“Diet Reconstruction of a Neolithic Population from Hypogea Burials of Vale de Barrancas 1 Using Bone Collagen Stable Isotopic Signature

Barrocas Dias, C.

Maurer, A.-F.

Nunes, T.

Soberl, L.

Valera, A. C.

Portuguese

Repositório Científico da Universidade de Évora

Vale de Barrancas 1. A necrópole neolítica.   85     5 DIET RECONSTRUCTION OF A NEOLITHIC POPULATION FROM HYPOGEA BURIALS OF VALE DE BARRANCAS 1 USING BONE COLLAGEN STABLE ISOTOPIC SIGNATURES   Lucija Soberl Anne-France Maurer António Carlos Valera Tiago Nunes Cristina Barrocas Dias     5.1 - INTRODUCTION  The archaeological site of Vale de Barrancas 1, situated in the Alentejo region, South Portugal, was discovered in the context of the construction of a motorway and excavated by Era Arqueologia between 2011 and 2012. An abundance of negative structures was discovered, dated to the Bronze Age and Late Roman period, alongside nine underground rock-cut tombs (hypogea) dated to the late Middle Neolithic (see Chapters 2 and 3).  Paleoanthropological analysis of the large quantities of manly disarticulated human bones recovered from these funerary structures has provided basic information on the buried populations with a minimum number of individuals estimated of 57 (see Chapter 4).  Given the relatively well preservation of the human bones, a study was conducted to reconstruct the diets and subsistence strategies of this population using isotopic signatures, comparing it with available isotopic information of humans and animals from the Neolithic period in the region of Alentejo hinterland. Era Monográfica 4 (2020)  86   Stable isotope analysis is an established technique used for reconstruction of past human diets by measuring ratios of stable carbon (13C/12C = δ13C), nitrogen (15N/14N = δ15N) and sulphur (34S/32S = δ34S) isotopes preserved in the organic component of bones and extracted as collagen. These bulk isotopic results enable differentiation between trophic levels within terrestrial and marine food chains and dietary input plants with different photosynthetic pathways (C3 vs. C4). Multi-isotopic analysis also provides additional information on subsistence strategies in cases where studies are limited by poor preservation or the lack of archaeozoological and archaeobotanical remains.  5.2 – METHODOLOGY AND SAMPLES   Seven hypogea were sampled (H1, H2. H3. H4, H5, H7 and H8), selecting right tibias from excavated osteological remains to reliably distinguish between individuals. Most of the bones come from ossuary deposits, with a minority coming from anatomical connections and dispersed deposits (Table 5.1).  Prior to the removal of approximately 1-2 g of bone, its surface was cleaned with a diamond drill bit, in other to remove any modern contaminants and soil. Collagen was extracted using a modified Longin method (Login, 1971), which includes bone demineralization in 0.5 M HCI, followed by removal of fulvic and humic acids with 0.125 M NaOH and gelatinization in 0.01 M HCI.  Lyophilized collagen was then analysed using EA-IRMS to obtain elemental composition (C%, N%) of the samples, as well as the δ13C and δ15N isotopic ratios.  5.3 – RESULTS AND CONTEXTUALIZATION   Collagen was successfully extracted from 54% of the bone samples from Vale Barrancas 1, with an average collagen yield of 1.21% (van Klinken, 1999) (Table 5.1).   Table 5.1 – Samples and δ13C and δ15N isotopic ratios from Vale de Barrancas 1.   Lab N. Structure Est. Unit Bone N. Sample type Context Collagen yeld % %N %C C:N δ15N ‰ δ13C ‰VdB 01 4510 653 Right Tibia Ossuary 0.59VdB 02 4510 4 Right Tibia Ossuary 0.91VdB 03 4510 6 Right Tibia Ossuary 0.71VdB 04 4510 7 Right Tibia Ossuary 1.19 14,7 42,8 3.39 9,8 -18,9VdB 05 7215 28 Right Tibia Ossuary 1.12 14,6 41,7 3.34 10,1 -19,8VdB 06 7215 199 Right Tibia Ossuary 0.49VdB 07 7215 77 Right Tibia Ossuary 2.19 14,5 41,2 3.32 10,1 -18,9VdB 08 7215 116 Right Tibia Ossuary 0.66VdB 09 6328 3 Right Tibia Connection 1.36 14,1 40,9 3.39 8,3 -19,3VdB 10 6325 73 Right Tibia Connection 0.40VdB 11 6329 2 Right Tibia Connection 1.20VdB 12 6333 7 Right Tibia Connection 3.52 15,0 42,6 3.31 9,1 -18,3VdB 13 6135 9 Right Tibia Ossuary 0.95 14,5 42,5 3.41 9,0 -18,8VdB 14 6137 4 Right Tibia Connection 0.78 14,0 40,9 3.40 9,5 -19,5VdB 15 8304 75 Right Tibia Dispersed 0.56VdB 16 8304 76 Right Tibia Dispersed 1.12 13,5 38,3 3,31 9,2 -19,9VdB 17 8305 7 Right Tibia Connection 0.93 12,9 37,2 3.36 9,0 -19,2VdB 18 11209 2 Right Tibia Ossuary 0.50VdB 19 11211 1 Right Tibia Connection 0.49VdB 20 11210 8 Right Tibia Connection 3.17 14,7 41,4 3.29 9,5 -19,4VdB 21 11507 151 Right Tibia Ossuary 2.32 14,6 40,6 3.25 9,1 -18,1VdB 22 11507 55 Right Tibia Ossuary 2.16 14,6 41,0 3.28 9,6 -18,6VdB 23 11507 192 Right Tibia Ossuary 1.20 13,0 37,1 3.32 9,8 -19,2VdB 24 11507 3 Right Tibia Ossuary 0.42Average 1.21 14,2 40,6 9,4 -19,18H1H2H3457Vale de Barrancas 1. A necrópole neolítica.   87    Table 5.2 – δ13C and δ15N isotopic ratios for human and animals from other Neolithic contexts of Alentejo region.                     Figure 5.1 – Plot of δ13C and δ15N isotopic ratios for human and animals from Neolithic contexts of Alentejo region. Site %N %C δ15N % δ13C % C:N Bib. Ref. Amostra %N %C δ15N % δ13C % C:N Bib. Ref.? ? 8,98 -19,64 3,27 Carvalho, 2013 Bos taurus 14,4 40,4 6,9 -20,6 3,3 Zalaite et al. , 2018? ? 9,43 -19,45 3,33** Carvalho, 2013 Bos taurus 14,1 41,5 6,2 -20,2 3,4 Zalaite et al ., 2018? ? 9,39 -19,1 3,36 Carvalho, 2013 Bos taurus 13,9 41,2 5,8 -20,5 3,5 Zalaite et al. , 2018? ? 8,78 -19,46 3,35* Carvalho, 2013 Bos primigenius 13,6 40,2 6,4 -20,1 3,4 Zalaite et al ., 2018? ? 10,26 -20,15 3,63* Emslie et al. , 2015 Bos primigenius 14,3 42,1 6,6 -20,3 3,4 Zalaite et al. , 2018? ? 10,13 -20,58 3,34** Emslie et al.,  2015 Equus caballus 13,1 39,4 5,6 -20,8 3,5 Zalaite et al. , 2018? ? 10,1 -19,38 3,32 Carvalho, Rocha, 2015 Equus caballus 13,9 40,7 4,2 -20,5 3,4 Zalaite et al ., 2018? ? 10,06 -19,11 ? Carvalho, Rocha, 2015 Cervus elaphus 12,9 38,6 5,8 -20,5 3,5 Zalaite et al. , 2018? ? 10,89 -19,42 3,59 Carvalho, Rocha, 2015 Cervus elaphus 14,1 41,7 7,7 -19,0 3,4 Zalaite et al ., 2018Cervus elaphus 14.2 40.2 5,3 -20,3 3,4 Zalaite et al. , 2018Ovis/Capra 14,9 41,7 4,8 -20,1 3,3 Zalaite et al ., 2018Ovis/Capra 14,3 41,7 5,1 -19,9 3,4 Zalaite et al. , 2018Ovis/Capra 14,4 42,1 3,3 -19,9 3,4 Zalaite et al ., 2018Ovis/Capra 14,2 41,8 5,7 -20,8 3,4 Zalaite et al. , 2018Sus sp. 13,5 40,1 5,6 -19,4 3,5 Zalaite et al ., 2018Sus sp. 14,5 42,6 6,3 -19,8 3,4 Zalaite et al. , 2018Sus sp. 14,2 41,7 4,7 -20,0 3,4 Zalaite et al ., 2018Sus sp. 12,3 42,7 5,5 -21,1 4,1 Zalaite et al. , 2018Canis familiaris 12,1 33,4 9,8 -19,3 3,2 Zalaite et al ., 2018Sobreira de CimaIsotopic values for Neolithic humans Isotopic values for animals of the Neolithic phase of PerdigõesAnta da Cabeceira 4** Valores para um mesmo indivíduo* Valores para um mesmo indivíduoEra Monográfica 4 (2020)  88  Typically, the collagen quality and presence of contaminants can be assessed with the C:N ratio falling between 2.9 and 3.6 (DeNiro, 1985). The range of C:N ratios calculated for the Vale Barrancas 1 samples was between 3.2 and 3.4 ±0.05. The low collagen yield values suggest a high degree of degradation, most likely as the result of diagenetic post-depositional processes and depositional age.  Most of the δ13C and δ15N isotopic values for the analysed human remains are clustered closely together, suggesting a uniform population without any evident differentiation based on dietary preferences (Figure 5.1). Bulk isotopic ratios of carbon and nitrogen suggest that C3 plants were the dietary basis of the analysed individuals, complemented with protein deriving from terrestrial herbivores and eventually their secondary products.  Comparison with other available isotopic data from other Neolithic burials of the region, such as the hypogea necropolis of Sobreira de Cima (Carvalho, 2013; Emslie et al., 2015) and the megalithic monument of Anta da Cabeceira 4 (Carvalho, Rocha, 2015), displays very similar dietary patterns. When the available isotopic ratios for humans are compared with the isotopic data of the Neolithic fauna for Perdigões ditched enclosures (Zalaite et al., 2018), it shows that δ15N is in average 3,50/00 higher in humans, suggesting the preserved trophic level effect of 2-40/00, as reported in the literature, while the trophic level increments for δ13C ratios are smaller (approximately of 10/00). The exceptions are the isotopic ratios of one dog, that plots right in the middle of the humans, indicating the proximity and integration of dogs in human communities, probably fed with remains of human food.  5.4 - CONCLUSIONS   The number of sites with available δ13C and δ15N isotopic ratios for the Neolithic in Alentejo hinterland is still scarce. Nevertheless, the present data draws a coherent and homogeneous picture, indicating a general dietary mixed pattern, with an important contribution of C3 plants complemented by proteins obtained from herbivores animals and their secondary products. This, though, does not clarify the balance between produced subsistence items and gathered ones.  In fact, the study of the Neolithic sequence of Perdigões (Valera, 2018), covering the end of the Middle Neolithic and the Late Neolithic, showed the presence of cereals at the site in these phases, but with few empirical evidence (a seed and some pollen of cereals and legumes in the bottom of ditches). In the Late Neolithic phase of Moinho de Valadares 1 the indirect presence of barley was established (Queiroz, Ruas, 2013). But these records are sparse, and the indirect evidence of agriculture is also limited for the great majority of settlements of the period in the region (Valera, 2018). So, it is hard to value the contribution of agriculture vs. gathering, but the isotopic data indicates that agriculture is already central in the subsistence strategies of these communities. The same problem exists regarding the protein contribution. At Perdigões, the faunal record for the end of the Middle Neolithic, which is coincident with the chronological span of Vale Barrancas 1 necropolis, shows an equivalence of wild and domestic species, and only in the Late Neolithic the domestic animals clearly overcome the hunted ones (Almeida, Valera, in press), indicating that hunting still was an important source of protein during the late Middle Neolithic. What the current data suggests, for the subsistence strategies of these population of Alentejo hinterland at the end of the Middle Neolithic, is a clear terrestrial dietary pattern based on the production of C3 plants and animal husbandry, but where the contribution of gathering and hunting is still quite relevant. This relevance of gathering and hunting would decay during the Late Neolithic and Chalcolithic in favour of agriculture and pastoralism. By the late 3rd millennium BC, thought, hunting seems to grow again at a cost of pastoralism (Almeida, Valera, in press), which can be interpreted as another symptom of the crises of the end of the millennium.    Vale de Barrancas 1. A necrópole neolítica.   89  BIBLIOGRAPHIC REFERENCES ALMEIDA, VALERA, in press Almeida, N.; Valera, A.C. (in press) – Animal consumption and social change: the vertebrates from Ditch 7 in the context of a diachronic approach to the faunal remains at Perdigões enclosure (3400-2000 BC), Archaeofauna, Madrid. Universidad Autonoma de Madrid. CARVALHO, 2013 Carvalho, A.F. (2013) – Análise de isótopos estáveis de quatro indivíduos do Sepulcro 1 da Necrópole de hipogeus da Sobreira de Cima (Vidigueira, Beja): primeiros resultados paleodietéticos para o Neolítico do Interior Alentejano. In: A.C. Valera (Coord.), Sobreira de Cima. Necrópole de Hipogeus do Neolítico (Vidigueira, Beja), Era Monográfica, 1, Lisboa, NIA-ERA, 109-112. CARVALHO, ROCHA, 2015 Carvalho, A.F.; Rocha, L. (2015) – Datação directa e análise de paleodietas dos indivíduos da anta de Cabeceira 4: contribuição para o estudo das origens do megalitismo do Centro-Sul de Portugal. Poster apresentado ao XI Congresso Internacional de Arqueometria, Évora (2015). DeNIRO, 1985 DeNiro, M.J. (1985) – Postmortem preservation and alteration of in vivo bone collagen isotope ratios in relation to palaeodietary reconstruction, Nature 317: 806–809. doi.org/10.1038/317806a0. EMSLIE et al., 2015 Emslie, S.D.; Brasso, R.; Patterson, W.P.; Valera, A.C.; McKenzie, A.; Silva, AM.; Gleason, J.D.; Blum, J.D. (2015) – Chronic mercury exposure in Late Neolithic/Chalcolithic populations in Portugal from the cultural use of cinnabar, Scientific Reports, (1/10/2015). DOI: 10.1038/srep14679. LONGIN, 1971 Longin R. (1971) – New method of collagen extraction for radiocarbon dating, Nature, 230 (5291): 241-242. doi.org/10.1038/230241a0 QUEIROZ, RUAS 2013 Queiroz, P. F.; Ruas, J.P (2013) – Dados sobre elementos vegetais no povoado do Moinho de Valadares I, In: A.C. Valera (Ed.), As comunidades agropastoris na margem esquerda do Guadiana. 2ª medate do IV aos inícios do II milénio AC. Memórias d’Odiana, 2ª Série, 6: 378-380. VALERA, 2018 Valera, A.C. (2018) – Os Perdigões Neolíticos. Génese e desenvolvimento (De meados do 4º aos inícios do 3º milénio AC), Era Monográfica, 1, Lisboa, NIA-ERA. Van KLINKEN, 1999 van Klinken, G.J., (1999) – Bone collagen quality indicators for palaeodietary and radiocarbon easurements, Journal of Archaeolog. Science, 26: 687–695. http://dx.doi.org/10.1006/jasc.1998.0385. ZALAITE et al., 2018 Zalaite, I.; Maurer, A.F. ; Grimes, V. ; Silva, A.M. ; Ribeiro, S.; Santos J.F.; Dias, C.B.; Valera, A.C. (2018) – Diet and mobility of fauna from Late Neolithic–Chalcolithic site of Perdigões, Portugal. Journal of Archaeological Science: Reports, 19, p.674–685. doi.org/10.1016/j.jasrep.2018.03.033        

Diet Reconstruction of a Neolithic Population from Hypogea Burials of Vale de Barrancas 1 Using Bone Collagen Stable Isotopic Signatures

http://dspace.uevora.pt/rdpc/bitstream/10174/34350/1/Vale_de_Barrancas_1_A_necropole_de_hipog-85-89.pdf

Diet Reconstruction of a Neolithic Population from Hypogea Burials of Vale de Barrancas 1 Using Bone Collagen Stable Isotopic Signatures

Abstract

Similar works

Full text

Available Versions

Repositório Científico da Universidade de Évora