Dynamics of Indian Ocean slavery revealed through isotopic data from the colonial era Cobern Street Burial site, Cape Town, South Africa (1750-1827)

The Dutch East India Company (VOC) intended the Cape of Good Hope to be a refreshment stop for ships travelling between the Netherlands and its eastern colonies. The indigenous Khoisan, however, did not constitute an adequate workforce, therefore the VOC imported slaves from East Africa, Madagascar and Asia to expand the workforce. Cape Town became a cosmopolitan settlement with different categories of people, amongst them a non-European underclass that consisted of slaves, exiles, convicts and free-blacks. This study integrated new strontium isotope data with carbon and nitrogen isotope results from an 18 th -19 th century burial ground at Cobern Street, Cape Town, to identify non-European forced migrants to the Cape. The aim of the study was to elucidate individual mobility patterns, the age at which the forced migration took place and, if possible, geographical provenance. Using three proxies, 87 Sr/ 86 Sr, δ 13 C dentine and the presence of dental modifications, a majority (54.5%) of the individuals were found to be born non-locally. In addition, the 87 Sr/ 86 Sr data suggested that the non-locally born men came from more diverse geographic origins than the migrant women. Possible provenances were suggested for two individuals. These results contribute to an improved understanding of the dynamics of slave trading in the Indian Ocean world

Comparison of strontium isotope ratios in Mexican human hair and tap water as provenance indicators

Deceased undocumented border crossers are some of the most difficult individuals to identify due to the inability to narrow down the region of origin and therefore to obtain family reference samples for DNA comparison. The isotopic compositions of various body tissues have been demonstrated to be useful biomarkers for tracking locations and movements to aid in the identification of human remains. This study closes the large spatial gap of available 87Sr/86Sr ratios from North America in tap water and presents the first 87Sr/86Sr human tissue-based ratios from Mexico. The 101 hair samples from 32 locations in Mexico range in 87Sr/86Sr ratios from 0.70424 to 0.71613 (ΔSrmax–min = 0.01189). Furthermore, 151 tap water samples from 51 locations range between 0.70404 to 0.71385 (ΔSrmax–min = 0.00981). Overall, small variations in the hair and tap water samples collected from individual locations were recorded (ΔSrmax–min = 0.00041 and 0.00034 respectively). Despite the fact that Mexico is one of the largest bottled water consumers in the world, the 87Sr/86Sr ratios of human hair and tap water correlated strongly (R2 = 0.87 for location averages and R2 = 0.80 when using individual data points). These data represent a valuable resource for identifying the provenance of human remains

Investigating seasonal mobility in Irish giant deer Megaloceros giganteus (Blumenbach, 1799) through strontium isotope (87Sr/86Sr) analysis

Giant deer Megaloceros giganteus (Blumenbach, 1799) fossils are commonly found in Lateglacial deposits throughout Ireland. While their migrational behaviour has been suggested, it has never been researched. We hypothesise that giant deer underwent seasonal migrations, specifically during Late Pleistocene cold periods as a behavioural adaptation. Giant deer required a high nutrient uptake and were maladapted to the cold‐dry steppe of the Pleistocene glacials. Migration allowed for optimal nutrient uptake during summer, while avoiding the harsh winter conditions of the glacials by moving to sheltered, low‐lying areas. In this study strontium isotope analysis (87Sr/86Sr) of sequentially sampled dental enamel is conducted for the first time on giant deer that were previously sampled in the same manner for δ13C and δ18O, allowing correlations between the isotope data sets. One specimen from Ballybetagh, Dublin generated results indicating seasonal mobility behaviour. This individual was perhaps pushed to migrate at the Younger Dryas stadial onset as the vegetation giant deer depended on disappeared in Ireland. Adaptive mobility behaviour in response to climate was perhaps imperative to their survival through previous glacial periods, but other Eurasian populations would need to be analysed to make such a general conclusion

Bodemkundig onderzoek van twee mogelijke Bronstijd inhumaties te Malden

Projectnr.: 2009-05

Assessing the preservation of biogenic strontium isotope ratios (87Sr/86Sr) in the pars petrosa ossis temporalis of unburnt human skeletal remains: A case study from Saba

Rationale: Strontium isotope (87Sr/86Sr) analysis of skeletal remains has become a powerful tool in archaeological studies of human migration and mobility. Owing to its resistance to post-mortem alteration, dental enamel is the preferred sampling material used for 87Sr/86Sr analysis in bioarchaeological provenance research, although recent studies have demonstrated that cremated bone is also generally resistant to diagenesis. This paper presents the results of a pilot study exploring the potential of unburnt petrous bone (pars petrosa) as a reservoir of biogenic (diagenetically unaltered) strontium, as the otic capsule or bony labyrinth within the petrous bone is extremely dense and is thought to be unable to remodel after early childhood, potentially providing an alternative for dental enamel. Methods: From an individual from a colonial-era (18th century) site on the island of Saba in the Caribbean for whom previous enamel 87Sr/86Sr results had indicated non-local origins, multiple locations (n = 4) on the petrous were sampled and measured for strontium isotope composition. Saba (13 km2) has been extensively mapped for baseline strontium isotopes (n = 50) with 87Sr/86Sr varying from ca 0.7065 to 0.7090, whereas enamel 87Sr/86Sr (n = 3) ranged from 0.7104 to 0.7112. Results: All four petrous 87Sr/86Sr ratios (0.7111–0.7122) are consistently and considerably higher than the local bioavailable range, and very similar to the enamel 87Sr/86Sr. These results provide initial evidence that unburnt petrous bones may preserve biogenic strontium, at least in this specific burial context. Conclusions: While more research in diverse burial conditions is needed to validate this observation, if confirmed, it would have broader implications for sample selection strategies in bioarchaeological studies using the strontium isotope method

Assessing the preservation of biogenic strontium isotope ratios (⁸⁷Sr/⁸⁶Sr) in the pars petrosa ossis temporalis of unburnt human skeletal remains: A case study from Saba

RATIONALE: Strontium isotope ((87)Sr/(86)Sr) analysis of skeletal remains has become a powerful tool in archaeological studies of human migration and mobility. Owing to its resistance to post‐mortem alteration, dental enamel is the preferred sampling material used for (87)Sr/(86)Sr analysis in bioarchaeological provenance research, although recent studies have demonstrated that cremated bone is also generally resistant to diagenesis. This paper presents the results of a pilot study exploring the potential of unburnt petrous bone (pars petrosa) as a reservoir of biogenic (diagenetically unaltered) strontium, as the otic capsule or bony labyrinth within the petrous bone is extremely dense and is thought to be unable to remodel after early childhood, potentially providing an alternative for dental enamel. METHODS: From an individual from a colonial‐era (18th century) site on the island of Saba in the Caribbean for whom previous enamel (87)Sr/(86)Sr results had indicated non‐local origins, multiple locations (n = 4) on the petrous were sampled and measured for strontium isotope composition. Saba (13 km(2)) has been extensively mapped for baseline strontium isotopes (n = 50) with (87)Sr/(86)Sr varying from ca 0.7065 to 0.7090, whereas enamel (87)Sr/(86)Sr (n = 3) ranged from 0.7104 to 0.7112. RESULTS: All four petrous (87)Sr/(86)Sr ratios (0.7111–0.7122) are consistently and considerably higher than the local bioavailable range, and very similar to the enamel (87)Sr/(86)Sr. These results provide initial evidence that unburnt petrous bones may preserve biogenic strontium, at least in this specific burial context. CONCLUSIONS: While more research in diverse burial conditions is needed to validate this observation, if confirmed, it would have broader implications for sample selection strategies in bioarchaeological studies using the strontium isotope method

An isotopic perspective on the socio-economic significance of livestock in Bronze Age West-Frisia, the Netherlands (2000–800 BCE)

The Bronze Age is increasingly characterised as a period in which the search for and trade in metals dominates mobility and exchange in Europe. Chiefs travelled the lands and seas and dominated the acquisition and possession of critical resources. Most research focuses on the provenance and distribution of metals and on the mobility of people. Yet, the mobility of one the most obvious sources of social and economic wealth in the Bronze Age has got little attention: livestock. This study explores the possible social role of livestock of cattle and sheep, both in the household sphere and in the sphere of exchange as a means of ‘connecting people’. Here, strontium isotope data are presented from 58 cattle and sheep from settlement contexts from Bronze Age West-Frisia (2000–800 BCE), the Netherlands, with the aim to gain an isotopic perspective on the socio-economic significance of livestock. The data provide evidence for long-distance trade or exchange of livestock. Besides their monetary value, we suggest that livestock, and in particular cattle, may have been perceived as equal to people in terms of labour and production and as members of the household. Their mobility and exchange therefore signal more than just economic trade, it signals a social practice. By changing our perspective towards the social ideology of farming life, we will move closer to understanding Bronze Age societies in more diverse and inclusive ways. Research into livestock mobility is therefore considered fundamental for a more diverse understanding of Bronze Age farming life

Sickly slaves, soldiers and sailors. Contextualising the Cape's 18th–19th century Green Point burials through isotope investigation

Strontium isotope data of multiple dental enamel samples, and carbon and nitrogen isotope data of dentine and bone collagen samples from 27 individuals excavated from the mid-18th to mid-19th century Victoria & Albert Marina Residence paupers burial ground in the vicinity of Green Point, Cape Town, provide information about the Indian Ocean slave trade and the experience of the economic underclass at the post-creolisation colonial Cape. Based on childhood diets, and/or the presence of dental modifications, and/or non-local 87Sr/86Sr values, 17 individuals (63%) were identified as non-local. Relatively high δ15Ncancellous values (mean 14‰) compared to individuals from contemporaneous burials (mean 12‰) suggest increased exploitation of marine resources, the consumption of salted meat and fish and/or peri-mortem nutritional and/or water stress in the economic underclass population. The latter scenario lends support to the interpretation that the burial site is linked to the Old Somerset hospital (1818–1845) and perhaps the Dutch East India Company (VOC) hospital (1697–1786) that catered to the highly diverse and mobile lower rungs of VOC society, comprising slaves, soldiers and sailors. The bioarchaeological data are also consistent with an alternate but not mutually exclusive hypothesis; that the population turned to a more affordable protein source after emancipation. These data demonstrate that a bioarchaeological approach to burial sites can illuminate social nuances and in this case make the precarious existence of the Cape economic underclass more tangible

A triple isotope approach (Sr-O-C) to assess human mobility dynamics in the Lower Germanic limes borderscape (40–470 CE)

The intention of the Roman administration to develop the Lower Germanic limes region into a military zone must have been a catalyst for (long-distance) human and faunal mobility in the course of the 1st century CE. A triple isotope approach (Sr-O-C) has been used on a total of 21 cremations (bone and pars petrosa) and 21 inhumations (dental elements) from the Dutch Lower Germanic limes borderscape region to study the demographic dynamics between 150 and 500 CE. The dental enamel 87Sr/86Sr range from 0.7086 to 0.7158. The variability in Sr within the cremated remains is more limited: 0.7089 to 0.7103. The δ18OPDB data range from −7.6 ‰ to −4.3 ‰. All but one individual dating to the Early and Middle Roman period exhibit Sr ratios that are consistent with the expected local (0.7088–0.7092) or regional (up to ± 0.7110) 87Sr/86Sr signature. The population dynamics drastically change in the subsequent Late Roman period. Fifty percent (6/12) of the investigated Late Roman population (partially) spent part of their childhood away from the Dutch river system or even the Batavian civitas. The cremated long bone 87Sr/86Sr possibly point towards residential stability during the last few years of life: all data are compatible with the expected regional Sr signature. The δ13CPDB data vary between −16.0 ‰ and −8.7 ‰: the latter was indicative of a diet rich in C4 food, which was not a staple in the Roman diet in the Lower Germanic limes region. Although more research is essential to better understand the population dynamics in the limes borderscape, it is clear that the isotope data reflect the political-military status of the Lower Germanic limes region, especially during the transition to a militarized zone in the later Roman period. Identifying possible regions of provenance is a challenge. Another proxy for provenance, namely the cultural artefacts associated with the excavated people, did not show a specific relationship between cultural background and geographical origin

Isotopic analysis of formula milk reveals potential challenges in geolocating bottle-fed babies

Abstract In forensic investigations involving the identification of unknown deceased individuals, isotope analysis can provide valuable provenance information. This is especially pertinent when primary identifiers (i.e., DNA, dactyloscopy, etc.) fail to yield matches. The isotopic composition of human tissues is linked to that of the food consumed, potentially allowing the identification of regions of origin. However, the isotopic composition of deceased newborns and infants fed with milk formula may be influenced by that of the prepared milk. The findings contribute towards the possibility to isotopically identify bottle-fed infants. More importantly, the data convincingly show that the Sr isotope composition of the prepared milk is determined by that of the formula and not the (local) tap water, thereby limiting the potential of Sr isotope analysis for determining the geological or geographical origin in formula-fed babies in medico-legal cases