scholarly journals Study of Bone Radiocarbon Dating Accuracy at the University of Arizona NSF Accelerator Facility for Radioisotope Analysis

Radiocarbon ◽  
1987 ◽  
Vol 29 (1) ◽  
pp. 24-44 ◽  
Author(s):  
Thomas W Stafford ◽  
A J T Jull ◽  
Klaus Brendel ◽  
Raymond C Duhamel ◽  
Douglas Donahue

Bone would seem to be an ideal material for14C dating because this calcified tissue contains 20 weight per cent protein. Fossil bone, however, can lose most of its original organic matter and frequently contains contaminants having different14C ages. Numerous14C dates on bone have been available to archaeologists and geologists but many age determinations have been inaccurate despite over 30 years of research in the field following the first14C age determinations on bone (Arnold & Libby, 1951). This situation remained unchanged until simple pretreatments were abandoned and more bone-specific fractions were isolated. The ideal solution is to use accelerator mass spectrometer14C dating, which facilitates the use of milligram-sized amounts of highly purified compounds—an approach impossible to pursue using conventional14C decay-counting methods.

Radiocarbon ◽  
1983 ◽  
Vol 25 (2) ◽  
pp. 719-728 ◽  
Author(s):  
D J Donahue ◽  
T H Zabel ◽  
A J T Jull ◽  
P E Damon ◽  
K H Purser

Tests of performance of the tandem accelerator mass spectrometer at the NSF Regional Facility at the University of Arizona are discussed. Results of measurements on some tree rings and on some archaeologic samples are presented.


Radiocarbon ◽  
1989 ◽  
Vol 31 (2) ◽  
pp. iii-iii
Author(s):  
Ajt Jull ◽  
Hans E Suess

Timothy Weiler Linick died on June 4th, 1989. He was a dedicated researcher, and an important part of the NSF Accelerator Facility for Radioisotope Analysis at the University of Arizona. He will be remembered for his care and attention to details, especially in the calculation and reporting of radiocarbon dates. He made important contributions to the fields of oceanography and tree-ring calibration of the 14C time scale.


Radiocarbon ◽  
1986 ◽  
Vol 28 (2A) ◽  
pp. 522-533 ◽  
Author(s):  
T W Linick ◽  
A J T Jull ◽  
L J Toolin ◽  
D J Donahue

Radiocarbon dating at the Arizona accelerator facility has improved substantially in the last three years. Since starting to use graphite targets (see Jull et al, 1986), we have been able to obtain routinely a precision of ca ± 1% (ca 80 yr) for relatively modern material. Our routine technique of tuning and operating the tandem accelerator mass spectrometer (TAMS) and our method of calculating 14C results are discussed in detail. Data on activity ratios of oxalic acid-II/oxalic-I are presented. Examples of the wide variety of projects on which we have collaborated are given. Brief discussions of three such projects are presented for our colleagues who were unable to attend this conference: an Arizona Indian archaeologic project, a study of megafaunal extinctions, and a study of the growth of phosphorite nodules on the sea floor off the Peruvian coast.


Radiocarbon ◽  
1989 ◽  
Vol 31 (03) ◽  
pp. 359-367 ◽  
Author(s):  
Robert M Kalin ◽  
Austin Long

The University of Arizona Radiocarbon Laboratory purchased a state-of-the-art LKB Quantulus LSC and placed it into a new underground counting chamber. We have investigated the performance of the Quantulus in this setting comparing different vial types, checking background sources and experimenting with sample size.


Radiocarbon ◽  
2018 ◽  
Vol 60 (2) ◽  
pp. 535-548 ◽  
Author(s):  
A J T Jull ◽  
C L Pearson ◽  
R E Taylor ◽  
J R Southon ◽  
G M Santos ◽  
...  

AbstractWe performed a new series of measurements on samples that were part of early measurements on radiocarbon (14C) dating made in 1948–1949. Our results show generally good agreement to the data published in 1949–1951, despite vast changes in technology, with only two exceptions where there was a discrepancy in the original studies. Our new measurements give calibrated ages that overlap with the known ages. We dated several samples at four different laboratories, and so we were also able to make a small intercomparison at the same time. In addition, new measurements on samples from other Egyptian materials used by Libby and co-workers were made at UC Irvine. Samples of tree rings used in the original studies (from Broken Flute Cave and Centennial Stump) were obtained from the University of Arizona Laboratory of Tree-Ring Research archive and remeasured. New data were compared to the original studies and other records.


Radiocarbon ◽  
1989 ◽  
Vol 31 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Robert M Kalin ◽  
Austin Long

The “C14” data base, designed and implemented at the University of Arizona Radiocarbon Dating Laboratory, uses Q&A, an artificial intelligence data file management program. The data entered into this data base are easily retrievable and exportable for submission to RADIOCARBON, and to the International Radiocarbon Data Base (IRDB). The use of artificial intelligence allows both novice and experienced computer operators to search and retrieve data with few key strokes and normal English sentences.


Radiocarbon ◽  
1993 ◽  
Vol 35 (2) ◽  
pp. 301-310 ◽  
Author(s):  
Alan R. Gagnon ◽  
Glenn A. Jones

In July 1986, an AMS radiocarbon target preparation laboratory was established at the Woods Hole Oceanographic Institution to produce graphite to be analyzed at the NSF-Accelerator Facility for Radioisotope Analysis at the University of Arizona (Tucson). By June 1991, 923 graphite targets had been prepared and 847 analyzed. Our lab procedures during this time included the careful documentation of weights of all starting samples, catalysts and final graphite yields, as well as the volume of CO2 gas evolved during CaCO3 hydrolysis or closed-tube organic carbon combustions. From these data, we evaluate the methods used in general and in our lab.


Radiocarbon ◽  
2009 ◽  
Vol 51 (1) ◽  
pp. 373-384 ◽  
Author(s):  
Steven W Leavitt ◽  
Bryant Bannister

The field of dendrochronology had a developmental “head start” of at least several decades relative to the inception of radiocarbon dating in the late 1940s, but that evolution was sufficiently advanced so that unique capabilities of tree-ring science could assure success of the 14C enterprise. The Laboratory of Tree-Ring Research (LTRR) at the University of Arizona played a central role in the cross-pollination of these disciplines by providing the first wood samples of exactly known age for the early testing and establishment of the “Curve of Knowns” by Willard Libby. From the 1950s into the early 1980s, LTRR continued to contribute dated wood samples (bristlecone pine and other wood species) to 14C research and development, including the discovery and characterization of de Vries/Suess “wiggles,” calibration of the 14C timescale, and a variety of tests to understand the natural variability of 14C and to refine sample treatment for maximum accuracy. The long and varied relationship of LTRR with 14C initiatives has continued with LTRR contributions to high-resolution studies through the 1990s and systematic efforts now underway that may eventually extend the bristlecone pine chronology back beyond its beginning 8836 yr ago as of 2009. This relationship has been mutualistic such that a half-century ago the visibility and stature of LTRR and dendrochronology were also elevated through their association with 14C-allied “hard sciences.”


Radiocarbon ◽  
2019 ◽  
Vol 62 (1) ◽  
pp. 63-74 ◽  
Author(s):  
M W Dee ◽  
S W L Palstra ◽  
A Th Aerts-Bijma ◽  
M O Bleeker ◽  
S de Bruijn ◽  
...  

ABSTRACTThe Centre for Isotope Research (CIO) at the University of Groningen has operated a radiocarbon (14C) dating laboratory for almost 70 years. In 2017, the CIO received a major upgrade, which involved the relocation of the laboratory to new purpose-built premises, and the installation of a MICADAS accelerator mass spectrometer. This period of transition provides an opportunity to update the laboratory’s routine procedures. This article addresses all of the processes and quality checks the CIO has in place for registering, tracking and pretreating samples for radiocarbon dating. Complementary updates relating to radioisotope measurement and uncertainty propagation will be provided in other forthcoming publications. Here, the intention is to relay all the practical information regarding the chemical preparation of samples, and to provide a concise explanation as to why each step is deemed necessary.


Sign in / Sign up

Export Citation Format

Share Document