scholarly journals Radiocarbon Activity Variation in Dated Tree Rings Grown in Mackenzie Delta

Radiocarbon ◽  
1983 ◽  
Vol 25 (2) ◽  
pp. 205-212 ◽  
Author(s):  
C Y Fan ◽  
Chen Tie-Mei ◽  
Yun Si-Xun ◽  
Dai Kai-Mei
Keyword(s):  
Tree Rings ◽  
Liquid Scintillation ◽  
White Spruce ◽  
Mackenzie Delta ◽  
Sunspot Numbers ◽  
Physical Implication ◽  
Activity Variation ◽  
Peking University ◽  
Data Points ◽  
History Department

Forty-five tree rings (1881–1925) were taken from a white spruce grown near Campbell River in Mackenzie Delta, Canada, for the measurement of 14C activity variation. Because of the narrowness of the rings, 2 and sometimes 3 rings were combined to yield a total of 21 specimens. The 14C content in these specimens was measured with a liquid scintillation-PM tube counter system of the History Department of Peking University. The data points exhibit a 10‰ variation, anti-correlated with sunspot numbers. The physical implication is discussed.

scholarly journals Radiocarbon Activity Variation in Dated Tree Rings Grown in Mackenzie Delta

Radiocarbon ◽  
1986 ◽  
Vol 28 (2A) ◽  
pp. 300-305 ◽  
Author(s):  
C Y Fan ◽  
Chen Tie-Mei ◽  
Yun Si-Xun ◽  
Dai Kai-Mei
Keyword(s):  
Solar Activity ◽  
Tree Rings ◽  
Solar Flares ◽  
Activity Cycle ◽  
White Spruce ◽  
Solar Activity Cycle ◽  
Mackenzie Delta ◽  
Activity Variation

We measured the Δ14C values in 57 rings (from AD 1824 to 1880) of a white spruce grown in Mackenzie Delta (68°N, 130°W), as part of our continuing study of the Δ14C variation related to solar activities. The values exhibit a 10‰ fluctuation with an 11-year periodicity anti-correlated with the solar activity cycle. We also measured the Δ14C values in 6 rings (from AD 1940 to 1945). The abnormally high value in the 1943 ring may be due to two large solar flares occurring in 1942.

scholarly journals Climatic Signals in δ13C and δ18O of Tree-rings from White Spruce in the Mackenzie Delta Region, Northern Canada

2009 ◽  
Vol 41 (4) ◽  
pp. 497-505 ◽  
Author(s):  
Trevor J. Porter ◽  
Michael F. J. Pisaric ◽  
Steven V. Kokelj ◽  
Thomas W. D. Edwards
Keyword(s):  
Tree Rings ◽  
White Spruce ◽  
Mackenzie Delta ◽  
Delta Region ◽  
Northern Canada ◽  
Climatic Signals ◽  
Δ13c And Δ18o

scholarly journals Spring-summer temperatures since AD 1780 reconstructed from stable oxygen isotope ratios in white spruce tree-rings from the Mackenzie Delta, northwestern Canada

2013 ◽  
Vol 42 (3-4) ◽  
pp. 771-785 ◽  
Author(s):  
Trevor J. Porter ◽  
Michael F. J. Pisaric ◽  
Robert D. Field ◽  
Steven V. Kokelj ◽  
Thomas W. D. Edwards ◽  
...  
Keyword(s):  
Oxygen Isotope ◽  
Tree Rings ◽  
White Spruce ◽  
Isotope Ratios ◽  
Mackenzie Delta ◽  
Stable Oxygen Isotope ◽  
Oxygen Isotope Ratios ◽  
Summer Temperatures ◽  
Stable Oxygen

scholarly journals Instrumentation and Software for Low-Level Liquid Scintillation Counting Radiocarbon Dating

Radiocarbon ◽  
1992 ◽  
Vol 34 (3) ◽  
pp. 374-380 ◽  
Author(s):  
Guan Sanyuan ◽  
Xie Yuanming
Keyword(s):  
Liquid Scintillation Counting ◽  
Radiocarbon Dating ◽  
Liquid Scintillation ◽  
Detection Efficiency ◽  
Scintillation Counting ◽  
Vertebrate Paleontology ◽  
Marine Geology ◽  
Important Research ◽  
High Background ◽  
Peking University

In China, the development of 14C dating is closely related to that of liquid scintillation counting (LSC). New demands are continuously made on LSC by 14C dating, and at the same time, the development of LSC promotes 14C dating. Benzene synthesis for 14C sample preparation was first developed in China in 1974 by the 14C Laboratory of the Department of History, Peking University. This has laid the foundation for 14C dating by β counting with LS counters. Initially, we used a modified conventional LS counter. Despite its poor detection efficiency and high background, it did make a great contribution to 14C dating and LSC in China. Additional 14C laboratories were established for the fields of archaeology, geology, geography, vertebrate paleontology, marine geology and seismology, for which 14C dating is becoming an important research tool. At present, over 50 14C laboratories have been established in China; 90% of the labs use LS counters for β counting, most of which are manufactured in China. 14C dating in China has been primarily concerned with sample synthesis techniques. Since 1979, we have developed three types of LS counters. One is of conventional design; the others are with anticoincidence shielding. We describe here an anticoincidence-shielded LS counter.

scholarly journals Bomb-Produced 14C in Tree Rings

Radiocarbon ◽  
1992 ◽  
Vol 34 (3) ◽  
pp. 753-756 ◽  
Author(s):  
Dai Kaimei ◽  
Qian Youneng ◽  
C. Y. Fan
Keyword(s):  
Tree Ring ◽  
Tree Rings ◽  
Liquid Scintillation ◽  
Equilibrium Distribution ◽  
Latitude Zone ◽  
Novaya Zemlya ◽  
Longitudinal Mixing ◽  
Oak Tree ◽  
Global Equilibrium ◽  
Northern And Southern Hemispheres

The 14C content in 1961–1967 and 1970–1983 tree rings of a spruce grown in Dailing, China (47°N, 129°E) was measured by liquid scintillation. As a result of USSR bomb tests at Novaya Zemlya (72°N, 53°E), Δ14C values rose dramatically from 250‰ in 1961 to a maximum 909‰ in 1964, and then gradually decreased to 238‰ in 1983. We compared Δ14C values in the rings of an oak tree grown at 43°N, 74°W and that of a pine grown at 49°N, 9°E, and atmospheric Δ14C values in both northern and southern hemispheres. We observe that: 1) annual tree rings grown in the same latitude zone have the same Δ14C values, reflecting rapid longitudinal mixing of the atmosphere; 2) atmospheric 14C concentrations reached a global equilibrium distribution at the end of 1968, and tree ring 14C content reflects atmospheric 14C concentration; 3) 1976–1982 rings of the Dailing spruce show excessive 14C, likely due to the effect of 1976 and 1980 Chinese bomb tests; 4) Δ14C decreases exponentially, halving every 17 yr.

scholarly journals 14C AMS Dating the Transition from the Paleolithic to the Neolithic in South China

Radiocarbon ◽  
1995 ◽  
Vol 37 (2) ◽  
pp. 245-249 ◽  
Author(s):  
Sixun Yuan ◽  
Guoxing Zhou ◽  
Zhiyu Guo ◽  
Zimo Zhang ◽  
Shijun Gao ◽  
...  
Keyword(s):  
South China ◽  
Radiocarbon Dating ◽  
Liquid Scintillation ◽  
Scintillation Counter ◽  
Neolithic Period ◽  
Autonomous Region ◽  
Guangxi Zhuang Autonomous Region ◽  
Peking University ◽  
Rapid Transition ◽  
Ams Dating

To study the transition from the Paleolithic to the Neolithic period and its duration, samples of charcoal, bone, flowstone and shells excavated from Bailiandong and Miaoyan caves, Guangxi Zhuang autonomous region, South China were dated using the Peking University AMS facility and liquid scintillation counter. The remains excavated from these sites show typical characteristics of the transition from the Paleolithic to the Neolithic. Radiocarbon dating results show a rapid transition from ca. 20 to 10 ka bp.

scholarly journals Short-Term Variations in Radiocarbon Concentration with the 11-Year Solar Cycle

Radiocarbon ◽  
1983 ◽  
Vol 25 (2) ◽  
pp. 259-266 ◽  
Author(s):  
Pavel Povinec ◽  
A A Burchuladze ◽  
S V Pagava
Keyword(s):  
Solar Cycle ◽  
Tree Ring ◽  
Tree Rings ◽  
Statistical Evaluation ◽  
Time Shift ◽  
Solar Cycles ◽  
Average Amplitude ◽  
Short Term ◽  
Sunspot Numbers

Previous investigations on short-term 14C variations in tree rings are compared with 14C measurements in wine samples. The comparison is made for 4 solar cycles (1903–1944) with the same method of statistical evaluation of measured results. The average amplitude of Δ14C variations as observed by various authors in tree-ring samples is ca 2 ± 1 ‰; however, wine samples show an average amplitude of 4.3 ± 1.6 ‰. The anticorrelation dependence of Δ14C on Wolf sunspot numbers was observed with a time shift between W maxima and Δ14C minima of 3–5 yr for different solar cycles.

The evolution and maintenance of white spruce woodlands on the Mackenzie Delta, N.W.T., Canada

Ecography ◽  
1988 ◽  
Vol 11 (4) ◽  
pp. 248-258 ◽  
Author(s):  
C. M. Pearce ◽  
D. McLennan ◽  
L. D. Cordes
Keyword(s):  
White Spruce ◽  
Mackenzie Delta

scholarly journals Comparison of 14C Ages Between LSC and AMS Measurements of Choukai Jindai Cedar Tree Rings at 2600 cal BP

Radiocarbon ◽  
2010 ◽  
Vol 52 (3) ◽  
pp. 895-900 ◽  
Author(s):  
Yui Takahashi ◽  
Hirohisa Sakurai ◽  
Kayo Suzuki ◽  
Taiichi Sato ◽  
Shuichi Gunji ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Tree Rings ◽  
Liquid Scintillation ◽  
Measurement Methods ◽  
Scintillation Counting ◽  
Age Difference ◽  
Data Sets ◽  
Data Set ◽  
The Difference ◽  
Good Agreement

Radiocarbon ages of Choukai Jindai cedar tree rings growing in the excess era of 14C concentrations during 2757–2437 cal BP were measured using 2 types of 14C measurement methods, i.e. liquid scintillation counting (LSC) and accelerator mass spectrometry (AMS). The difference between the 2 methods is 3.7 ± 5.2 14C yr on average for 61 single-year tree rings, indicating good agreement between the methods. The Choukai data sets show a small sharp bump with an average 14C age of 2497.1 ± 3.0 14C yr BP during 2650–2600 cal BP. Although the profile of the Choukai LSC data set compares well with that of IntCal04, having a 14C age difference of 4.6 ± 5.3 14C yr on average, the Choukai LSC 14C ages indicate variability against the smoothed profile of IntCal04.

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