Validity of Radiocarbon Dates on Terrestrial Snail Shells

1970 ◽  
Vol 35 (1) ◽  
pp. 94-100 ◽  
Author(s):  
M. A. Tamers
Keyword(s):  
Stable Isotope ◽  
Radiocarbon Dating ◽  
The State ◽  
Archaeological Sites ◽  
Radiocarbon Dates ◽  
Snail Shell ◽  
Terrestrial Snail ◽  
Different Characteristics

AbstractRadiocarbon dating of terrestrial snail shells is examined. Three groups of samples, two from archaeological sites of Venezuela and one from the state of Texas, were taken as examples. The true ages were determined from radiocarbon dates on associated charcoal, and measurements on the snail shells allowed the errors to be determined. The groups showed completely different characteristics: 15 samples from Texas all had ages falsely old, 12 specimens of one Venezuelan group produced all correct dates, and another Venezuelan type with five samples gave dates all too recent. This study defines the directions and extents of errors for each group of snail shells, permitting them to be used as relatively reliable datable objectives in excavations where better materials are not available.The possibility of correcting the radiocarbon dates using carbon-13 concentrations is considered, and 24 measurements are presented. It is concluded that more than one factor can influence the stable isotope concentrations in each case, and, therefore, carbon-13 is not useful for the improvement of the accuracy of snail shell dates.

scholarly journals AMS Radiocarbon Dates of Kurgans Located On the Ust'-Yurt Plateau, Uzbekistan

Radiocarbon ◽  
2005 ◽  
Vol 47 (2) ◽  
pp. 235-241 ◽  
Author(s):  
Soren Blau ◽  
Vadim Yagodin
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Radiocarbon Dating ◽  
Skeletal Remains ◽  
Archaeological Sites ◽  
Late Prehistoric ◽  
Human Skeletal Remains ◽  
Radiocarbon Dates ◽  
Relative Dating ◽  
Ams Dates

Recent osteological analyses of archaeological human skeletal remains from the Ust'-Yurt Plateau, Uzbekistan, provided the opportunity to obtain samples for radiocarbon dating. The results of 18 accelerator mass spectrometry (AMS) dates are presented in this paper and provide the first absolute dates for late prehistoric and early historic archaeological sites in Uzbekistan. The AMS dates suggest that most sites are earlier than have been traditionally thought based on relative dating using artifact typologies.

PRELIMINARY RADIOCARBON DATING RESULTS OF BONE SAMPLES AT THE LAC-UFF, BRAZIL

Radiocarbon ◽  
2020 ◽  
pp. 1-12
Author(s):  
Fabiana Oliveira ◽  
Kita Macario ◽  
Karolayne Silva ◽  
Bruna Pereira ◽  
Ingrid Chanca ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Radiocarbon Dating ◽  
The State ◽  
Human Bone ◽  
Archaeological Sites ◽  
Large Molecular Weight ◽  
Brazilian Soils ◽  
Bone Preservation ◽  
Zinc Reduction ◽  
Sixth International

ABSTRACT Collagen extraction depends on the state of bone preservation, and the acidity of Brazilian soils often prevents the use of this material for radiocarbon dating. When available, however, bone samples constitute very important chronological records for both archaeological sites and natural depositional sites of specific animals. The extraction of collagen was performed using two filters, the first aiming to remove insoluble contaminants, and the second, a vivaspin ultrafilter 30KD to retain large molecular weight materials. The collagen was liofilized and converted to CO2 by combustion in sealed quartz tubes with CuO and Ag. The graphite was produced by zinc reduction in independently sealed Pyrex™ tubes. In order to verify the accuracy of this protocol, we analyzed a modern bone and four previously dated fragments, including those from the Sixth International Radiocarbon Intercomparison (SIRI), and a fragment of human bone from the Amourins site, a Brazilian shellmound. The results for the known age material are in agreement with the expected and the studied sector of Amourins shellmound was dated 4100–3900 years cal BP from a chronological model performed with charcoal dating found in different stratigraphic layers. Samples were dated at the radiocarbon laboratory of Universidade Federal Fluminense (LAC-UFF) in Brazil.

scholarly journals Radiocarbon Dating Sites of Itaparica Dam, São Francisco River Valley, Brazil

Radiocarbon ◽  
2006 ◽  
Vol 48 (3) ◽  
pp. 459-467
Author(s):  
L R P de Andrade Lima
Keyword(s):  
Radiocarbon Dating ◽  
Archaeological Sites ◽  
Adjacent Area ◽  
Dam Reservoir ◽  
Hunter Gatherers ◽  
Radiocarbon Dates ◽  
Reservoir Area ◽  
Sao Francisco River ◽  
São Francisco River ◽  
Lithic Artifacts

This paper reports radiocarbon dates of samples from archaeological sites in the Itaparica Dam region of the São Francisco River (Brazil). This region is important due to the evidence of its use by several prehistoric groups of hunter-gatherers. In the 1980s, a Brazilian state hydroelectric company (CHESF) engaged the federal universities of Bahia and Pernambuco to perform an archaeological rescue excavation at the Itaparica Dam reservoir area. This excavation allowed the collection of a large number of ceramics and lithic artifacts as well as fireplace charcoal. In this study, fireplace charcoal samples from the Bahia State riverside of the Itaparica Dam were selected and used for dating purposes. The 14C ages were between 3840 and 210 BP, and the values of δ13C range from −22.93 to −24.81%. The 14C dates, in addition to the archaeological findings, indicate that the presence of humans in the region was contemporary with the intermediate levels of older sites found in the adjacent area, and also indicate different settlement periods.

scholarly journals NEW DATA ON CHRONOLOGY OF NEOLITHIC CULTURE OF THE KAMA REGION

2021 ◽  
pp. 35-48
Author(s):  
E. L. Lychagina ◽  
◽  
A. A. Vybornov ◽  
M. A. Kulkova ◽  
◽  
...  
Keyword(s):  
River Basin ◽  
Radiocarbon Dating ◽  
Archaeological Sites ◽  
Original Material ◽  
Pottery Production ◽  
Radiocarbon Dates ◽  
Neolithic Culture ◽  
Animal Bones ◽  
River Region ◽  
Archaeological Materials

The article presents new radiocarbon dates obtained on the materials of the Volgo-Kamskaya and Kamskaya Neolithic cultures in the Kama River basin. In the paper, the data of original material for dating and methods were considered. Eleven new radiocarbon dates from eight Neolithic sites of region were obtained. The sites are located on the territory of the Upper Kama River basin (4 archaeological sites), the Kama-Vyatka basin (2 archaeological sites), and the Lower Kama River basin (2 archaeological sites). The main material for radiocarbon dating was the organics from pottery. Together with radiocarbon dates on organics from pottery, the dates on charcoal and animal bones were obtained. The dates on different organic materials have a good correlation. These results are new data for the early and developed stages of the Kamskaya culture. The earliest dates were obtained for unornamented pottery of the Volga-Kamskaya culture. This can be an evidence of priority of this culture in respect of pottery production in the Kamariver basin. This suggestion is confirmed by archaeological materials from neighbour regions. On other hand, the results of radiocarbon dating allow authors to conclude about synchronic existence of ceramic traditions with pinned and combed ornamentation from the middle of 6th to the middle of 5th millennium BC in region under consideration. However, the sites with pinned ornamented pottery appeared in the region earlier than the sites with ceramics ornamented by comb. The investigations gave the possibility to determine the time of appearance of sites with collarlike corolla pottery and pit-combed ornamented pottery in the Kama river region. The appearance of this type of ceramics in the region testifies to the contacts of the Kamskaya Neolithic culture community with people from the southern and eastern regions.

scholarly journals A New Radiocarbon Pretreatment Method for Molluscan Shell Using Density Fractionation of Carbonates in Bromoform

Radiocarbon ◽  
2010 ◽  
Vol 52 (3) ◽  
pp. 1301-1311 ◽  
Author(s):  
Christopher M Russo ◽  
Jennifer A Tripp ◽  
Katerina Douka ◽  
Thomas F G Higham
Keyword(s):  
Radiocarbon Dating ◽  
Separation Technique ◽  
Archaeological Sites ◽  
Density Fractionation ◽  
Pretreatment Method ◽  
Density Separation ◽  
Molluscan Shell ◽  
Archaeological Artifacts ◽  
Organic Remains

Coastal archaeological sites that lack organic remains for radiocarbon dating are often abundant sources of molluscan shells. As a substitute for materials such as bone and charcoal, shells can be analyzed with 14C dating to determine a site's age. Despite their being convenient, non-mobile archaeological artifacts, molluscan shells are plagued by several issues, including carbonate remodeling, in which aragonite in shells is converted to calcite as predicted by thermodynamics. We present here a carbonate density separation technique that addresses the issue of carbonate remodeling. Using a density fractionation with bromoform, aragonite concentrations are enriched in shells that have undergone significant remodeling. The technique has been applied to archaeological shells and has returned dates that are younger than those previously determined for the same shells.

Analysis of the Context and Contents of an Ulua-Style Marble Vase from the Palmarejo Valley, Honduras

2014 ◽  
Vol 25 (1) ◽  
pp. 82-100 ◽  
Author(s):  
E. Christian Wells ◽  
Karla L. Davis-Salazar ◽  
José E. Moreno-Cortes ◽  
Glenn S. L. Stuart ◽  
Anna C. Novotny
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Radiocarbon Dating ◽  
Isotope Analysis ◽  
Human Remains ◽  
Classic Period ◽  
Late Classic ◽  
Residential Group ◽  
Holistic Understanding ◽  
Political Economic

Ulúa-style marble vases played important social, political, economic, and religious roles in southern Mesoamerica during the seventh through eleventh centuries A.D. However, most such vessels known to archaeologists are part of looted collections or else were unearthed before the advent of modern archaeological practices. As a result, little is known about the context, use, and chronology of these objects. Recent investigations at the site of Palos Blancos in northwest Honduras discovered an Ulúa-style marble vase in an undisturbed mortuary context. Excavation of the burial context, along with bioarchaeological and stable isotope analysis of the human remains, suggests that the vase was placed as an offering, possibly to an ancestor of the residential group. Phosphate and pollen studies indicate that the vase once held a corn-based beverage . Radiocarbon dating of four charcoal samples from immediately below and adjacent to the vase yielded a range of dates from the beginning of the Late Classic period, ca.A.D. 600-800. Through analyses of the context and contents of the vase, this research contributes to a more holistic understanding of the use and meaning of Ulúa-style marble vases in southern Mesoamerica.

Calibrated Radiocarbon Dating at Keatley Creek: The Chronology of Occupation at a Complex Hunter-Gatherer Village

2003 ◽  
Vol 68 (4) ◽  
pp. 719-735 ◽  
Author(s):  
William C. Prentiss ◽  
Michael Lenert ◽  
Thomas A. Foor ◽  
Nathan B. Goodale ◽  
Trinity Schlegel
Keyword(s):  
British Columbia ◽  
Radiocarbon Dating ◽  
Climatic Factors ◽  
Climatic Warming ◽  
Radiocarbon Dates ◽  
Population Aggregation ◽  
Selective Environment

This paper provides an analysis of radiocarbon dates acquired during earlier and recent field seasons at the Keatley Creek site, southern British Columbia. Results indicate that early occupations predating 1900 cal. B.P. occurred, but were not likely associated with population aggregation and large housepits. The aggregated village appears to have emerged by approximately 1700 cal. B.P. and was abandoned at approximately 800 cal. B.P. A break in the occupational sequence is recognized at 1450-1350 cal. B.P. and one other short break may have occurred shortly after 1250 cal. B.P. Peak socioeconomic complexity appears to have been achieved between 1350 and 800 cal B.P. Climatic warming may have provided a selective environment favoring population aggregation and intensification during this time. The final abandonment of the Keatley Creek village appears to have been part of a regional phenomenon suggesting the possibility that climatic factors were important in this case as well.

Aquatic Radiocarbon Reservoir Offsets in the Southeastern Baltic

Radiocarbon ◽  
2015 ◽  
Vol 57 (4) ◽  
pp. 539-556 ◽  
Author(s):  
Gytis Piličiauskas ◽  
Carl Heron
Keyword(s):  
Stable Isotope ◽  
Bronze Age ◽  
Radiocarbon Dating ◽  
Bone Collagen ◽  
Curonian Lagoon ◽  
Human Bones ◽  
Ceramic Vessel ◽  
Pike Perch ◽  
Ceramic Vessels ◽  
Ams Dates

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.

scholarly journals Radiocarbon Dating of Calcined Bones: Where Does the Carbon Come from?

Radiocarbon ◽  
2009 ◽  
Vol 51 (2) ◽  
pp. 601-611 ◽  
Author(s):  
A Zazzo ◽  
J-F Saliège ◽  
A Person ◽  
H Boucher
Keyword(s):  
Radiocarbon Dating ◽  
Tooth Enamel ◽  
Skeletal Remains ◽  
Archaeological Sites ◽  
Carbonate Content ◽  
The Past ◽  
Mineral Fraction ◽  
Different Temperatures ◽  
C Value ◽  
Paleodietary Reconstruction

Over the past decade, radiocarbon dating of the carbonate contained in the mineral fraction of calcined bones has emerged as a viable alternative to dating skeletal remains in situations where collagen is no longer present. However, anomalously low δ13C values have been reported for calcined bones, suggesting that the mineral fraction of bone is altered. Therefore, exchange with other sources of carbon during heating cannot be excluded. Here, we report new results from analyses on cremated bones found in archaeological sites in Africa and the Near East, as well as the results of several experiments aiming at improving our understanding of the fate of mineral and organic carbon of bone during heating. Heating of modern bone was carried out at different temperatures, for different durations, and under natural and controlled conditions, and the evolution of several parameters (weight, color, %C, %N, δ13C value, carbonate content, crystallinity indexes measured by XRD and FTIR) was monitored. Results from archaeological sites confirm that calcined bones are unreliable for paleoenvironmental and paleodietary reconstruction using stable isotopes. Experimental results suggest that the carbon remaining in bone after cremation likely comes from the original inorganic pool, highly fractionated due to rapid recrystallization. Therefore, its reliability for 14C dating should be seen as close to that of tooth enamel, due to crystallographic properties of calcined bones.

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