Carolyn Chenery

Investigating population movement by stable isotope analysis: a report from Britain

Stable isotopes present in local ground water get into peoples teeth before they are 12 years old, and act as a signature to the area where they grew up (and drank the water). In a review of recent work in Britain the authors show the huge potential of this method for detecting population movement – and thus ultimately for investigating questions of migration, exogamy and slavery.

The oxygen isotope relationship between the phosphate and structural carbonate fractions of human bioapatite

RATIONALE Oxygen isotope analysis of archaeological human dental enamel is widely used as a proxy for the drinking water composition (δ(18)O(DW)) of the individual and thus can be used as an indicator of their childhood place of origin. In this paper we demonstrate the robustness of structural carbonate oxygen isotope values (δ(18)O(C)) in bioapatite to preserve the life signal of human tooth enamel by comparing it with phosphate oxygen isotope values (δ(18)O(P)) derived from the same archaeological human tooth enamel samples. METHODS δ(18)O(C) analysis was undertaken on 51 archaeological tooth enamel samples previously analysed for δ(18)O(P) values and strontium isotopes. δ(18)O(C) values were determined on a GV IsoPrime dual inlet mass spectrometer, following a series of methodological tests to assess: (1) The reaction time needed to ensure complete release of CO(2) from structural carbonate in the enamel; (2) The effect of an early pre-treatment with dilute acetic acid to remove diagenetic carbonate; (3) Analytical error; (4) Intra-tooth variation; and (5) Diagenetic alteration. RESULTS This study establishes a direct relationship between δ(18)O(C) and δ(18)O(P) values from human tooth enamel (δ(18)O(P) =  1.0322 × δ(18)O(C) - 9.6849). We have combined this equation with the drinking water equation of Daux et al. (J. Hum. Evol. 2008, 55, 1138) to allow direct calculation of δ(18)O(DW) values from human bioapatite δ(18)O(C) (δ(18)O(DW)  =  1.590 × δ(18)O(C) - 48.634). CONCLUSIONS This is the first comprehensive study of the relationship between the ionic forms of oxygen (phosphate oxygen and structural carbonate) in archaeological human dental enamel. The new equation will allow direct comparison of data produced by the different methods and allow drinking water values to be calculated from structural carbonate data with confidence.

Migration and diversity in Roman Britain: A multidisciplinary approach to the identification of immigrants in Roman York, England

Previous anthropological investigations at Trentholme Drive, in Roman York identified an unusual amount of cranial variation amongst the inhabitants, with some individuals suggested as having originated from the Middle East or North Africa. The current study investigates the validity of this assessment using modern anthropological methods to assess cranial variation in two groups: The Railway and Trentholme Drive. Strontium and oxygen isotope evidence derived from the dentition of 43 of these individuals was combined with the craniometric data to provide information on possible levels of migration and the range of homelands that may be represented. The results of the craniometric analysis indicated that the majority of the York population had European origins, but that 11% of the Trentholme Drive and 12% of The Railway study samples were likely of African decent. Oxygen analysis identified four incomers, three from areas warmer than the UK and one from a cooler or more continental climate. Although based on a relatively small sample of the overall population at York, this multidisciplinary approach made it possible to identify incomers, both men and women, from across the Empire. Evidence for possible second generation migrants was also suggested. The results confirm the presence of a heterogeneous population resident in York and highlight the diversity, rather than the uniformity, of the population in Roman Britain.

The age of Stonehenge

Stonehenge is the icon of British prehistory, and continues to inspire ingenious investigations and interpretations. A current campaign of research, being waged by probably the strongest archaeological team ever assembled, is focused not just on the monument, but on its landscape, its hinterland and the monuments within it. The campaign is still in progress, but the story so far is well worth reporting. Revisiting records of 100 years ago the authors demonstrate that the ambiguous dating of the trilithons, the grand centrepiece of Stonehenge, was based on samples taken from the wrong context, and can now be settled at 2600-2400 cal BC. This means that the trilithons are contemporary with Durrington Walls, near neighbour and Britains largest henge monument. These two monuments, different but complementary, now predate the earliest Beaker burials in Britain – including the famous Amesbury Archer and Boscombe Bowmen, but may already have been receiving Beaker pottery. All this contributes to a new vision of massive monumental development in a period of high European intellectual mobility….

Evidence for mummification in Bronze Age Britain

Ancient Egyptians are thought to have been the only people in the Old World who were practising mummification in the Bronze Age (c. 2200-700 BC). But now a remarkable series of finds from a remote Scottish island indicates that Ancient Britons were performing similar, if less elaborate, practices of bodily preservation. Evidence of mummification is usually limited to a narrow range of arid or frozen environments which are conducive to soft tissue preservation. Mike Parker Pearson and his team show that a combination of microstructural, contextual and AMS 14 C analysis of bone allows the identification of mummification in more temperate and wetter climates where soft tissues and fabrics do not normally survive. Skeletons from Cladh Hallan on South Uist, Western Isles, Scotland were buried several hundred years after death, and the skeletons provide evidence of post mortem manipulation of body parts. Perhaps these practices were widespread in mainland Britain during the Bronze Age.

A summary of strontium and oxygen isotope variation in archaeological human tooth enamel excavated from Britain

This paper presents a compilation of strontium and oxygen isotope data from human tooth enamel that has been produced at NERC Isotope Geosciences Laboratory over the last c.15 years. These many and often small studies are here combined to provide an overview of data from Britain. The strontium isotope composition ranges between 0.7078 and 0.7165 (excluding individuals deemed to be of non-British origin). The median Sr concentration is 84 ppm but there is a vector of increasing Sr concentrations related to seawater strontium isotope composition that is seen in individuals predominantly from the west coast of Scotland attributed to the used of kelp as a fertilizer. The oxygen isotope data is normally distributed with a mean value of 17.7‰ ± 1.4‰ (2SD n = 615). Two sub-populations of local individuals have been identified that provide control groups for human enamel values from the eastern side of Britain where there are lower rainfall levels: 17.2‰ ± 1.3‰, (2SD, n = 83) and western area of Britain where rainfall levels are higher = 18.2‰ ± 1‰, (2SD, n = 40). These data make it possible to make direct comparisons of population means between burial populations and the control dataset to assess commonality of origin.

Modern macaque dietary heterogeneity assessed using stable isotope analysis of hair and bone.

Dietary variability might have been a major factor in the dispersal and subsequent persistence of the genus Macaca in both tropical and temperate areas. Macaques are found from northern Africa to Japan, yet there have been few systematic attempts to compare diets between different modern populations. Here we have taken a direct approach and sampled museum-curated tissues (hair and bone) of Macaca mulatta (rhesus macaques) for carbon and nitrogen stable isotope dietary analyses. Samples from India, Vietnam, and Burma (Myanmar) were taken, representing both tropical and temperate populations. The delta(13)C values obtained from hair show that the temperate macaques, particularly those from Uttar Pradesh, have a delta(13)C signature that indicates at least some use of C(4) resources, while the tropical individuals have a C(3)-based diet. However, delta(13)C values from bone bioapatite indicate a C(3)-based diet for all specimens and they do not show the C(4) usage seen in the hair of some animals, possibly because bone represents a much longer turnover period than that of hair. The results of delta(15)N analyses grouped animals by geographic region of origin, which may be related to local soil nitrogen values. The greatest variation in delta(15)N values was seen in the specimens from Burma, which may be partly due to seasonality, as specimens were collected at different times of year. We also investigated the relationship between the hair, bone collagen, and bone bioapatite delta(13)C results, and found that they are highly correlated, and that one tissue can be used to extrapolate results for another. However, our results also suggest that hair may pick up discrete feeding traces (such as seasonal usage), which are lost when only bone collagen and bioapatite are examined. This has important implications for dietary reconstructions of archaeological and paleontological populations.

Diagenetic effects on the oxygen isotope composition of bones of dinosaurs and other vertebrates recovered from terrestrial and marine sediments

Assessing effects of diagenesis on oxygen isotope composition of bone is essential to its use in reconstructing habitats and lifestyles of ancient vertebrates. These effects are a matter of controversy, particularly in the case of extinct animals such as dinosaurs. To investigate the effects of diagenesis on isotopic composition of fossil bone, bone samples from both marine and terrestrial Campanian sediments from Alberta, Canada, have been analysed. The isotopic compositions of oxygen (δ18OSMOW) were determined in bones sampled from articulated skeletons of exclusively terrestrial animals recovered from the terrestrial Dinosaur Park Formation, and compared with bones from the marine Bearpaw Formation. The articulated skeleton of an exclusively terrestrial dinosaur (hadrosaur) found in marine sediments yielded similar δ18O values for both structural carbonate and phosphate fractions (mean δ18OSMOW values 22.6‰ and 16.9‰, respectively) in bone to marine reptiles (mosasaurs) recovered from the same locality (mean δ18OSMOW values 24.2‰ and 17.3‰, respectively). The isotopic composition of both skeletons recovered from marine sediments was significantly more positive than that of articulated hadrosaur skeletons recovered from contemporaneous terrestrial sediments (mean phosphate δ18OSMOW value 12.9‰), and outside the range of phosphate δ18OSMOW values previously reported for terrestrial dinosaur skeletons (c. 9–14‰). These data suggest that the isotopic composition of oxygen in the phosphate and structural carbonate ions in the bone apatite was altered during diagenesis and can be used for neither palaeoclimate nor physiological reconstruction.

A Lady of York: migration, ethnicity and identity in Roman Britain

Modern methods of analysis applied to cemeteries have often been used in our pages to suggest generalities about mobility and diet. But these same techniques applied to a single individual, together with the grave goods and burial rite, can open a special kind of personal window on the past. Here, the authors of a multidisciplinary project use a combination of scientific techniques to illuminate Roman York, and later Roman history in general, with their image of a glamorous mixed-race woman, in touch with Africa, Christianity, Rome and Yorkshire.

Climate changes in the Atlantic Sector of Antarctica over The Past 500 Years from Ice-Core and Other Evidence

Evidence from ice cores, borehole temperatures, early expeditions and glacier margins is used to identify the major climate trends of the past 500 years in the Antarctic Peninsula region. Apparent conflicts between the different data sources are exposed and causes discussed. Ice-core records from areas influenced by the Weddell Sea appear to be strongly sensitive to ice-edge effects, which can be detected in the profiles of deuterium excess and methane sulphonic acid. The various data now appear to be consistent with a scenario where conditions during the mid-19th century to 1940’s period was fairly cool until the onset of the recent extensive warming in the post-1940’s period. The coldest period of the past 300 years appears to have occurred around 1760–1780, associated with strong disturbances in the atmospheric circulation in the Weddell Sea region. This may be contemporaneous with a rather stronger cold anomaly previously observed at Law Dome and suggested for ice cores recovered elsewhere in East Antarctica.