evidence of childhood consumption of different cereals (C3 and C4), possibly linked to social status. The δ13Ccol (bone collagen) human values indicated mostly C3 diets with varying inputs of C4, while δ15N reflected high protein intake overall. The mean diet-consumer spacing of this population was compared to other isotopic studies from Medieval Iberia and other European monastic/convent populations. A visible trend emerged in populations that likely followed religious fasting rules, including the Évora Christians. The results of this study indicate that the Order of Évora was composed of members from diverse geographic and possibly social origins, an aspect previously unclear in written sources.
Research Interests:
O projeto FCT TRANSCULTURAL (IF/ 01661/2015 e POCI-01-0145-FEDER-031599), onde este trabalho se insere, desenvolve uma abordagem transdisciplinar para compreensão da organização sócio-económica das populações muçulmanas e cristãs em... more
O projeto FCT TRANSCULTURAL (IF/ 01661/2015 e POCI-01-0145-FEDER-031599), onde este trabalho se insere, desenvolve uma abordagem transdisciplinar para compreensão da organização sócio-económica das populações muçulmanas e cristãs em Portugal Medieval (sécs. XII-XIV), mediante a investigação dos seus hábitos funerários, dieta e mobilidade. Como tal, contribui também para o conhecimento da transição e das relações entre muçulmanos e cristãos no final do Garb Al-Andalus. Os hábitos alimentares e os padrões de mobilidade são arquivados no esqueleto durante o decurso da vida dos indivíduos, através da ingestão de componentes dietéticas, cuja composição química específica depende da natureza e do local de ingestão. A dieta e a mobilidade são investigadas principalmente através de três sistemas isotópicos, carbono, azoto e enxofre, e fornecem informações sobre o tipo de planta ingerida (δ13C), o nível trófico do consumidor (δ15N), e se as proteínas ingeridas provêm de ambiente marinho (δ15N, δ34S) ou dulcícola (δ34S). O presente trabalho centra-se nas urbes medievais de Loulé e Cacela-a-Velha e, mais especificamente, nas necrópoles da Quinta da Boavista (Loulé) e do Poço Antigo (Cacela-a-Velha). A primeira tem utilização almóada, entre os séculos XII e XIII, e a segunda tem utilização cristã, entre os séculos XIII e XIV.
Research Interests:
Call for Applications to EAA 26th Annual Meeting, Budapest, 26-30 August 2020 Theme 5.) Theories and methods in archaeology: interactions between discipline - Session #40: Invisible excavation: archeology and cultural heritage science of organic materials for reconstructing ritual practices and dietmore
Organic materials of plant and animal origin are a great source of information for the detection of changes in dietary habits, rituals, technological practices, trades, and past environmental conditions in different archaeological... more
Organic materials of plant and animal origin are a great source of information for the detection of changes in dietary habits, rituals, technological practices, trades, and past environmental conditions in different archaeological contexts. Since they are more susceptible to decay and biological oxidation, organic materials are not always preserved in their integral state and can be overlooked during archeological excavation. However, this knowledge is not lost, being “hidden” as micro-remains, organic residues, ancient DNA, chemical structures or isotopic ratios. Developing new technologies, cultural heritage science and interdisciplinary approaches, allow the well of information to be unearthed in laboratories, museums and conservation centers. This potential should not be ignored, but encouraged to build a comprehensive mosaic of human diet in the past, as well as to shed a light on the organic materials employed in sacred rituals.
A wide spectrum of papers with a particular emphasis on methodologies and the use of advanced techniques for the analysis and reconstruction of diet and ritualistic behavior, as well as case studies are welcomed. Papers can address but are not limited to the following topics:
- Best strategies and practices employed for sampling, collection, preservation and conservation of organic materials in different archeological contexts
- Existing methodologies and techniques applied to the study of archeological organic materials as well as pioneer lines of research
- The challenges of the recognition and value of organic materials in the archaeological record
- The preventive aspects for organic materials and their identification in the archaeological record
- Reconstruction of human dietary habits in Europe from Prehistory to Modern Times
- Organic materials as evidence for ritualistic behavior
- The social and spiritual aspects mirrored in archeological materials of organic sources
A wide spectrum of papers with a particular emphasis on methodologies and the use of advanced techniques for the analysis and reconstruction of diet and ritualistic behavior, as well as case studies are welcomed. Papers can address but are not limited to the following topics:
- Best strategies and practices employed for sampling, collection, preservation and conservation of organic materials in different archeological contexts
- Existing methodologies and techniques applied to the study of archeological organic materials as well as pioneer lines of research
- The challenges of the recognition and value of organic materials in the archaeological record
- The preventive aspects for organic materials and their identification in the archaeological record
- Reconstruction of human dietary habits in Europe from Prehistory to Modern Times
- Organic materials as evidence for ritualistic behavior
- The social and spiritual aspects mirrored in archeological materials of organic sources