scholarly journals New 14C Dates for the Early Natufian of El-Wad Terrace, Mount Carmel, Israel

Radiocarbon ◽  
2012 ◽  
Vol 54 (3-4) ◽  
pp. 813-822 ◽  
Author(s):  
Mina Weinstein-Evron ◽  
Reuven Yeshurun ◽  
Daniel Kaufman ◽  
Eileen Eckmeier ◽  
Elisabetta Boaretto
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Southern Levant ◽  
Radiocarbon Age ◽  
Cultural Affiliation ◽  
The Core ◽  
Integral Role ◽  
First Results ◽  
Age Determinations ◽  
Good Agreement

The Natufian culture of the southern Levant played an integral role in the transition from simple huntergatherers to food-producing societies of the Neolithic, but the major Natufian hamlets are currently poorly dated. Moreover, none of these complex, continuously occupied base camps have delivered an adequate number of dates to enable an in-depth delineation of intra-Natufian developments. This paper presents the first results of our dating program at el-Wad terrace, Mount Carmel (Israel), one of the major Natufian hamlets of the “core area” of this culture. Thirteen accelerator mass spectrometry (AMS) radiocarbon age determinations were obtained from 46 bone (both ungulate and human) and charcoal samples, originating in Early Natufian living surfaces, dwellings, and burials. The obtained dates are largely in agreement with the cultural affiliation of the samples (13–15 kyr cal BP). Two series of dates from different locations show good agreement with the stratigraphy. The ages of the burials clearly point to their being younger than the living surfaces seemingly associated with them. Presently, no burials may be linked with the major architectural phase of Early Natufian el-Wad. Our ongoing dating program and the processing of additional samples from refined contexts will help shed important light on the initial phases of the Natufian culture, habitation duration, intensity, and continuity, as well as the relationships between site features and stratigraphy.

scholarly journals Application of 14C AMS Dating to the Chronology of Holocene Glacier Fluctuations in the High Arctic, With Special Reference to Leffert Glacier, Ellesmere Island, Canada

Radiocarbon ◽  
1989 ◽  
Vol 31 (03) ◽  
pp. 570-578 ◽  
Author(s):  
Weston Blake
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
High Arctic ◽  
Ellesmere Island ◽  
Present Position ◽  
Outlet Glacier ◽  
Radiocarbon Age ◽  
Ams Dating ◽  
Climatic Cooling ◽  
Age Determinations

A series of radiocarbon age determinations obtained by Accelerator Mass Spectrometry (AMS) shows that the front of Leffert Glacier, a major outlet glacier from the Prince of Wales Icefield, Ellesmere Island, was 18+ km behind (west of) its present position for a period of at least 1500 radiocarbon years. A subsequent readvance occurred close to 2000 radiocarbon years ago, as a consequence of the climatic cooling that followed the warm Hypsithermal Interval. A number of other glaciers in the region appear to have behaved in similar fashion.

scholarly journals 41Ca Concentrations in Modern Bone and Their Implications for Dating

Radiocarbon ◽  
1989 ◽  
Vol 31 (03) ◽  
pp. 305-310 ◽  
Author(s):  
Roy Middleton ◽  
David Fink ◽  
Jeffrey Klein ◽  
Pankaj Sharma
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Isotope Enrichment ◽  
Terrestrial Rock ◽  
Order Of Magnitude ◽  
Cow Bone ◽  
Good Agreement

We have made the first measurements without pre-enrichment of 41Ca in terrestrial rock and bone samples using accelerator mass spectrometry. Although the results in tufa deposits from Egypt are in good agreement with the saturation value of 8×10-15 predicted by Raisbeck and Yiou (1979), the average 41Ca:40Ca ratio of 2×10-15 (range: 0.6 to 4.2×10-15) that we measure in modern bone is an order of magnitude lower than that obtained previously by Henning, et al (1987) on a cow bone that was measured using AMS following isotope enrichment. The low value and the variability (more than a factor of seven) of the 41Ca:40Ca ratio in modern bone make the possibility of dating bones using 41Ca unlikely.

Misunderstandings Concerning the Significance of AMS Background 14C Measurements

Radiocarbon ◽  
2018 ◽  
Vol 60 (3) ◽  
pp. 727-749
Author(s):  
R E Taylor ◽  
John R Southon ◽  
Guaciara M Santos
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Time Scale ◽  
Point Of View ◽  
General Validity ◽  
General Audience ◽  
Background Levels ◽  
Age Determinations

ABSTRACTWe consider one misconception of those who currently reject the general validity of radiocarbon (14C) age determinations older than, at most, 10,000 BP. There is an allegation that the presence of 14C reported by accelerator mass spectrometry (AMS) laboratories in their measurements of 14C infinite age (>100,000 years) organics used to define background levels, support their point of view. This article has been written for a general audience, primarily for those who have questions about the validity of these arguments. However, they may not be familiar with the literature relevant to providing a clear response to the claims of these individuals. We conclude that, in our view, of all of the possible explanations for the reports of the presence of 14C in these background samples, the least probable explanation has been advanced by those rejecting the validity of the 14C time scale in excess of, at most, 10,000 BP.

scholarly journals A Protocol for Radiocarbon Dating Tropical Subfossil Cave Guano

Radiocarbon ◽  
2009 ◽  
Vol 51 (3) ◽  
pp. 977-986 ◽  
Author(s):  
Christopher M Wurster ◽  
Michael I Bird ◽  
Ian Bull ◽  
Charlotte Bryant ◽  
Philippa Ascough
Keyword(s):  
Mass Spectrometry ◽  
Southeast Asia ◽  
Accelerator Mass Spectrometry ◽  
Radiocarbon Dating ◽  
Saturated Hydrocarbon ◽  
Lipid Fraction ◽  
Bulk Sample ◽  
Radiocarbon Dates ◽  
Organic Fractions ◽  
Age Determinations

We present accelerator mass spectrometry (AMS) radiocarbon dates on several organic fractions isolated from tropical guano deposits recovered from insular Southeast Asia. Differences were observed between 14C measurements made on bulk guano as well as bulk lipids, the saturated hydrocarbon fraction, solvent-extracted guano, and insect cuticles extracted from the same bulk sample. We infer that 14C dates from the bulk lipid fraction and saturated hydrocarbon fractions can be variably contaminated by exogenous carbon. In contrast, 14C measurements on solvent-extracted guano and isolated insect cuticles appear to yield the most robust age determinations.

scholarly journals Prime Lab: A Dedicated AMS Facility at Purdue University

Radiocarbon ◽  
1992 ◽  
Vol 34 (3) ◽  
pp. 447-451 ◽  
Author(s):  
David Elmore ◽  
F. A. Rickey ◽  
P. C. Simms ◽  
M. E. Lipschutz ◽  
K. A. Mueller ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Full Range ◽  
Planetary Science ◽  
Research Projects ◽  
Cosmogenic Radionuclides ◽  
The Earth ◽  
First Results ◽  
Purdue University ◽  
New Facility

A new facility for accelerator mass spectrometry has been established at Purdue University. First results have been obtained for 10Be and 36C1, and several internal research projects have been initiated. Plans are to become a national AMS facility to serve the Earth and planetary science communities for the full range of cosmogenic radionuclides.

scholarly journals 14C Ages of Bone Fractions from Armenian Prehistoric Sites

Radiocarbon ◽  
2010 ◽  
Vol 52 (2) ◽  
pp. 569-577 ◽  
Author(s):  
Alexander Cherkinsky ◽  
Christine Chataigner
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Organic Material ◽  
Separation Technique ◽  
Middle Paleolithic ◽  
Radiocarbon Dates ◽  
Bone Material ◽  
Younger Age ◽  
Archaeological Artifacts ◽  
Good Agreement

Prehistoric cultures in Armenia are still poorly known; thus, accelerator mass spectrometry (AMS) radiocarbon dates are invaluable in constructing an accurate chronology. Bone samples have been collected from sites representing the Middle Paleolithic, Chalcolithic, and Early Bronze periods. Most of the bone samples are poorly preserved. We describe the separation technique for the extraction of both the bioapatite and collagen fractions. In many cases where the bone had very low organic material content, the collagen fractions yielded a younger age, although the ages of bioapatite fractions were found to be in good agreement with associated archaeological artifacts. In cases where bone was well preserved, both fractions exhibited ages in good agreement with the artifacts. The accuracy of 14C dating of bone material always depends on its degree of preservation, and each case should be carefully evaluated to determine which fraction is less contaminated in order to accurately date a burial event.

scholarly journals Building the Radiocarbon Chronology for the Archaeological Site Ufa-II, Bashkortostan, Russia: Is this the Elusive “Bashkort” of Medieval Sources?

Radiocarbon ◽  
2013 ◽  
Vol 55 (3) ◽  
pp. 1278-1285
Author(s):  
Vladimir A Levchenko ◽  
Flarit A Sungatov
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Archaeological Site ◽  
Radiocarbon Dates ◽  
Site Occupation ◽  
Radiocarbon Chronology ◽  
First Time ◽  
Good Agreement

A suite of accelerator mass spectrometry (AMS) radiocarbon dates for the Ufa-II archaeological site in Bashkortostan, Russia, is obtained for the first time. Dating was done on charcoal samples from a sequence of cultural deposits collected during the 2011 digging season. An age-depth chronology is established using the Bayesian deposition General Outlier P_Sequence model. The oldest age for the site at the horizon immediately over the sterile ground was cal AD 137–237 (68% probability), corresponding to the beginning of site occupation. The youngest 14C date found was late 6th to early 7th century cal AD for the extensive planked boardwalks unearthed at the site. The 14C dates are in good agreement with archaeological determinations based on discovered artifacts.

scholarly journals Determination of the Radiocarbon Age of Parchment of the Vinland Map

Radiocarbon ◽  
2002 ◽  
Vol 44 (1) ◽  
pp. 45-52 ◽  
Author(s):  
D J Donahue ◽  
J S Olin ◽  
G Harbottle
Keyword(s):  
Mass Spectrometry ◽  
Atlantic Ocean ◽  
Confidence Level ◽  
Accelerator Mass Spectrometry ◽  
Yale University ◽  
Rare Book ◽  
Radiocarbon Age ◽  
The One ◽  
Age Range

The Vinland Map, drawn on a 27.8 × 41.0 cm parchment bifolium, is housed in the Beinecke Rare Book and Manuscript Library at Yale University. In the northwest Atlantic Ocean, it shows “the Island of Vinland, discovered by Bjarni and Leif in company.” Skelton, Marston, and Painter (Skelton et al. 1965, 1995) firmly argued the map's authenticity, associating it with the Council of Basle (AD 1431–1449), that is, half a century before Columbus's voyage. Nevertheless, vigorous scholarly questioning of the map's authenticity has persisted (Washburn 1966; McCrone 1974; Olin and Towe 1976; Cahill et al. 1987; McCrone 1988; Towe 1990). We have determined the precise radiocarbon age of the map's parchment by accelerator mass spectrometry (AMS). The one-sigma calibrated calendrical date range is AD 1434 ± 11 years: the 95% confidence level age range is AD 1411–1468.

scholarly journals Counting Statistics and Ion Interval Density in AMS

Radiocarbon ◽  
2004 ◽  
Vol 46 (3) ◽  
pp. 1103-1109 ◽  
Author(s):  
John S Vogel ◽  
Ted Ognibene ◽  
Magnus Palmblad ◽  
Paula Reimer
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Temporal Distribution ◽  
Counting Statistics ◽  
Random Nature ◽  
Radiocarbon Calibration ◽  
Age Determinations

Confidence in the precisions of accelerator mass spectrometry (AMS) and decay measurements must be comparable for the application of the radiocarbon calibration to age determinations using both technologies. We confirmed the random nature of the temporal distribution of 14C ions in an AMS spectrometer for a number of sample counting rates and properties of the sputtering process. The temporal distribution of ion counts was also measured to confirm the applicability of traditional counting statistics.

scholarly journals Marine Turtle Bones from an Archaeological Site in Polynesia Yield Reliable Age Determinations

Radiocarbon ◽  
1990 ◽  
Vol 32 (2) ◽  
pp. 143-147 ◽  
Author(s):  
T S Dye
Keyword(s):  
Mass Spectrometry ◽  
Sample Size ◽  
Accelerator Mass Spectrometry ◽  
South Pacific ◽  
Archaeological Site ◽  
Marine Turtle ◽  
Long Distance ◽  
Marine Turtles ◽  
Ams Dating ◽  
Age Determinations

Accelerator mass spectrometry dating of three 50g samples of marine turtle bone from the basal cultural stratum of the Tongoleleka archaeological site, Lifuka Island, Kingdom of Tonga, South Pacific yields results that agree with conventional 14C dates on marine shell. A method for calibrating these dates that takes into account the long distance migrations of marine turtles in the South Pacific is proposed. A sample size greater than 50g is recommended for routine AMS dating of marine turtle bone.

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