Improved radiocarbon dating for contaminated archaeological bone collagen, silk, wool and hair samples via cross-flow nanofiltrated amino acids

2013 ◽  
Vol 27 (18) ◽  
pp. 2039-2050 ◽  
Author(s):  
Mathieu Boudin ◽  
Pascal Boeckx ◽  
Peter Vandenabeele ◽  
Mark Van Strydonck
Radiocarbon ◽  
2013 ◽  
Vol 55 (2) ◽  
pp. 445-463 ◽  
Author(s):  
F Brock ◽  
V Geoghegan ◽  
B Thomas ◽  
K Jurkschat ◽  
T F G Higham

Archaeological bones are now routinely dated in many radiocarbon laboratories through the extraction of “collagen.” Methods for “collagen” extraction vary, and several laboratories now apply an ultrafiltration step after gelatinization to extract the higher molecular weight (usually >10 or 30kDa) fraction for dating, thereby removing low molecular weight contaminants. Ultrafiltration has been demonstrated to result in products that are easier to handle and have more acceptable C:N ratios, and in some instances can result in significantly improved (generally older) 14C dates when compared to non-ultrafiltered products from the same bone. Although it has been suggested that ultrafiltration removes potential contaminants such as short-chain degraded collagen and other peptides and amino acids, fulvic acids, and salts, there remains little published evidence to support this. This paper presents data from a pilot study investigating the most suitable techniques with which to study the products of the routine “collagen” extraction procedures employed at the Oxford Radiocarbon Accelerator Unit (ORAU) (modified Longin followed by ultrafiltration). The preliminary data demonstrates that the final product of “collagen” extraction at ORAU appears to be an aggregate consisting of a range of proteins of different molecular weights, including collagen, as well as some other organic matter and inorganic species. Ultrafiltration is removing some, but not all, of the <30kDa fraction from the samples. Further work to investigate the nature of this aggregate and how best to improve the efficiency of “collagen” extraction procedures is discussed.


Radiocarbon ◽  
2010 ◽  
Vol 52 (2) ◽  
pp. 620-634 ◽  
Author(s):  
James S O McCullagh ◽  
Anat Marom ◽  
Robert E M Hedges

Since the development of accelerator mass spectrometry (AMS) for radiocarbon dating in the late 1970s, its ability to date small samples of bone has been of huge importance in archaeology and Quaternary paleoecology. The conventional approach to sample preparation has been to extract and gelatinize protein, which is then combusted and graphitized for analysis. However, this “bulk protein” can contain a heterogeneous mixture of non-collagenous molecules, including humic acids and other soil components that may be of a different age than the bone and therefore affect the accuracy of its 14C date. Sample pretreatment methods have been an important area of development in recent years but still show inadequacies for the dating of severely contaminated bone. The idea of isolating and dating individual compounds such as single amino acids, to improve dating accuracy, has been discussed in the literature since the 1960s. Hydroxyproline, for example, makes up over 10% of bone collagen but is extremely rare in most other animal proteins, increasing the chances of its presence being endogenous to the individual being dated. Its successful isolation has therefore been considered a potential “gold standard” for dating archaeological bone; however, extracting and suitably purifying single amino acids from bone has proved a challenging task.


Radiocarbon ◽  
2014 ◽  
Vol 56 (2) ◽  
pp. 603-617 ◽  
Author(s):  
Mathieu Boudin ◽  
Pascal Boeckx ◽  
Peter Vandenabeele ◽  
Mark van Strydonck

Excavations in the cathedral of Tournai revealed two sepultures, which were identified by the excavators as those of bishops because of their special location in the cathedral. One burial was assigned to Baldwin I, who died in AD 1068, because (1) a ring with the inscription “BAL” was found and (2) a funeral stone with text was present on top of the grave mentioning the name Baldewinus. The second burial probably belongs to Radbot II, who was the successor of Baldwin I, and died in AD 1098. Both burials contained textiles (silk), the skeleton, a wooden pastoral staff, and human hair was still present on the skull of what was presumed to be Radbot II. All the protein-containing materials were degraded and/or contaminated. Standard sample pretreatment methods were not able to remove all the contaminants. Single and double cross-flow nanofiltration of the hydrolyzed protein-containing materials were performed. The sample quality for radiocarbon dating was improved and14C data revealed interesting and surprising results. The14C dates of the wooden pastoral staff and permeate femur confirm that the skeleton and tomb belong to bishop Baldwin I. The14C dates of hair and permeate skull indicate that the skeleton may indeed belong to bishop Radbot II. The younger14C dates of the wooden pastoral staff and silk samples indicate a postburial disturbance of the site burial during the 12th–13th century.


Radiocarbon ◽  
2014 ◽  
Vol 56 (02) ◽  
pp. 603-617 ◽  
Author(s):  
Mathieu Boudin ◽  
Pascal Boeckx ◽  
Peter Vandenabeele ◽  
Mark van Strydonck

Excavations in the cathedral of Tournai revealed two sepultures, which were identified by the excavators as those of bishops because of their special location in the cathedral. One burial was assigned to Baldwin I, who died in AD 1068, because (1) a ring with the inscription “BAL” was found and (2) a funeral stone with text was present on top of the grave mentioning the name Baldewinus. The second burial probably belongs to Radbot II, who was the successor of Baldwin I, and died in AD 1098. Both burials contained textiles (silk), the skeleton, a wooden pastoral staff, and human hair was still present on the skull of what was presumed to be Radbot II. All the protein-containing materials were degraded and/or contaminated. Standard sample pretreatment methods were not able to remove all the contaminants. Single and double cross-flow nanofiltration of the hydrolyzed protein-containing materials were performed. The sample quality for radiocarbon dating was improved and14C data revealed interesting and surprising results. The14C dates of the wooden pastoral staff and permeate femur confirm that the skeleton and tomb belong to bishop Baldwin I. The14C dates of hair and permeate skull indicate that the skeleton may indeed belong to bishop Radbot II. The younger14C dates of the wooden pastoral staff and silk samples indicate a postburial disturbance of the site burial during the 12th–13th century.


1999 ◽  
Vol 64 (3) ◽  
pp. 444-454 ◽  
Author(s):  
Vance T. Holliday ◽  
Eileen Johnson ◽  
Thomas W. Stafford

Plainview and Firstview are two of the principal post-Folsom Paleoindian artifact assemblages on the Great Plains, but good radiometric age control for these artifact styles is relatively poor, due in part to lack of reliable age control on the type collections. This study reports the results of AMS-radiocarbon dating of specific amino acids from Bison antiquus bone associated with the type Plainview and Firstview assemblages from the Plainview and Olsen-Chubbuck sites, respectively. Seven samples of bone and teeth from Plainview produced a surprisingly wide array of ages. As a result, the age of the bone bed and the type Plainview collection remain uncertain, but it is most likely ≥ 10,000 B.P. (but late or post-Folsom) given the dating and stratigraphic relationships at Plainview and other sites. Seven samples of bone from Olsen-Chubbuck yielded a tight cluster of ages averaging ca 9400 B.P., fitting well with other dated Firstview features on the Southern Plains. These results show that much better age control from more sites is needed in order to understand the Paleoindian record. AMS-radiocarbon dating of specific amino acids from bone has revolutionized such issues of chronology in archaeology, but like any other method, it can provide confusing results and must be used in conjunction with other chronometric data.


2007 ◽  
Vol 72 (4) ◽  
pp. 719-734 ◽  
Author(s):  
Michael P. Richards ◽  
Sheila Greer ◽  
Lorna T. Corr ◽  
Owen Beattie ◽  
Alexander Mackie ◽  
...  

We report here on the results of AMS dating and isotopic analysis of the frozen human remains named Kwaday Dän Ts'inchí and associated materials recovered from a glacier located in Northwest British Columbia, Canada in 1999. The isotopic analysis of bone collagen (bulk and single amino acids) from the individual indicates a strongly marine diet, which was unexpected given the location of this find, more than 100 km inland eroding out of a high elevation glacier; however, bulk hair and bone cholesterol isotopic values indicate a shift in diet to include more terrestrial foods in the year before death. The radiocarbon dating is not straightforward, as there are difficulties in determining the appropriate marine correction for the human remains, and the spread of dates on the associated artifacts clearly indicates that this was not a single use site. By combining the most recent date on a robe worn by Kwaday Dän Ts'inchi with direct bone collagen dates we conclude that the individual likely dates to between cal A.D. 1670 to 1850, which is in the pre-(or early) European contact period for this region.


Radiocarbon ◽  
2015 ◽  
Vol 57 (4) ◽  
pp. 539-556 ◽  
Author(s):  
Gytis Piličiauskas ◽  
Carl Heron

The aim of this article is to discuss radiocarbon dating offsets due to freshwater and marine reservoir effects (FRE and MRE, respectively) in the southeastern Baltic. Thirty-six 14C dates from Lithuanian coastal and inland Subneolithic, Neolithic, and Bronze Age sites as well as two Mesolithic-Neolithic cemeteries are presented here. Accelerator mass spectrometry (AMS) dates, sometimes paired or tripled, have been obtained on samples of various origin, foodcrusts, or visible charred deposits adhering to the surfaces of ceramic vessel walls were also dated and investigated for stable isotope signals. The results argue for a significant freshwater component in the food processed in ceramic vessels during the Subneolithic and Neolithic. Paired dating of ungulate and human bones at the Spiginas and Donkalnis cemeteries (6300–1900 cal BC) does not suggest an FRE, although stable isotope data on human bone collagen strongly suggest a large input of freshwater food in the diet. An FRE in the order of 320–510 yr was estimated for the Šventoji paleolagoon around 3000 cal BC. At the same time, the FRE of the Curonian Lagoon could be larger as implied by large apparent 14C ages of modern pike-perch (981 ± 30 BP) and bream (738 ± 30 BP) bones as well as “foodcrust” offsets (650–530 yr) at Nida (3500–2500 cal BC). An MRE of 190 ± 43 yr was estimated for the southeastern coast of the Littorina Sea according to offsets between dates of seal bones and terrestrial samples at Nida and Šventoji. Any FRE at Lake Kretuonas remains uncertain due to the limited work to date.


Author(s):  
Stephen Black ◽  
Katherine Spradley ◽  
Michelle Hamilton

The discovery of two well preserved human crania in a crevice overlooking a spring fed creek near Austin, Texas, led to medico legal, archeological, and bioanthropological investigations aimed at understanding the context and biological affinity of the crania. Archeological excavations uncovered no evidence that the crania were interred in the crevice during prehistoric times. Skeletal analysis showed they were of Native American ancestry. Radiocarbon dating indicated they are contemporary to one another and probably date to the seventh or eighth century A.D. Measured stable isotopic rations of carbon ( 13 C/ 12 C) and nitrogen ( 15 N/ 14 N) derived from human bone collagen samples from the crania are not consistent with other burial populations from the region, having higher nitrogen values than all other comparative samples. The crania also showed polish from repeated handling and several of the molars in one cranium had been glued in place. Taken together, these lines of evidence suggest the crania were removed from an unknown locality outside the Central Texas region, kept in a private collection, and placed in the crevice recently.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7174
Author(s):  
John P. Hart ◽  
Robert S. Feranec ◽  
Timothy J. Abel ◽  
Jessica L. Vavrasek

Isotopic analysis of dog (Canis lupus familiaris) bone recovered from archaeological sites as proxies for human bone is becoming common in North America. Chronological placement of the dogs is often determined through radiocarbon dating of dog bone. The Great Lakes, their tributaries, and nearby lakes and streams were important fisheries for Native Americans prior to and after sustained European presence in the region. Carbon entering the food web in freshwater systems is often not in full isotopic equilibrium with the atmosphere, giving rise to spuriously old radiocarbon ages in fish, other aquatic organisms, and their consumers. These freshwater reservoir offsets (FROs) have been noted on human and dog bone in several areas of the world. Here we report the results of multi-tracer Bayesian dietary modeling using δ15N and δ13C values on dog bone collagen from mid-fifteenth to mid-sixteenth-century Iroquoian village sites at the headwaters of the St. Lawrence River, New York, USA. Results indicate that fish was an important component of dog diets. A comparison of radiocarbon dates on dog bone with dates on deer bone or maize from the same sites indicate FROs ranging from 97 ± 24 to 220 ± 39 14Cyr with a weighted mean of 132 ± 8 14Cyr. These results suggest that dog bone should not be used for radiocarbon dating in the absence of modeling to determine fish consumption and that previously reported radiocarbon dates on human bone from the larger region are likely to have FROs given the known importance of fish in regional human diets.


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