Utilization of δ13C, δ15N, and δ34S Analyses to Understand 14C Dating Anomalies within a Late Viking Age Community in Northeast Iceland

Radiocarbon ◽  
2014 ◽  
Vol 56 (2) ◽  
pp. 811-821 ◽  
Author(s):  
Kerry L Sayle ◽  
Gordon T Cook ◽  
Philippa L Ascough ◽  
Hildur Gestsdóttir ◽  
W Derek Hamilton ◽  
...  

Previous stable isotope studies of modern and archaeological faunal samples from sites around Lake Mývatn, within the Mývatnssveit region of northeast Iceland, revealed that an overlap existed between the δ15N ranges of terrestrial herbivores and freshwater fish, while freshwater biota displayed δ13C values that were comparable with marine resources. Therefore, within this specific ecosystem, the separation of terrestrial herbivores, freshwater fish, and marine fish as components of human diet is complicated when only δ13C and δ15N are measured. δ34S measurements carried out within a previous study on animal bones from Skútustaoir, an early Viking age settlement on the south side of Lake Mývatn, showed that a clear offset existed between animals deriving their dietary resources from terrestrial, freshwater, and marine reservoirs. The present study focuses on δ13C, δ15N, and δ34S analyses and radiocarbon dating of human bone collagen from remains excavated from a churchyard at Hofstaoir, 5 km west of Lake Mývatn. The results demonstrate that a wide range of δ34S values exist within individuals, a pattern that must be the result of consumption of varying proportions of terrestrial-, freshwater-, and marine-based resources. For that proportion of the population with 14C ages that apparently predate the well-established first human settlement of Iceland (landnám) circa AD 871 ± 2, this has enabled us to explain the reason for these anomalously old ages in terms of marine and/or freshwater 14C reservoir effects.

Radiocarbon ◽  
2014 ◽  
Vol 56 (02) ◽  
pp. 811-821 ◽  
Author(s):  
Kerry L Sayle ◽  
Gordon T Cook ◽  
Philippa L Ascough ◽  
Hildur Gestsdóttir ◽  
W Derek Hamilton ◽  
...  

Previous stable isotope studies of modern and archaeological faunal samples from sites around Lake Mývatn, within the Mývatnssveit region of northeast Iceland, revealed that an overlap existed between the δ15N ranges of terrestrial herbivores and freshwater fish, while freshwater biota displayed δ13C values that were comparable with marine resources. Therefore, within this specific ecosystem, the separation of terrestrial herbivores, freshwater fish, and marine fish as components of human diet is complicated when only δ13C and δ15N are measured. δ34S measurements carried out within a previous study on animal bones from Skútustaoir, an early Viking age settlement on the south side of Lake Mývatn, showed that a clear offset existed between animals deriving their dietary resources from terrestrial, freshwater, and marine reservoirs. The present study focuses on δ13C, δ15N, and δ34S analyses and radiocarbon dating of human bone collagen from remains excavated from a churchyard at Hofstaoir, 5 km west of Lake Mývatn. The results demonstrate that a wide range of δ34S values exist within individuals, a pattern that must be the result of consumption of varying proportions of terrestrial-, freshwater-, and marine-based resources. For that proportion of the population with14C ages that apparently predate the well-established first human settlement of Iceland (landnám) circa AD 871 ± 2, this has enabled us to explain the reason for these anomalously old ages in terms of marine and/or freshwater14C reservoir effects.


Radiocarbon ◽  
2012 ◽  
Vol 54 (3-4) ◽  
pp. 749-760 ◽  
Author(s):  
N Shishlina ◽  
E Zazovskaya ◽  
J van der Plicht ◽  
V Sevastyanov

Bronze Age human and animal bone collagen from several steppe Bronze Age cultures (i.e. Early Catacomb, East and West Manych Catacomb, and Lola cultures) shows large variations in δ13C and δ15N values. In general, we observed that the older the sample, the lower the δ13C and δ15N values. We hypothesize that more positive values of δ13C and δ15N are caused by change in diet and a more arid climate. For ancient sheep during drier periods of the Early Catacomb, East and West Manych Catacomb, and Lola cultures, we observed 2 groups with different C and N isotopic compositions, reflecting consumption of different types of fodder. During periods of aridization, C4 and C3 plants with high δ15N values appeared in the vegetation, also influencing bone collagen values. Human bones show reservoir effects, caused by aquatic diet components. These effects can be quantified by paired dating of human bone and associated terrestrial samples. Reservoir corrections have revised chronologies for the region. Some paired dates do not reveal reservoir effects. This can be explained in 2 alternative ways. One is that the human diet did not include aquatic components; rather, the diet was based on C3 vegetation with high δ15N values (13–15‰), and flesh/milk of domesticated animals. An alternative explanation is that humans consumed food from freshwater resources without reservoir effects.


2019 ◽  
Author(s):  
Bryan C. Lougheed

Abstract. The systematic bioturbation of single particles (such as foraminifera) within deep-sea sediment archives leads to the apparent smoothing of any temporal signal as record by the downcore, discrete-depth mean signal. This smoothing is the result of the systematic mixing of particles from a wide range of depositional ages into the same discrete depth interval. Previous sediment models that simulate bioturbation have specifically produced an output in the form of a downcore, discrete-depth mean signal. Palaeoceanographers analysing the distribution of single foraminifera specimens from sediment core intervals would be assisted by a model that specifically evaluates the effect of bioturbation upon single specimen populations. Taking advantage of recent increases in computer memory, the single-specimen SEdiment AccuMUlation Simulator (SEAMUS) was created in Matlab, whereby large arrays of single specimens are simulated. This simulation allows researchers to analyse the post-bioturbation age heterogeneity of single specimens contained within discrete-depth sediment core intervals, and how this heterogeneity is influenced by changes in sediment accumulation rate (SAR), bioturbation depth (BD) and species abundance. The simulation also assigns a realistic 14C activity to each specimen, by considering the dynamic Δ14C history of the Earth and temporal changes in reservoir age. This approach allows for the quantification of possible significant artefacts arising when 14C dating multi-specimen samples with heterogeneous 14C activity. Users may also assign additional desired carrier signals to specimens (e.g., stable isotopes, trace elements, temperature, etc.) and consider a second species with an independent abundance. Finally, the model can simulate a virtual palaeoceanographer by randomly picking whole specimens (whereby the user can set the percentage of older, broken specimens) of a prescribed sample size from discrete depths, after which virtual laboratory 14C dating and 14C calibration is carried out within the model.


Radiocarbon ◽  
2012 ◽  
Vol 54 (3-4) ◽  
pp. 879-886 ◽  
Author(s):  
Fiona Brock ◽  
Rachel Wood ◽  
Thomas F G Higham ◽  
Peter Ditchfield ◽  
Alex Bayliss ◽  
...  

A recent study into prescreening techniques to identify bones suitable for radiocarbon dating from sites known for poor or variable preservation (Brock et al. 2007, 2010a) found that the percent nitrogen (%N) content of whole bone powder was the most reliable indicator of collagen preservation. Measurement of %N is rapid, requires little preparation or material, and is relatively cheap. The technique reduces the risk of needlessly sampling valuable archaeological objects, as well as saving time and money on their unsuccessful pretreatment prior to dating. This method of prescreening is now regularly used at the Oxford Radiocarbon Accelerator Unit (ORAU). In the original study, linear regression analysis of data from 100 bones from 12 Holocene sites across southern England showed that when 0.76% N was chosen as a threshold, 84% of bones were successfully identified as containing sufficient (i.e. >1%) or insufficient (i.e. <1%) collagen for dating. However, it has been observed that for older, Pleistocene bones the failure rate may be higher, possibly due to the presence of more degraded, short-chain proteins that pass through the ultrafilters used in pretreatment, resulting in lower yields. Here, we present linear regression analysis of data from nearly 600 human and animal bones, antlers, and teeth, from a wide range of contexts and ages, to determine whether the 0.76% threshold identified in the previous study is still applicable. The potential of carbon:nitrogen atomic weight ratios (C:N) of whole bone to predict collagen preservation is also discussed.


2009 ◽  
pp. S39-S45
Author(s):  
J Pickova

The need of better labelling of fats in processed animal origin products is urgent. The lack of information makes it possible to exclude n-3 fatty acids in preparations of foods. The higher fat content, the higher n-6/n-3 ratio seems to be a rule. It is desirable to broaden the labelling into which oils have been used when foods are processed. The dietary balance of n-6 and n-3 fatty acids is important for homeostasis and normal development in humans. The ratio between n-6/n-3 fatty acids suggested to be evolutionary developed is between 1 and 4. The main conclusion is that the fat sources used during processing and preparation of convenient foods have the largest impact on the food FA content and composition. A proposal is therefore that this should be declared on the product label especially the n-3 FA content. It is also of large importance to increase consumption of freshwater fish fed suitable feeds containing n-3 fatty acids in central Europe to enable a generally lower n-6/n-3 ratio in the human diet. Therefore optimizing feeds to freshwater fish in culture is urgent and important.


1993 ◽  
Vol 39 (4) ◽  
pp. 635-640 ◽  
Author(s):  
J Risteli ◽  
I Elomaa ◽  
S Niemi ◽  
A Novamo ◽  
L Risteli

Abstract We developed a radioimmunoassay (RIA) for the carboxy-terminal telopeptides of type I collagen (ICTP), cross-linked with the helical domain of another type I collagen molecule, after isolation from human femoral bone. The cross-linked peptide was liberated by digesting insoluble, denatured bone collagen either with bacterial collagenase or with trypsin, and purified by two successive reversed-phase separations on HPLC, with monitoring of pyridinoline-specific fluorescence. The purity of the peptide was verified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and its origin in the type I collagen fibers was determined by amino-terminal amino acid sequencing. Polyclonal antibodies and a separation reagent containing second antibody and polyethylene glycol are used in the RIA. An immunologically identical, somewhat larger antigen is present in human serum; its concentration increases in multiple myeloma and in rheumatoid arthritis. The ICTP antigen seems to be cleared from the circulation by the kidneys, because glomerular filtration rates that are two-thirds of normal or less are associated with increased circulating ICTP concentrations. The CVs of the method are between 3% and 8% for a wide range of concentrations. The analysis of 40 serum samples can be completed in 4 h.


2017 ◽  
Vol 10 (8) ◽  
pp. 2123-2135 ◽  
Author(s):  
Chelsea Budd ◽  
Necmi Karul ◽  
Songül Alpaslan-Roodenberg ◽  
Alfred Galik ◽  
Rick Schulting ◽  
...  

1989 ◽  
Vol 126 (4) ◽  
pp. 333-337 ◽  
Author(s):  
B. W. D. Yardley ◽  
G. E. Lloyd

AbstractUpper amphibolite facies dolomite and calcite marbles from the Dalradian Connemara Marble Formation of western Ireland display a wide range of textures when viewed in cathodoluminescence that are invisible in transmitted light. Examples observed include growth zones in calcite that appear to represent the infilling of a metamorphic secondary porosity, produced by the large reduction in solid volume accompanying growth of tremolite from dolomite and quartz. Retrograde phenomena are widespread, and include both carbonate pseudomorphs after tremolite and coarse veining, which is in optical continuity with peak metamorphic calcite but otherwise indistinguishable from it. Admixture of such widely differing calcite types may account for scatter in some stable isotope studies of marbles.


2018 ◽  
Vol 98 ◽  
pp. 187-218
Author(s):  
Joanna Ostapkowicz ◽  
Alison Roberts ◽  
Jevon Thistlewood ◽  
Fiona Brock ◽  
Alex C Wiedenhoeft ◽  
...  

This paper focuses on the material study (radiocarbon dating, wood identification and strontium isotope analyses) of four large ‘India occidentali’ clubs, part of the founding collections of the Ashmolean Museum, in Oxford, and originally part of John Tradescant’s ‘Ark’, in Lambeth (1656). During the seventeenth century, the term ‘India occidentali/occidentales’ referred not only to the ‘West Indies’ (its literal translation), but to the Americas as a whole; hence, the Ashmolean clubs and, indeed, thecforty examples of similarly large, decorated clubs known in international museum collections had no firm provenance and lacked even the most basic information. Previous attempts at attribution, based on stylistic comparisons with nineteenth- to twentieth-century Brazilian and Guyanese clubs, have proved inconclusive given the unique features of this club style, raising the intriguing possibility that these may be exceptionally rare examples of ‘Island Carib’ (Kalinago) material culture, particularly as images of such clubs appear in seventeenth-century ethnographic accounts from the Lesser Antilles. This paper provides new data for these poorly known objects from early collections, revealing not only the type of wood from which they were carved (Platymisciumsp. andBrosimumcfguianense) and their probable dates of manufacture (c AD1300–1640), but also their possible provenance (strontium results are consistent with a possible range from Trinidad south to French Guiana).


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