New accelerator mass spectrometry radiocarbon ages for the Mazama tephra layer from Kootenay National Park, British Columbia, Canada

1997 ◽  
Vol 34 (9) ◽  
pp. 1202-1209 ◽  
Author(s):  
D. J. Hallett ◽  
L. V. Hills ◽  
J. J. Clague

Charcoal fragments recovered from the Mazama air-fall tephra layer in cores from Dog and Cobb lakes, Kootenay National Park, British Columbia, yielded accelerator mass spectrometry ages of 6720 ± 70 and 6760 ± 70 14C years BP, respectively. These two new ages, together with other previously published radiocarbon ages on charcoal and twig fragments from Mazama air-fall deposits, indicate that the climactic eruption of Mount Mazama occurred 6730 ± 40 14C years BP.

2007 ◽  
Vol 50 (1) ◽  
pp. 73-80 ◽  
Author(s):  
C. Richard Harington ◽  
Alain Plouffe ◽  
Hélène Jetté

ABSTRACT Fragmentary but massive left and right horncores, found with eight post-cranial bones, from a clay unit underlying a diamicton of the last (Fraser) glaciation at Chuchi Lake, British Columbia probably represents an individual giant bison (Bison cf. B. latifrons). A sample of bone from one of the horncores yielded an accelerator mass spectrometry (AMS) radiocarbon date of 30 740 ± 220 BP, whereas overlapping dates from two other laboratories on an associated humerus are 34 800 ± 420 BP and 35 480 ± 1080 BP. Despite the discrepancy between horncore and humerus dates, they are in accord with the suspected stratigraphie age of the clay unit whence they came. Analysis of pollen from that clay unit indicates that bison with massive horns once occupied an open forest in the vicinity. Probably giant bison and Columbian mammoths (incorporating paleoenvironmental evidence found with the nearby, penecontemporaneous Babine Lake mammoth) shared lake-dotted open forest to shrub tundra range in what is now central British Columbia toward the close of the Middle Wisconsinan (Olympia Nonglacial Interval). The Chuchi Lake specimen is important because it is the first indication of giant bison from British Columbia, and it appears to be one of the latest known survivors of this species.


1985 ◽  
Vol 22 (5) ◽  
pp. 790-791 ◽  
Author(s):  
Rolf W. Mathewes ◽  
J. S. Vogel ◽  
J. R. Southon ◽  
D. E. Nelson

Accelerator mass spectrometry was used to test whether part of eastern Graham Island was ice free at the height of late Wisconsin glaciation on mainland British Columbia. An accelerator radiocarbon date of 14 700 ± 700 years on a small twig conforms with two conventional dates that suggested that the Cape Ball region of Graham Island was deglaciated by about 15 000 radiocarbon years ago.


Radiocarbon ◽  
2007 ◽  
Vol 49 (1) ◽  
pp. 123-129 ◽  
Author(s):  
Yaroslav V Kuzmin

The problem of a hiatus at about 6100–5300 BP (about 4900–4200 cal BC) in the prehistoric chronology of the Cis-Baikal region in Siberia is discussed. Based on a critical evaluation of existing evidence, there was no discontinuity found in the cultural sequence between the Kitoi and Serovo/Glazkovo complexes of the Neolithic, and the proposed “hiatus” may be an artifact based on underestimation of solid data. Conventional 14C dates are presented that were generated in the 1980s to early 2000s for Cis-Baikal prehistoric burial grounds, and were later dated by the accelerator mass spectrometry (AMS).


Radiocarbon ◽  
2021 ◽  
pp. 1-12
Author(s):  
G Quarta ◽  
M Molnár ◽  
I Hajdas ◽  
L Calcagnile ◽  
I Major ◽  
...  

ABSTRACT The application of accelerator mass spectrometry radiocarbon (AMS 14C) dating in forensics is made possible by the use of the large excursion of the 14C concentration in the post-WWII terrestrial atmosphere due to nuclear testing as a reference curve for data calibration. By this approach high-precision analyses are possible on samples younger than ∼70 years. Nevertheless, the routine, widespread application of the method in the practice of forensics still appears to be limited by different issues due to possible complex interpretation of the results. We present the results of an intercomparison exercise carried out in the framework of an International Atomic Energy Agency (IAEA) CRP-Coordinated Research Project between three AMS laboratories in Italy, Hungary, and Switzerland. Bone and ivory samples were selected with ages spanning from background (>50 ka) to 2018. The results obtained allow us to assess the high degree of reproducibility of the results and the remarkable consistency of the experimental determinations.


Radiocarbon ◽  
2001 ◽  
Vol 43 (2A) ◽  
pp. 249-254 ◽  
Author(s):  
J N Lanting ◽  
A T Aerts-Bijma ◽  
J van der Plicht

When dating unburnt bone, bone collagen, the organic fraction of the bone, is used. Collagen does not survive the heat of the cremation pyre, so dating of cremated bone has been considered impossible. Structural carbonate in the mineral fraction of the bone, however, survives the cremation process. We developed a method of dating cremated bone by accelerator mass spectrometry (AMS), using this carbonate fraction. Here we present results for a variety of prehistoric sites and ages, showing a remarkable success rate for this method.


Radiocarbon ◽  
2021 ◽  
pp. 1-19
Author(s):  
Federico Manuelli ◽  
Cristiano Vignola ◽  
Fabio Marzaioli ◽  
Isabella Passariello ◽  
Filippo Terrasi

ABSTRACT The Iron Age chronology at Arslantepe is the result of the interpretation of Luwian hieroglyphic inscriptions and archaeological data coming from the site and its surrounding region. A new round of investigations of the Iron Age levels has been conducted at the site over the last 10 years. Preliminary results allowed the combination of the archaeological sequence with the historical events that extended from the collapse of the Late Bronze Age empires to the formation and development of the new Iron Age kingdoms. The integration into this picture of a new set of radiocarbon (14C) dates is aimed at establishing a more solid local chronology. High precision 14C dating by accelerator mass spectrometry (AMS) and its correlation with archaeobotanical analysis and stratigraphic data are presented here with the purpose of improving our knowledge of the site’s history and to build a reliable absolute chronology of the Iron Age. The results show that the earliest level of the sequence dates to ca. the mid-13th century BC, implying that the site started developing a new set of relationships with the Levant already before the breakdown of the Hittite empire, entailing important historical implications for the Syro-Anatolian region at the end of the 2nd millennium BC.


Radiocarbon ◽  
2021 ◽  
pp. 1-7
Author(s):  
Corina Solís ◽  
Efraín Chávez ◽  
Arcadio Huerta ◽  
María Esther Ortiz ◽  
Alberto Alcántara ◽  
...  

ABSTRACT Augusto Moreno is credited with establishing the first radiocarbon (14C) laboratory in Mexico in the 1950s, however, 14C measurement with the accelerator mass spectrometry (AMS) technique was not achieved in our country until 2003. Douglas Donahue from the University of Arizona, a pioneer in using AMS for 14C dating, participated in that experiment; then, the idea of establishing a 14C AMS laboratory evolved into a feasible project. This was finally reached in 2013, thanks to the technological developments in AMS and sample preparation with automated equipment, and the backing and support of the National Autonomous University of Mexico and the National Council for Science and Technology. The Mexican AMS Laboratory, LEMA, with a compact 1 MV system from High Voltage Engineering Europa, and its sample preparation laboratories with IonPlus automated graphitization equipment, is now a reality.


Radiocarbon ◽  
2019 ◽  
Vol 62 (4) ◽  
pp. 891-899 ◽  
Author(s):  
Adam Sookdeo ◽  
Bernd Kromer ◽  
Ulf Büntgen ◽  
Michael Friedrich ◽  
Ronny Friedrich ◽  
...  

ABSTRACTAdvances in accelerator mass spectrometry have resulted in an unprecedented amount of new high-precision radiocarbon (14C) -dates, some of which will redefine the international 14C calibration curves (IntCal and SHCal). Often these datasets are unaccompanied by detailed quality insurances in place at the laboratory, questioning whether the 14C structure is real, a result of a laboratory variation or measurement-scatter. A handful of intercomparison studies attempt to elucidate laboratory offsets but may fail to identify measurement-scatter and are often financially constrained. Here we introduce a protocol, called Quality Dating, implemented at ETH-Zürich to ensure reproducible and accurate high-precision 14C-dates. The protocol highlights the importance of the continuous measurements and evaluation of blanks, standards, references and replicates. This protocol is tested on an absolutely dated German Late Glacial tree-ring chronology, part of which is intercompared with the Curt Engelhorn-Center for Archaeometry, Mannheim, Germany (CEZA). The combined dataset contains 170 highly resolved, highly precise 14C-dates that supplement three decadal dates spanning 280 cal. years in IntCal, and provides detailed 14C structure for this interval.


Radiocarbon ◽  
1989 ◽  
Vol 31 (03) ◽  
pp. 305-310 ◽  
Author(s):  
Roy Middleton ◽  
David Fink ◽  
Jeffrey Klein ◽  
Pankaj Sharma

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.


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