scholarly journals Radiocarbon Dating of Deep-Sea Sediments: A Comparison of Accelerator Mass Spectrometer and Beta-Decay Methods

Radiocarbon ◽  
1989 ◽  
Vol 31 (2) ◽  
pp. 105-116 ◽  
Author(s):  
G A Jones ◽  
A J T Jull ◽  
T W Linick ◽  
D J Donahue

Radiocarbon dating (Libby, 1955) has been an important tool in the marine sciences since the early 1950s (eg, Arrhenius, Kjellberg & Libby, 1951; Ericson et al, 1956; Broecker, Ewing & Heezen, 1960; Emery & Bray, 1962) and the basic principles and analytic procedures of the method have changed little. In the late 1970s, the Accelerator Mass Spectrometer (AMS) method of 14C dating was developed (Bennett et al, 1977, 1978), the major advantages being that samples several thousand times smaller than needed for beta-decay counting can be dated, and analysis time is reduced to ca 1 hr from the 1–6 days needed for beta-decay methods.

2020 ◽  
Vol 17 (4) ◽  
pp. 635-638
Author(s):  
S. A. Rastigeev ◽  
A. D. Goncharov ◽  
V. F. Klyuev ◽  
E. S. Konstantinov ◽  
V. V. Parkhomchuk ◽  
...  

MRS Bulletin ◽  
1992 ◽  
Vol 17 (1) ◽  
pp. 53-60 ◽  
Author(s):  
D.C. Stulik ◽  
D.J. Donahue

Since the development of 14C dating by W.F. Libby in the 1940s and 1950s, the method has proved to be the best absolute method for chronometric dating of organic and some carbon-containing inorganic materials. It has become an essential research tool for both archaeologists and geologists. Even broader application horizons have been opened to radiocarbon dating by use of the accelerator mass spectrometer, which allows routine analysis of submilligram samples. Art curatorship and art conservation directly benefit from this development.There are pronounced similarities between application of radiocarbon dating in archaeology and art research but there are also major differences which make it difficult to simply take a methodology developed for archaeological research and apply it directly to radiocarbon dating of art objects.In both fields the application of dating techniques focuses on dating an object of unknown age or cross-checking the age of an object previously dated by other methods.


1993 ◽  
Vol 13 (3) ◽  
pp. 219-247 ◽  
Author(s):  
Mary M. Farrell ◽  
Jeffery F. Burton

Rock art analysis has been used both to provide insight into prehistoric symbolism and ceremony, and to measure prehistoric interaction and communication. But chronological control, essential to distinguishing functional or social differences from temporal differences, has been difficult to establish. No one method of dating has yet proven completely reliable or applicable. Accelerator mass spectrometer radiocarbon dating, at the Tom Ketchum Cave pictograph site in southeastern Arizona, provides one of the first examples of direct independent dating of rock art. The dates suggest the pictographs may have been created during a time when subsistence patterns were shifting from Archaic hunter and gatherer traditions to more agriculture-based subsistence. The Tom Ketchum Cave artists broke from the abstract style more common in the region to represent game animals and hunters, perhaps to ensure success in a disappearing way of life.


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.


Radiocarbon ◽  
2010 ◽  
Vol 52 (2) ◽  
pp. 263-271 ◽  
Author(s):  
P Naysmith ◽  
G T Cook ◽  
S P H T Freeman ◽  
E M Scott ◽  
R Anderson ◽  
...  

In 2003, a National Electrostatics Corporation (NEC) 5MV tandem accelerator mass spectrometer was installed at SUERC, providing the radiocarbon laboratory with 14C measurements to 4–5‰ repeatability. In 2007, a 250kV single-stage accelerator mass spectrometer (SSAMS) was added to provide additional 14C capability and is now the preferred system for 14C analysis. Changes to the technology and to our operations are evident in our copious quality assurance data: typically, we now use the 134-position MC-SNICS source, which is filled to capacity. Measurement of standards shows that spectrometer running without the complication of on-line δ13C evaluation is a good operational compromise. Currently, 3‰ 14C/13C measurements are routinely achieved for samples up to nearly 3 half-lives old by consistent sample preparation and an automated data acquisition algorithm with sample random access for measurement repeats. Background and known-age standard data are presented for the period 2003–2008 for the 5MV system and 2007–2008 for the SSAMS, to demonstrate the improvements in data quality.


Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 196
Author(s):  
Jiangbo Ren ◽  
Yan Liu ◽  
Fenlian Wang ◽  
Gaowen He ◽  
Xiguang Deng ◽  
...  

Deep-sea sediments with high contents of rare-earth elements and yttrium (REY) are expected to serve as a potential resource for REY, which have recently been proved to be mainly contributed by phosphate component. Studies have shown that the carriers of REY in deep-sea sediments include aluminosilicate, Fe-Mn oxyhydroxides, and phosphate components. The ∑REY of the phosphate component is 1–2 orders of magnitude higher than those of the other two carriers, expressed as ∑REY = 0.001 × [Al2O3] − 0.002 × [MnO] + 0.056 × [P2O5] − 32. The sediment P2O5 content of 1.5% explains 89.1% of the total variance of the sediment ∑REY content. According to global data, P has a stronger positive correlation with ∑REY compared with Mn, Fe, Al, etc.; 45.5% of samples have a P2O5 content of less than 0.25%, and ∑REY of not higher than 400 ppm. The ∑REY of the phosphate component reaches n × 104 ppm, much higher than that of marine phosphorites and lower than that of REY-phosphate minerals, which are called REY-rich phosphates in this study. The results of microscopic observation and separation by grain size indicate that the REY-rich phosphate component is mainly composed of bioapatite. When ∑REY > 2000 ppm, the average CaO/P2O5 ratio of the samples is 1.55, indicating that the phosphate composition is between carbonate fluoroapatite and hydroxyfluorapatite. According to a knowledge map of sediment elements, the phosphate component is mainly composed of P, Ca, Sr, REY, Sc, U, and Th, and its chemical composition is relatively stable. The phosphate component has a negative Ce anomaly and positive Y anomaly, and a REY pattern similar to that of marine phosphorites and seawater. After the early diagenesis process (biogeochemistry, adsorption, desorption, transformation, and migration), the REY enrichment in the phosphate component is completed near the seawater/sediment interface. In the process of REY enrichment, the precipitation and enrichment of P is critical. According to current research progress, the REY enrichment is the result of comprehensive factors, including low sedimentation rate, high ∑REY of the bottom seawater, a non-carbonate depositional environment, oxidation conditions, and certain bottom current conditions.


Author(s):  
Dingquan Wang ◽  
Jianxin Wang ◽  
Runying Zeng ◽  
Jie Wu ◽  
Shijia V. Michael ◽  
...  
Keyword(s):  
Deep Sea ◽  

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