Rhiannon Stevens | University College London (original) (raw)
Papers by Rhiannon Stevens
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Chemical Geology, 2013
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Oxford Journal of Archaeology, 2013
ABSTRACT The formal Iron Age cemetery at Suddern Farm, located near Danebury hillfort, provides a... more ABSTRACT The formal Iron Age cemetery at Suddern Farm, located near Danebury hillfort, provides a unique opportunity to investigate whether differences in burial tradition and ritual behaviour seen at the two sites are linked to access to food resources during life. We measured the carbon and nitrogen isotopic ratios of 40 humans from Suddern Farm and compared this information to previously published faunal data from the site and human isotopic data from Danebury. Despite substantial variation in the faunal isotope signatures, the adult humans have notably homogeneous isotopic results, which are very similar to those at Danebury. This indicates that they had similar access to dietary resources, and supports other evidence for the interdependence of sites with regard to their farming practices. Any social practices that define groups within Hampshire Iron Age society at these sites do not seem to have had any detectable influence on diet.
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Journal of Archaeological Science, 2013
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Chemical Geology, 2013
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The seasonal pattern of shellfish foraging at the archaeological site of Haua Fteah in the Gebel ... more The seasonal pattern of shellfish foraging at the archaeological site of Haua Fteah in the Gebel Akhdar, Libya was investigated from the Epipaleolithic to the Neolithic via oxygen isotope (d18O) analyses of the topshell Phorcus (Osilinus) turbinatus. To validate this species as faithful year-round palaeoenvironmental recorder, the intra-annual variability of d18O in modern shells and sea water was analysed and compared with measured sea surface temperature (SST). The shells were found to be good candidates for seasonal shellfish forging studies as they preserve nearly the complete annual SST cycle in their shell d18O with minimal slowing or stoppage of growth. During the terminal Pleistocene Early Epipaleolithic (locally known as the Oranian, with modeled dates of 17.2e12.5 ka at 2s probability, Douka et al., 2014), analysis of archaeological specimens indicates that shellfish were foraged year-round. This complements other evidence from the archaeological record that shows that the cave was more intensively occupied in this period than before or afterwards. This finding is significant as the period of the Oranian was the coldest and driest phase of the last glacial cycle in the Gebel Akhdar, adding weight to the theory that the Gebel Akhdar may have served as a refugium for humans in North Africa during times of global climatic ex- tremes. Mollusc exploitation in the Latest Pleistocene and Early Holocene, during the Late Epipaleolithic (locally known as the Capsian, c. 12.7 to 9 ka) and the Neolithic (c. 8.5 to 5.4 ka), occurred predominantly during winter. Other evidence from these archaeological phases shows that hunting activities occurred during the warmer months. Therefore, the timing of Holocene shellfish exploitation in the Gebel Akhdar may have been influenced by the seasonal availability of other resources at these times and possibly shellfish were used as a dietary supplement when other foods were less abundant.
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Palaeogeography, …, Jan 1, 2008
Pleistocene faunal δ 15N variations are thought to reflect changes in climatic and environmental ... more Pleistocene faunal δ 15N variations are thought to reflect changes in climatic and environmental conditions. Researchers are still unclear, however, which climatic/environmental parameter is the primary control on Pleistocene faunal δ 15N values. Through extensive nitrogen isotope analysis of Late Pleistocene reindeer (Rangifer tarandus) collagen we investigated whether permafrost development during the Late Pleistocene coincided with changes in δ 15N values. After 45 ka BP reindeer δ 15N declined, with lowest δ 15N values observed after the Last Glacial Maximum (LGM), between 15 and 11 ka BP. The decline in δ 15N appears to be of a greater magnitude in more northern regions than in the South of France, a pattern similar to that previously observed for horse. On a global scale, ecosystem δ 15N is controlled by the relative openness of the nitrogen cycle, which in turn is controlled by climate. Low soil and plant δ 15N are observed in cold and/or wet regions and high δ 15N are seen in hot and/or arid areas. The regional pattern in reindeer δ 15N decline mimics the pattern of climatic deterioration in Europe culminating at the LGM, with climate cooling being more intense in northern Europe than in southern Europe. However, the lowest reindeer δ 15N values are observed after temperatures started to rise. This may have been due to a lag in the response of the nitrogen cycle to increasing temperatures. Alternatively it may have been linked to the influence of permafrost degradation on soil and plant δ 15N and thus faunal δ 15N. The renewed climatic cooling during the Younger Dryas did not see a fall in reindeer δ 15N. Limited data does, however, suggest a post Younger Dryas depletion in reindeer δ 15N values.
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"Middens of the southern British late Bronze and Iron Age are vast accumulations of cultural debr... more "Middens of the southern British late Bronze and Iron Age are vast accumulations of cultural debris
that can be explained as refuse dumps linked with large periodic feasting events. A distinctive
feature of these sites is that their faunal assemblages invariably comprise a considerably higher
proportion of pig remains than contemporaneous settlement sites. This paper presents results
from a programme of stable carbon (d13C) and nitrogen (d15N) isotope analysis of fauna from two
major midden sites, Llanmaes in South Wales and Potterne in Wiltshire. The research aim is to
reconstruct husbandry strategies and foddering regimes, particularly concerning pigs, to better
understand how the challenges of raising large herds were met. Analysis produced exceptionally
wide-ranging results for pigs and other domesticates at both sites, particularly in terms of d15N
values, demonstrating that diverse foddering strategies were employed. Diversity in the late
Bronze Age pig foddering regimes indicates that the Neolithic husbandry practices (focusing on
woodland fodder) had not been abandoned, but that new husbandry methods (consumption of
household waste) were also being practised, which subsequently became more widely
established in the Iron Age. The heterogeneity of signatures suggests that animals may have
been husbanded in a piecemeal fashion at a local, household level. This in turn hints that fauna
may have been brought to these sites from households across the surrounding landscape, rather
than being husbanded by specialist producers in the vicinity of the middens."
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Journal of the North …, 2009
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The carbon isotopic characterisation of ruminant lipids associated with ceramic vessels has been ... more The carbon isotopic characterisation of ruminant lipids associated with ceramic vessels has been crucial for elucidating the origins and changing nature of pastoral economies. δ(13)C values of fatty acids extracted from potsherds are commonly compared with those from the dairy and carcass fats of modern domesticated animals to determine vessel use. However, the processing of wild ruminant products in pottery, such as deer, is rarely considered despite the presence of several different species on many prehistoric sites. To address this issue, the carbon isotope range of fatty acids from a number of red deer (Cervus elaphus) tissues, a species commonly encountered in the European archaeological record, was investigated. Lipids were extracted from 10 modern red deer tissues obtained from the Slowinski National Park (Poland). Fatty acids were fractionated, methylated and analysed by gas chromatography/combustion/isotope ratio mass spectrometry (GCCIRMS). The δ(13)C values of n-octadecanoic acid and n-hexadecanoic acid, and the difference between these values (Δ(13)C), were compared with those from previously published ruminant fats. Nine of the ten deer carcass fats measured have Δ(13)C values of less than -3.3‰, the threshold previously used for classifying dairy products. Despite considerable overlap, dairy fats from domesticated ruminants with Δ(13)C values less than -4.3‰ are still distinguishable. The finding has implications for evaluating pottery use and early pastoralism. The processing of deer tissues and our revised criteria should be considered, especially where there is other archaeological evidence for their consumption.
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Journal of Archaeological Science, 2009
Trou de Chaleux and Goyet are caves situated less than 30km apart in Belgium that contain stratif... more Trou de Chaleux and Goyet are caves situated less than 30km apart in Belgium that contain stratified Magdalenian artefacts and butchered faunal remains. Published radiocarbon dates suggest that both sites were contemporaneously occupied during to the Late-glacial interstadial. It has previously been suggested that the Trou de Chaleux Late-glacial faunal remains might be slightly older than those at Goyet Cave,
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Palaeogeography, …, Jan 1, 2012
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Through isotopic investigations of directly dated human remains recovered from the Eton College R... more Through isotopic investigations of directly dated human remains recovered from the Eton College Rowing Course we examine changes in diet from the Neolithic to the Roman period. The human isotope signatures point to a diet based on C3 terrestrial resources. A significant correlation is visible between human δ13C values and time, but no such trend is observed in δ15N. The animal isotope data from Eton are unevenly distributed making it difficult to determine if the human values mirror the animal values. To assess whether the results from Eton are typical we compare our results to isotope data from other British sites dating from the Neolithic to the Roman period. Across this time period we see a strong correlation between the mean δ15N of the humans and that of the main domesticated herbivores, with an offset of ~4.5‰ between the two. Thus the changes in the human isotope values are likely linked to changes in the isotopic signatures of the herbivores rather than changes in the protein composition of human diets. By contrast no clear temporal relationship is observed between the mean δ13C of the humans and that of the main domesticated herbivores, with an offset of ~1.4‰ between the two. There is however a weak correlation observed between the mean δ13C of the humans and that of the cattle, which may account for some of the variation in human δ13C values between sites. The absence of a strong correlation between mean human and animal δ13C suggests that the primary factor influencing human δ13C values between sites is dietary composition. The lack of co-variation between δ13C and δ15N is likely to reflect the different representation of dietary macronutrients. Given that the nitrogen results suggest that the animal protein consumption patterns are similar across sites, the human δ13C variation between sites is likely to reflect the plant portion of the diet.
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Quaternary …, Jan 1, 2011
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…, Jan 1, 2011
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Palaeodietary studies typically focus on the analysis of bone collagen due to the limited availab... more Palaeodietary studies typically focus on the analysis of bone collagen due to the limited availability of plant remains. Isotopic analysis of plant remains, however, allow for a more extensive consideration of the contribution of plants to the human diet and can potentially provide information about the environment in which the crops were grown. This paper reports the results of carbon and nitrogen isotope analyses performed on charred barley and wheat grains recovered from pits within Danebury Iron Age hillfort. To the best of our knowledge, this is the first Iron Age site in Britain from which charred grains have been isotopically analysed. Our results suggest that cereals found at the hillfort were grown in several different environmental contexts. The isotope data demonstrate that the herbivores were not consuming a diet primarily based on grains as the d15N values of the grains are very similar to those of the herbivores. Palaeodietary investigations typically assume that humans eating plant protein only would have the same d15N value as the local herbivores. This assumption is clearly invalid at Danebury, where the humans and animals appear to have consumed either different parts of the same plants or different plants. Researchers typically interpret high differences between human and animal d15N values as indicative of diets high in animal protein, however where major plant resources have d15N values similar to those of the herbivores our ability to distinguish between plant and animal sources of protein in the diet is limited. Our research has demonstrated that whenever possible it is desirable to measure the isotopic signatures of potential major plant resources in order to understand past subsistence strategies.
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Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Chemical Geology, 2013
Bookmarks Related papers MentionsView impact
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Oxford Journal of Archaeology, 2013
ABSTRACT The formal Iron Age cemetery at Suddern Farm, located near Danebury hillfort, provides a... more ABSTRACT The formal Iron Age cemetery at Suddern Farm, located near Danebury hillfort, provides a unique opportunity to investigate whether differences in burial tradition and ritual behaviour seen at the two sites are linked to access to food resources during life. We measured the carbon and nitrogen isotopic ratios of 40 humans from Suddern Farm and compared this information to previously published faunal data from the site and human isotopic data from Danebury. Despite substantial variation in the faunal isotope signatures, the adult humans have notably homogeneous isotopic results, which are very similar to those at Danebury. This indicates that they had similar access to dietary resources, and supports other evidence for the interdependence of sites with regard to their farming practices. Any social practices that define groups within Hampshire Iron Age society at these sites do not seem to have had any detectable influence on diet.
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Journal of Archaeological Science, 2013
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Chemical Geology, 2013
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The seasonal pattern of shellfish foraging at the archaeological site of Haua Fteah in the Gebel ... more The seasonal pattern of shellfish foraging at the archaeological site of Haua Fteah in the Gebel Akhdar, Libya was investigated from the Epipaleolithic to the Neolithic via oxygen isotope (d18O) analyses of the topshell Phorcus (Osilinus) turbinatus. To validate this species as faithful year-round palaeoenvironmental recorder, the intra-annual variability of d18O in modern shells and sea water was analysed and compared with measured sea surface temperature (SST). The shells were found to be good candidates for seasonal shellfish forging studies as they preserve nearly the complete annual SST cycle in their shell d18O with minimal slowing or stoppage of growth. During the terminal Pleistocene Early Epipaleolithic (locally known as the Oranian, with modeled dates of 17.2e12.5 ka at 2s probability, Douka et al., 2014), analysis of archaeological specimens indicates that shellfish were foraged year-round. This complements other evidence from the archaeological record that shows that the cave was more intensively occupied in this period than before or afterwards. This finding is significant as the period of the Oranian was the coldest and driest phase of the last glacial cycle in the Gebel Akhdar, adding weight to the theory that the Gebel Akhdar may have served as a refugium for humans in North Africa during times of global climatic ex- tremes. Mollusc exploitation in the Latest Pleistocene and Early Holocene, during the Late Epipaleolithic (locally known as the Capsian, c. 12.7 to 9 ka) and the Neolithic (c. 8.5 to 5.4 ka), occurred predominantly during winter. Other evidence from these archaeological phases shows that hunting activities occurred during the warmer months. Therefore, the timing of Holocene shellfish exploitation in the Gebel Akhdar may have been influenced by the seasonal availability of other resources at these times and possibly shellfish were used as a dietary supplement when other foods were less abundant.
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Palaeogeography, …, Jan 1, 2008
Pleistocene faunal δ 15N variations are thought to reflect changes in climatic and environmental ... more Pleistocene faunal δ 15N variations are thought to reflect changes in climatic and environmental conditions. Researchers are still unclear, however, which climatic/environmental parameter is the primary control on Pleistocene faunal δ 15N values. Through extensive nitrogen isotope analysis of Late Pleistocene reindeer (Rangifer tarandus) collagen we investigated whether permafrost development during the Late Pleistocene coincided with changes in δ 15N values. After 45 ka BP reindeer δ 15N declined, with lowest δ 15N values observed after the Last Glacial Maximum (LGM), between 15 and 11 ka BP. The decline in δ 15N appears to be of a greater magnitude in more northern regions than in the South of France, a pattern similar to that previously observed for horse. On a global scale, ecosystem δ 15N is controlled by the relative openness of the nitrogen cycle, which in turn is controlled by climate. Low soil and plant δ 15N are observed in cold and/or wet regions and high δ 15N are seen in hot and/or arid areas. The regional pattern in reindeer δ 15N decline mimics the pattern of climatic deterioration in Europe culminating at the LGM, with climate cooling being more intense in northern Europe than in southern Europe. However, the lowest reindeer δ 15N values are observed after temperatures started to rise. This may have been due to a lag in the response of the nitrogen cycle to increasing temperatures. Alternatively it may have been linked to the influence of permafrost degradation on soil and plant δ 15N and thus faunal δ 15N. The renewed climatic cooling during the Younger Dryas did not see a fall in reindeer δ 15N. Limited data does, however, suggest a post Younger Dryas depletion in reindeer δ 15N values.
Bookmarks Related papers MentionsView impact
"Middens of the southern British late Bronze and Iron Age are vast accumulations of cultural debr... more "Middens of the southern British late Bronze and Iron Age are vast accumulations of cultural debris
that can be explained as refuse dumps linked with large periodic feasting events. A distinctive
feature of these sites is that their faunal assemblages invariably comprise a considerably higher
proportion of pig remains than contemporaneous settlement sites. This paper presents results
from a programme of stable carbon (d13C) and nitrogen (d15N) isotope analysis of fauna from two
major midden sites, Llanmaes in South Wales and Potterne in Wiltshire. The research aim is to
reconstruct husbandry strategies and foddering regimes, particularly concerning pigs, to better
understand how the challenges of raising large herds were met. Analysis produced exceptionally
wide-ranging results for pigs and other domesticates at both sites, particularly in terms of d15N
values, demonstrating that diverse foddering strategies were employed. Diversity in the late
Bronze Age pig foddering regimes indicates that the Neolithic husbandry practices (focusing on
woodland fodder) had not been abandoned, but that new husbandry methods (consumption of
household waste) were also being practised, which subsequently became more widely
established in the Iron Age. The heterogeneity of signatures suggests that animals may have
been husbanded in a piecemeal fashion at a local, household level. This in turn hints that fauna
may have been brought to these sites from households across the surrounding landscape, rather
than being husbanded by specialist producers in the vicinity of the middens."
Bookmarks Related papers MentionsView impact
Journal of the North …, 2009
Bookmarks Related papers MentionsView impact
The carbon isotopic characterisation of ruminant lipids associated with ceramic vessels has been ... more The carbon isotopic characterisation of ruminant lipids associated with ceramic vessels has been crucial for elucidating the origins and changing nature of pastoral economies. δ(13)C values of fatty acids extracted from potsherds are commonly compared with those from the dairy and carcass fats of modern domesticated animals to determine vessel use. However, the processing of wild ruminant products in pottery, such as deer, is rarely considered despite the presence of several different species on many prehistoric sites. To address this issue, the carbon isotope range of fatty acids from a number of red deer (Cervus elaphus) tissues, a species commonly encountered in the European archaeological record, was investigated. Lipids were extracted from 10 modern red deer tissues obtained from the Slowinski National Park (Poland). Fatty acids were fractionated, methylated and analysed by gas chromatography/combustion/isotope ratio mass spectrometry (GCCIRMS). The δ(13)C values of n-octadecanoic acid and n-hexadecanoic acid, and the difference between these values (Δ(13)C), were compared with those from previously published ruminant fats. Nine of the ten deer carcass fats measured have Δ(13)C values of less than -3.3‰, the threshold previously used for classifying dairy products. Despite considerable overlap, dairy fats from domesticated ruminants with Δ(13)C values less than -4.3‰ are still distinguishable. The finding has implications for evaluating pottery use and early pastoralism. The processing of deer tissues and our revised criteria should be considered, especially where there is other archaeological evidence for their consumption.
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Journal of Archaeological Science, 2009
Trou de Chaleux and Goyet are caves situated less than 30km apart in Belgium that contain stratif... more Trou de Chaleux and Goyet are caves situated less than 30km apart in Belgium that contain stratified Magdalenian artefacts and butchered faunal remains. Published radiocarbon dates suggest that both sites were contemporaneously occupied during to the Late-glacial interstadial. It has previously been suggested that the Trou de Chaleux Late-glacial faunal remains might be slightly older than those at Goyet Cave,
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Palaeogeography, …, Jan 1, 2012
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Through isotopic investigations of directly dated human remains recovered from the Eton College R... more Through isotopic investigations of directly dated human remains recovered from the Eton College Rowing Course we examine changes in diet from the Neolithic to the Roman period. The human isotope signatures point to a diet based on C3 terrestrial resources. A significant correlation is visible between human δ13C values and time, but no such trend is observed in δ15N. The animal isotope data from Eton are unevenly distributed making it difficult to determine if the human values mirror the animal values. To assess whether the results from Eton are typical we compare our results to isotope data from other British sites dating from the Neolithic to the Roman period. Across this time period we see a strong correlation between the mean δ15N of the humans and that of the main domesticated herbivores, with an offset of ~4.5‰ between the two. Thus the changes in the human isotope values are likely linked to changes in the isotopic signatures of the herbivores rather than changes in the protein composition of human diets. By contrast no clear temporal relationship is observed between the mean δ13C of the humans and that of the main domesticated herbivores, with an offset of ~1.4‰ between the two. There is however a weak correlation observed between the mean δ13C of the humans and that of the cattle, which may account for some of the variation in human δ13C values between sites. The absence of a strong correlation between mean human and animal δ13C suggests that the primary factor influencing human δ13C values between sites is dietary composition. The lack of co-variation between δ13C and δ15N is likely to reflect the different representation of dietary macronutrients. Given that the nitrogen results suggest that the animal protein consumption patterns are similar across sites, the human δ13C variation between sites is likely to reflect the plant portion of the diet.
Bookmarks Related papers MentionsView impact
Quaternary …, Jan 1, 2011
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…, Jan 1, 2011
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Palaeodietary studies typically focus on the analysis of bone collagen due to the limited availab... more Palaeodietary studies typically focus on the analysis of bone collagen due to the limited availability of plant remains. Isotopic analysis of plant remains, however, allow for a more extensive consideration of the contribution of plants to the human diet and can potentially provide information about the environment in which the crops were grown. This paper reports the results of carbon and nitrogen isotope analyses performed on charred barley and wheat grains recovered from pits within Danebury Iron Age hillfort. To the best of our knowledge, this is the first Iron Age site in Britain from which charred grains have been isotopically analysed. Our results suggest that cereals found at the hillfort were grown in several different environmental contexts. The isotope data demonstrate that the herbivores were not consuming a diet primarily based on grains as the d15N values of the grains are very similar to those of the herbivores. Palaeodietary investigations typically assume that humans eating plant protein only would have the same d15N value as the local herbivores. This assumption is clearly invalid at Danebury, where the humans and animals appear to have consumed either different parts of the same plants or different plants. Researchers typically interpret high differences between human and animal d15N values as indicative of diets high in animal protein, however where major plant resources have d15N values similar to those of the herbivores our ability to distinguish between plant and animal sources of protein in the diet is limited. Our research has demonstrated that whenever possible it is desirable to measure the isotopic signatures of potential major plant resources in order to understand past subsistence strategies.
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Bookmarks Related papers MentionsView impact
Palaeogeography, Palaeoclimatology, Palaeoecology, 2011
Over the last decade oxygen isotopes from herbivore teeth have frequently been used as a proxy fo... more Over the last decade oxygen isotopes from herbivore teeth have frequently been used as a proxy for palaeoclimatic conditions, yet our knowledge of how accurately the isotope signatures of an animal reflect seasonal climatic fluctuations remains limited. Our study on modern red ...
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