image/svg+xml71XIV/1/2023INTERDISCIPLINARIA ARCHAEOLOGICANATURAL SCIENCES IN ARCHAEOLOGYhomepage: http://www.iansa.euLocals or Migrants? Strontium Isotope Analysis of Two North-South Oriented Great Moravian GravesMartina Fojtová1*, Zdeněk Vytlačil2,31Anthropos Institute, Moravian Museum, Zelný trh 6, 659 37 Brno, Czech Republic2Department of Anthropology, National Museum, Václavské náměstí 68, 115 79 Praha1, Czech Republic3Department of Anthropology and Human Genetics, Faculty of Science, Charles University, Viničná 7, 128 43 Praha 2, Czech Republic1. IntroductionIdentifying immigrants within various cultural contexts can help us to understand mobility and how people were able to retain their identity while integrating into new communities (the issue is summarised, for example, in overview books by Quast, 2009; Meller et al., 2017 or Ormrod et al., 2020; the problem was also addressed by Storti, 2020). It is not easy to document migration in the archaeological record, as material culture, being more a proof of social communication, cannot be a reliable source of information on the mobility of its bearers (Burmeister, 2017, pp.57–60; Reiter and Frei, 2019, p.1). Perhaps, some elements of the burial rite may give us a clue.1.1 Early medieval north-south oriented graves and views on their interpretationFrom the 9thcentury onwards, the predominant method of burial in Christian Central Europe was to place the deceased in the grave in an outstretched position on their back with the arms alongside the body and the head facing approximately west and the feet to the east. However, a certain percentage of graves difer from the prevailing burial rite. These include individuals buried in north-south or south-north orientations (with possible slight deviations to the west or east) and are often to be associated with abnormalities in the body position, e.g., acrouched or prone position. The reasons why some members of that society were treated diferently after death are still not very clear. Štefan (2009) analysed the phenomenon of non-standard (including unusually oriented) graves at burial sites inBohemia and Moravia of the 9th–12thcenturies, while Nezvalová (2016) summarised and statistically evaluated their occurrence in Moravia and south-western Slovakia in this period. The variations of the burial ritual in the Great Moravian and the post-Great Moravian environment from the territory of Slovakia and their evaluation have been dealt with by Hanuliak (1984; 1994; 2004a; 2004b). Their fndings show that there are rarely more than afew such cases per site and that they occur more often in the peripheral parts of burial grounds and the Volume XIV ● Issue 1/2023 ● 71–77*Corresponding author. E-mail: mfojtova@mzm.czARTICLE INFOArticle history:Received: 3rdJune 2022Accepted: 11thJanuary 2023DOI: words:Early Middle AgesSlavsStaré MěstoNa Valáchnon-standard grave orientationmobility analysis87Sr/86Sr ratioABSTRACTMigration has been used as one explanation for graves that deviate from the prevailing orientation and structure. Graves oriented in the north-south direction (i.e., deviating from the customary contemporary west-east orientation) at the Great Moravian and early medieval burial grounds of Přemyslid Bohemia and Moravia have attracted the attention of archaeologists for more than 100years. These are most often interpreted as the graves of foreigners, based on the assumption that diferent burial rites indicate immigrants, but this has not been confrmed or refuted with empirical evidence. With this study, we have taken the frst step towards testing the validity of this hypothesis. Samples from the dental enamel of the permanent molars of two individuals (H 16/2018 and H 18/2018) from the burial site “NaValách”, located at the Great Moravian central site in Staré Město, were subjected to stable strontium isotope analysis. This analysis can help to assess the likelihood of mobility for these individuals. From the results obtained, it is not possible to confrm the non-local origin of either of the individuals, although in the case of H 16/2018 we may theoretically consider it. However, to defnitively reject or confrm the hypothesis of a non-local origin of the people buried along the north-south azimuths, future analysis of a much larger sample size will be necessary.
image/svg+xmlIANSA 2023 ● XIV/1 ● 71–77Martina Fojtová, Zdeněk Vytlačil: Locals or Migrants? Strontium Isotope Analysis of Two North-South Oriented Great Moravian Graves72north-south orientation of the grave has no relation to the sex or age of the deceased. In contrast, during the early Middle Ages, the north-south orientation of graves was common in the burial sites of the Huns and Avars (Unger, 2006, p.32), or the Finno-Ugric population of Scandinavia (Niederle, 1911, p.360) and in present day northern Germany (Gerds and Wolf, 2015, vol.1, pp.51–57). However, for the Slavs in the territory of the Great Moravian Empire and Přemyslid Bohemia in the 9th–12thcentury, the north-south grave orientation is an atypical element. This is also refected in the approach of archaeologists to its interpretation.The idea that people of foreign origin or traditions are buried in north-south-oriented graves frst appeared in the work of L. Niederle (1911, p.359). This interpretation was then adopted by other researchers (e.g., Hrubý, 1955, p.77; Hochmanová-Vávrová, 1962, p.231; Eisner, 1966, p.382; Krumphanzlová, 1964, p.206; 1966, p.320; etc.). M.Hanuliak (2004a, p.112) adds that these may have been deceased people who were not sufciently integrated into the community, and ofers an alternative interpretation, according to which, through a range of north and south azimuths, the bereaved sought to prevent the unft deceased from travelling to the afterlife, which was intended primarily for upstanding members of society (Hanuliak, 2004b, p.46). The astronomer R. Rajchl (1987, p.173; 2006, p.426) approaches the problem from a completely diferent angle, suggesting that the placement of the deceased in the N-S direction could be related to the efort to place the dead in such a direction when the Sun is highest above the horizon during the day. Thus, it was not necessarily an efort to single out the deceased socially. Nevertheless, the link between non-local origin and diferent burial rites is also acknowledged by Croix et al.(2020) for the Viking-Age emporium or Jobling and Millard (2020) for medieval England.Hence, our main research question is: Do diferent burial rites (in this case, the north-south orientation of the grave) indicate immigrants, or were there other motivations for burying some people this way? It will, therefore, be necessary to focus directly on human remains. Bioarchaeological methods could help to address this research question by providing a diferent source of data about individual mobility (Price et al., 2002; Bentley, 2006; Montgomery, 2010; Slovak and Paytan 2011; etc.). Here we present strontium isotope data from the human teeth of two selected individuals in north-south oriented graves from Staré Město to investigate the possibility of their non-local origin. In recent years, similar research has been made at other sites and periods (Richards et al., 2008; Price et al., 2012; Slater et al., 2014; Krzewińska et al., 2018; Meijer et al., 2019; Vytlačil et al., 2021, etc.). The purpose of this paper cannot be – given the size of the sample tested – to confrm or refute this hypothesis, but the results obtained may suggest whether it has sense to pursue further in-depth research in the future.1.2 Mobility analysisStrontium isotopes in mobility analysis work on the principle of comparing the 87Sr content of the tissue from the analysed individual, expressed as the 87Sr/86Sr ratio, with the so-called locally bioavailable strontium. This term denotes the baseline strontium available in the area of interest that entered the local biosphere. The ratios vary geographically and this inter-regional variability of the 87Sr/86Sr ratios stems mainly from the bedrock as minerals difer in their 87Sr content, although various other sources such as water or air can play a role (Bentley, 2006; Budd et al., 2004; Price et al., 2002). As the rocks are eroded, strontium is released and, while it is not a biologically-active element, it can enter biological tissues as a substitute for calcium due to its chemical similarity (Bentley, 2006; Montgomery, 2010). As the 87Sr/86Sr ratio is carried throughout the food chain practically unchanged (Blum et al., 2000), the consumption of locally produced foodstufs by humans will therefore infuence their tissue 87Sr/86Sr correspondingly (Montgomery, 2010; Price et al., 2002). If an individual spent part of his life, typically early childhood, in a diferent and isotopically distinct environment, the measured 87Sr/86Sr will also difer.Various samples such as water, plants, or modern animals can be used for establishing a local isotopic baseline. Each has its advantages as well as drawbacks (see, for example, Maurer et al., 2012; Bataille et al., 2020; Holt et al., 2021). For this study, the tooth enamel of archaeological fauna has been used as reference material. Locally kept animals are generally expected to share the feeding range of humans and therefore display the 87Sr/86Sr ratio of the studied area (Price et al., 2002; Bentley, 2006). They also usually represent the most readily available sample material at previously excavated sites, are deposited in archaeological or museum collections, for example, and are not at risk of being infuenced by modern anthropogenic contaminants such as fertilisers (Bentley, 2006; Maurer et al., 2012), which need to be accounted for in such an agriculturally-exploited area as southern Moravia. However, this type of a sample faces the risk of displaying an inaccurate local 87Sr/86Sr ratio. Animals are often subject to trade or exchange, in which case they will not display local strontium values (Holt et al., 2021). Furthermore, the feeding area of animals might difer from humans (Maurer et al., 2012) or cover a notably greater range (Holt et al., 2021), thus leading to a shift in 87Sr/86Sr values. This risk can be mitigated to a certain degree by analysing a sufcient number of animals, preferably of such diferent species that would be expected to share the human feeding range, but it can never be excluded completely.The tissue of choice for bioarchaeological studies is tooth enamel, as it is often preserved in archaeological contexts and it has shown, unlike bone, greater resistance to diagenetic changes of its 87Sr/86Sr ratios (Budd et al., 2000; Hoppe et al., 2003; Trickett et al., 2003). The information in the enamel strontium, however, refects only early childhood – the time of the tooth crown formation; enamel does not undergo any further remodelling during a lifetime (Budd et al., 2004; Montgomery, 2010).
image/svg+xmlIANSA 2023 ● XIV/1 ● 71–77Martina Fojtová, Zdeněk Vytlačil: Locals or Migrants? Strontium Isotope Analysis of Two North-South Oriented Great Moravian Graves732. MaterialsThe locality “Na Valách” in Staré Město is among the most important burial sites of the early medieval Great Moravian Empire. More than 2000 graves and settlement features dating back mostly to the 9thand 10thcentury AD have been found there (Hrubý, 1955; Hochmanová-Vávrová, 1962; Galuška, 2002, 2004; Fojtová and Galuška, 2022; etc.). In 1949, the foundations of the frst church of proven Great Moravian age were discovered in the area (Hrubý, 1955). However, presently most of the site is built up and therefore it has not yet been explored in its entirety. During one of the most recent rescue excavations conducted in 2018, an area with 26 graves was uncovered on the north-western edge of the burial ground (49.0788817N, 17.4432139E; Figure 1). Most of the graves deviated in some way from the normal burial rite. Three graves (6/2018, 16/2018, and 18/2018) were oriented approximately in a north-south direction (Fojtová and Galuška, 2022).In grave number 16/2018, the skeleton of a female aged 40–60 years was lying in a supine position with her skull crushed at the right temple and with the mandible dislocated. Both upper limbs were bent at the elbows. The left forearm was positioned below the lumbar spine, and the right was lying on the chest with the hand pointing towards the chin. The position of the upper limbs and the mandible suggests that the body may have originally been wrapped in fabric or leather. The skeleton showed no signs of pathological changes except for a few dental caries and intravital tooth losses.Grave number 18/2018 contained the skeletal remains of a female aged 30–40 years in an extended supine position. The skull was lying on the occiput and leaning against the sloping wall of the grave-pit and the upper limbs were pointing slightly laterally. The deceased’s teeth were in very poor condition (numerous dental caries, intravital losses, and calculus). There were lesions of a “moth-eaten appearance” on the endocranial surface of the parietal bones. These were probably osteolytic metastases of some kind of carcinoma.Grave number 6/2018 was probably among the north-south oriented graves, but, unfortunately, this was fatally damaged by the digging of younger grave-pits. The fnd context was therefore unclear and, in addition, no teeth were preserved from the skeleton, so it could not be used for mobility analysis. The human dataset, therefore, includes the upper second right molar of the individual from the grave number 16/2018 and the upper frst left molar of the individual from the grave number 18/2018.The reference sample set consisted of tooth enamel samples from eight domestic pigs (Sus scrofa f. domestica), one dog (Canis lupus familiaris), and one Ovis/Capraspecimen. These came from skeletal remains found in graves both during current and past excavations of the “Na Valách” burial site.3. MethodsApproximately 20 mg of tooth enamel was sampled from the non-abrasive sides of the tooth as described