Stable oxygen and carbon isotope analysis and animal management systems in archaeology

1. Stable oxygen and carbon isotope analysis and animal management systems in archaeology Safoora Kamjan (GIA)

2. Outline • Introduction to stable oxygen and carbon analysis • Principles of isotopic analyses • Stable isotopes and their application in archaeology (Case studies) • Your questions

3. δ18O δ15N 87Sr/86Sr δ13C Images from: Schulting 1998; Wilmes 2014

4. Define research question * This is the most essential step! * Doing stable isotope analyses without having a clear question! * Has to be the other way! * Measuring isotope signals is ‘relatively’ straightforward but interpreting results is not.

5. Main questions • Herd mobility and trade • Animal diet/ seasonal changes in their diet • Birth season • Climate • Vegetation

6. What are stable oxygen and carbon?

7. Light-Stable isotopes

8. Isotopic baseline variation in the hydrological cycle by rainfall, evaporation, continentality, seasonality, altitude, temperature, relative humidity. Pederzani & Britton, 2019

9. Isoscapeof global patterns in δ18O in precipitation modelled from GNIP station data Pederzani & Britton, 2019

10. The oxygen isotopic composition of mammalian bone and tooth bioapatite Pederzani & Britton, 2019

11. Light-Stable isotopes

12. Stable carbon isotope can be used to detect animal diet and forest grazing CO2 recycling Low light -28‰ d13C plants -22‰ Enrichment = 5‰ d13C collagen -17‰ -23‰ Enrichment = 14.1‰ d13C enamel -13.9‰ -7.9‰

13. C3 versus C4 photosynthesis • C3 plants: δ13C -22 ‰ to -34 ‰C4 plants: δ13C -10 ‰ to -17 ‰ Different paths of photosynthesis

14. Suits et al. (2005) Global Biogeochem Cycle 19:GB1017

15. Basics of skeletal tissues • Bone (and dentine) • Composite material: organic + inorganic • Organic- mostly collagen proteins • Inorganic- mostly apatite minerals • Turnover/Regeneration • Bone is a dynamic ‘living’ tissue, its molecules are continuously replaced throughout life • Enamel (tooth crown) • Highly crystalized mineral (apatite + carbonate) with no significant protein component • No turnover/regeneration • Enamel is essentially an inert ‘dead’ tissue, it has no capacity to change once it is fully mineralized • Higher preservation in the archaeological remains

16. Series of δ18O measurements (black diamonds)of serial samples taken from the occlusalsurface (left) to the enamel root junction (ERJ; right) Photo from Pederzani& Britton, 2019

17. Measuring Isotopes • Purification • Isolation of material of interest from matrix • Mass Spectrometry • Most common method to measure isotope composition of sample • Delta Notation • Reporting stable isotope values relative to a given standard • Standards • International (external) and internal standards to assess accuracy and precision of measurements

18. Standards • These vary for different isotopes • Hydrogen:/Oxygen: VSMOW (Vienna Standard Mean Ocean Water) • Carbon: VPDB (Vienna Pee Dee Belemnite) • Nitrogen: AIR (Ambient Inhalable Reservoir) • Sulfur: VCDT (Vienna Canyon Diablo Troilite) • Chosen for their abundance & homogeneity • Allow comparisons of results across laboratories • Values for standards are set at zero by definition

19. From the site to the lab and your database!

20. Case study 1. Seaweed eating sheep • North Ronaldsaysheep. • the northernmost island of Orkney, off the north coast of Scotland https://www.youtube.com/watch?v=cxhN4Zmbrw4 Balasse et al. 2009

21. Balasse et al. 2009 • Historical reference to the prehistoric consumption of seaweed as fodder • Modern study= Tested by stable isotope analyses in tooth enamel bioapatite Two controlled population Results: No overlap between their d13C d13C of sheep relying of seaweed= -3.1‰ (very low amplitude of intra- tooth variation) d13C of grazing sheep= -17.7‰ and -15.1‰ • Archaeological faunal remains= winter consumption of seaweed in one sheep from the Neolithic site of Point of Cott and one sheep from the Iron Age assemblage of Mine Howe.

22. Seaweed-eating sheep Grazing sheep Balasse et al. 2009

23. Case study 2 • Seasonal mobility of hunter-gatherers and mouflon (Ovisorientalis) in the Kalavan 1, a seasonal hunting campsite in NE Armenia. • The site lies at an elevation of 1640 m • Searching for obsidian in high altitude sources from the spring to the summer and settling at Kalavan 1 at the end of summer/autumn to coincide with the migration of wild herds. δ13C Summer Winter δ18O Summer Winter Tornero et al. 2016

24. The reverse pattern of stable oxygen and carbon ratio= possibly as a result of vertical transhumance Tornero et al. 2016

25. Case study 3.Cattle milk and meat production at Neolithic Bercy, France Cattle slaughtering patter= Post-lactation model ? Gillis et al. 2017

26. Hypothetical slaughter curve for cattle Post-lactation slaughter (Peske 1994). Slaughter of calves before 6 months - production could have beenmaintained by artificial means or the sharing of calves between several females (Roffetet al. 2017)

27. Ethnographic observations and modern references In the lack of calves: Association of fake calf in southern Sudan (http://southersudan.prm.ox.ac.ul/details/1998.355.353.2/). Insufflation technique practice- illustrated by Kolb (1719: 468) from Hettentons of the Cape

28. Stable oxygen and carbon analyses=1. birth seasonality2. diet

29. Estimating birth season based on d18O expected Measured schematic diagram of the seasonal cycle of δ18O (Tower et al. 2017)

30. Cattle birthing season in Bercy • Cattle in Bercy were born over a period spanning around six months.

31. Cattle grazing environment in Bercy • Contribution of leafy fodder in Cattle diet during winter evident based on low 13C. Grazing in C3 environment Contribution of 13C depleted plants from dense forest Balasse et al. 2012

32. THANK YOU FOR YOUR ATTENTION

33. Your questions: …. focus more on nutritional stress & disease instead of diet reconstruction? Laurie J. Reitsema, 2013. Beyond diet reconstruction: stable isotope applications to human physiology, health, and nutrition.

34. Is there any difference in health between cows that eat C3 plants and C4 plants?Why are C4 plants introduced to the steers after weaning?

35. Since the sampling procedures are yet to be improved, what would be a possible way to do so? • 1. high possibility of contamination • 2. time consuming • 3. expensive • 4. …

36. *In the article by Balasse they say a lag in enamel formation may come from a switch in diet, how could we know this for certain and not that this occurred because of another physiological factor?* Why would a lagging enamel mineralization process lead to an under-estimation of the isotopic composition?*Could the lag in enamel mineralization differ significantly in animals of specific species?* Is there any knowledge about enamel mineralization in species other than Bostaurus?

37. Are there isotope/molecular traits that are visible on bones before/without analysis? (Like, would it be possible a certain diet makes bone structure look different?) DP: How would you draw conclusions if isotope evidence is not visible in the archaeological record?

38. Are there already internationally recognized guidelines regarding the handling (collecting, sampling and analysing) of isotope data within archaeology?* Kohn et al. 1998. Variability in oxygen isotope compositions of herbivore teeth: reflections of seasonality or developmental physiology?

39. *Besides the iconographic evidence for milking have any remains of the possible milking vessels been found or ceramics with a form of residue?*Would it be possible to give a clear answer weather people drank milk back than, or will this always be speculation? Cynthianne Debono Spiteri, et al. 2016. Regional asynchronicity in dairy production and processing in early farming communities of the northern Mediterranean,”. ProcNatl AcadSci USA (113:13594–13599; first published November 14, 2016; 10.1073/pnas.1607810113). Itan Y, Powell A, Beaumont MA, Burger J, Thomas MG (2009) The Origins of Lactase Persistence in Europe. PLoSComputBiol 5(8): e1000491. doi:10.1371/journal.pcbi.1000491 ‘cheese-strainers’ vesels from LBK culture (Salque et al. 2013)

40. Are there examples of the use of insufflation in the north-west european prehistory? • Why could you possibly want to blow up a cow's uterus? • Can this technique be archaeologically seen anywhere else in the world? • …as we do not know the exact socio-cultural context of these rock paintings, would Stable Isotope Analysis then not be a more reliable technique to better understand the presence of milking within these societies?

41. The paintings include human figures drinking direct from the cow's udders. Was it common to preserve the milk for later use and if so how did they accomplish that?

42. At the "Sahara case" the rock art is the basic form of documentation. Generally speaking, how reliable do you think the rock iconography is for this period of time, given that we do not always have many available sources.