scholarly journals Gif Natural Radiocarbon Measurements IX

Radiocarbon ◽  
1982 ◽  
Vol 24 (3) ◽  
pp. 291-343 ◽  
Author(s):  
Georgette Delibrias ◽  
Marie-Thérèse Guillier ◽  
Jacques Labeyrie
Keyword(s):  
Standard Deviation ◽  
South America ◽  
Oxalic Acid ◽  
West Africa ◽  
Sea Level ◽  
Half Life ◽  
Sea Level Variations ◽  
Geologic Samples ◽  
Modern Standard

The following list includes 14C measurements of geologic samples, the majority of which pertain to sea-level variations, and of archaeologic samples mainly from France, West Africa, and South America. Most of the dates were measured between 1972 and 1973 when installations were not modified. The technique used is described in Radiocarbon, 1972, v 14, p 280–320. Dates were calculated using the 14C half-life of 5568 years; modern standard is 0.95 of the NBS oxalic acid. Reported errors are one standard deviation for 2000 minutes measurements.

scholarly journals Tartu Radiocarbon Dates XI

Radiocarbon ◽  
1990 ◽  
Vol 32 (1) ◽  
pp. 99-105 ◽  
Author(s):  
Evald Ilves
Keyword(s):  
Standard Deviation ◽  
Oxalic Acid ◽  
Half Life ◽  
Liquid Scintillation ◽  
Standard Sample ◽  
Single Channel ◽  
Radiocarbon Dates ◽  
Geologic Samples ◽  
Modern Standard

This list includes dates of geologic samples measured using a single-channel liquid scintillation 14C counter at the Geochemical and Statistical Laboratory, Tartu, Estonian SSR. Our modern standard is made of benzene enriched in 14C and its activity is checked with NBS oxalic acid standard sample. Dates are given in conventional radiocarbon years, based on the Libby half-life of 5570 ± 30 yr. AD 1950 is the reference year. Errors refer only to 1σ standard deviation calculated from count rates involved.

scholarly journals Tartu Radiocarbon Dates XIII

Radiocarbon ◽  
1994 ◽  
Vol 36 (1) ◽  
pp. 153-158
Author(s):  
Arvi Liiva ◽  
Ilze Loze
Keyword(s):  
Standard Deviation ◽  
Oxalic Acid ◽  
Liquid Scintillation Counting ◽  
Half Life ◽  
Liquid Scintillation ◽  
Standard Sample ◽  
Scintillation Counting ◽  
Radiocarbon Dates ◽  
Academy Of Sciences ◽  
Modern Standard

This date list reports dates of archaeological samples of Mesolithic and Neolithic sites of Estonia, Latvia and Lithuania. We use liquid scintillation counting at the Geochemical and Statistical Laboratory of the Institute of Zoology and Botany, Estonian Academy of Sciences. Our modern standard is benzene enriched in 14C and its activity is checked with an NBS oxalic acid standard sample. Dates are given in conventional 14C years, based on the Libby half-life of 5570 ± 30 yr. AD 1950 is the reference year. Errors are based on one standard deviation calculated from count rates.

scholarly journals National Taiwan University Radiocarbon Measurements II

Radiocarbon ◽  
1973 ◽  
Vol 15 (2) ◽  
pp. 345-349 ◽  
Author(s):  
Yuin-Chi Hsu ◽  
Muh-Chen Chou ◽  
Yi-Chuan Hsu ◽  
Song-Yun Lin ◽  
Shih-Chong Lu
Keyword(s):  
Standard Deviation ◽  
Oxalic Acid ◽  
Proportional Counter ◽  
Half Life ◽  
Statistical Nature ◽  
Radiocarbon Dates ◽  
Disintegration Process ◽  
Modern Standard

The C14 dates given below have been obtained by counting CO2 at 2 atm pressure in a 1 L proportional counter. Details of procedure are given in our previous list (R., 1970, v. 12, p. 187–192). Radiocarbon dates in this list are based on 95% of activity of NBS oxalic acid as the modern standard and were calculated using 5570 yr as the half-life of C14. Errors quoted with the dates are standard deviation originating from the statistical nature of radioactive disintegration process. Results obtained during 1970 and 1971 are described here.

scholarly journals University of Miami Radiocarbon Dates IX

Radiocarbon ◽  
1977 ◽  
Vol 19 (2) ◽  
pp. 326-331 ◽  
Author(s):  
D Piepgras ◽  
J J Stipp
Keyword(s):  
Standard Deviation ◽  
Half Life ◽  
Radiocarbon Dates ◽  
Partial List ◽  
Geologic Samples ◽  
University Of Miami ◽  
Modern Standard

The following radiocarbon measurements are a partial list of geologic samples dated since September 1975. The technique used is described in R, v 18, p 210-220. Dates are calculated using a 14C half-life of 5568 yr and errors are reported as one standard deviation. This includes only the counting errors on the sample, background and modern standard.

scholarly journals Lódź Radiocarbon Dates II

Radiocarbon ◽  
1986 ◽  
Vol 28 (3) ◽  
pp. 1102-1109 ◽  
Author(s):  
Andrzej Kanwiszer ◽  
Paweł Trzeciak
Keyword(s):  
Standard Deviation ◽  
Proportional Counter ◽  
Half Life ◽  
Radiocarbon Dates ◽  
Geologic Samples ◽  
Modern Standard

The following list consists of dates of archaeologic and geologic samples measured from January 1981 to December 1982. Measurements were continued with the same proportional counter system, pretreatment procedure, methane preparation, measurement, and calculation, as described previously (Kanwiszer & Trzeciak, 1984). Ages were computed on the 14C half-life of 5568 ± 30 years. Precision is reported as one standard deviation based only on statistical counting uncertainties in the measurement of the background, NBS modern standard, and sample activities. The dates are not corrected for 13C fractionation. Descriptions and comments are based on information supplied by submitters of samples.

scholarly journals Gif Natural Radiocarbon Measurements VII

Radiocarbon ◽  
1972 ◽  
Vol 14 (2) ◽  
pp. 280-320 ◽  
Author(s):  
G. Delibrias ◽  
M. T. Guillier ◽  
J. Labeyrie
Keyword(s):  
Stainless Steel ◽  
Oxalic Acid ◽  
Proportional Counter ◽  
Half Life ◽  
Ofhc Copper ◽  
Geologic Samples ◽  
Modern Standard

C14 dates reported below were obtained mainly at the end of 1968 and during 1969 on archaeologic and geologic samples. Techniques of measurement used are unchanged. Since 1968, 4 complete routine sets have been running, each equipped with a 1 L CO2 proportional counter. One is made of stainless steel with a background of 2.70 cpm at pressure 1 atm and the others are of OFHC copper with a background of either 1.10 or 1.30 cpm for a corresponding pressure of, respectively, 1 or 2 atm. For age calculation, 95% activity of NBS oxalic acid is used as the modern standard and the value of 5570 ± 30 years is used for the half-life of C14. Dates are expressed in years b.p. (before a.d. 1950).

scholarly journals Physical Research Laboratory Radiocarbon Date List V

Radiocarbon ◽  
1985 ◽  
Vol 27 (1) ◽  
pp. 95-110 ◽  
Author(s):  
D P Agrawal ◽  
R V Krishnamurthy ◽  
Sheela Kusumgar
Keyword(s):  
Standard Deviation ◽  
Oxalic Acid ◽  
Research Laboratory ◽  
Radiocarbon Date ◽  
Physical Research Laboratory ◽  
Physical Research ◽  
Geologic Samples ◽  
Standard Deviations ◽  
Counting Statistics ◽  
Modern Standard

We report here dates on archaeologic and geologic samples. The samples were counted as methane in gas proportional counters. The techniques used have been described earlier (R, 1971, v 13, p 442–449). Dates are expressed in years BP, taking AD 1950 as the reference year. Modern standard was NBS oxalic acid. Quoted errors are based on counting statistics alone and are equivalent to ±1 standard deviation for samples younger than 10,000 years and ± 2 standard deviations for older samples. Descriptions and references regarding the samples have been supplied by the submitters of the samples.

scholarly journals GIF Natural Radiocarbon Measurements VI

Radiocarbon ◽  
1971 ◽  
Vol 13 (2) ◽  
pp. 213-254 ◽  
Author(s):  
G. Delibrias ◽  
M. T. Guillier ◽  
J. Labeyrie
Keyword(s):  
Oxalic Acid ◽  
Sea Level ◽  
Half Life ◽  
Level Variation ◽  
International Convention ◽  
Sea Level Variation ◽  
Geologic Samples ◽  
And Sea Level

This list consists mainly of dates obtained from analysis during 1967 and 1968 of archaeologic and geologic samples. The last section deals essentially with climatic, palynologic, and sea level variation problems. All measurements of atmospheric CO2 made periodically from 1962 until end of 1970 are also published here. In agreement with international convention, all dates have been calculated on the basis of the C14 half-life of 5568 years and 95% of NBS oxalic acid as the modern reference year.

scholarly journals University of Miami Radiocarbon Dates XI

Radiocarbon ◽  
1978 ◽  
Vol 20 (1) ◽  
pp. 134-138 ◽  
Author(s):  
D Piepgras ◽  
M M Calvert ◽  
J J Stipp
Keyword(s):  
Standard Deviation ◽  
Half Life ◽  
Radiocarbon Dates ◽  
Unknown Sample ◽  
Partial List ◽  
Geologic Samples ◽  
University Of Miami ◽  
Modern Standard

The following dates are a partial list of geologic samples dated since December 1976. The method used is described by (Stipp et al, 1976). Ages were calculated using a half-life of 5568 years. Errors reported are one standard deviation and include only the counting errors on the unknown sample, background and modern standard. There have been no corrections made on these dates. Sample descriptions and comments were written, based on information supplied by the submitters.

scholarly journals Teledyne Isotopes Radiocarbon Measurements XII

Radiocarbon ◽  
1981 ◽  
Vol 23 (3) ◽  
pp. 329-344 ◽  
Author(s):  
James Buckley ◽  
Cynthia Valdes-Pages
Keyword(s):  
Standard Deviation ◽  
Oxalic Acid ◽  
Half Life ◽  
Counting Statistics ◽  
Modern Standard

This date list reports samples completed before 1979. Methods, equipment, and techniques were reported previously (R, 1968, v 10, p 246; R, 1970, v 12, p 87). Age calculations are based on the conventional 14C half-life of 5568 years. The working laboratory standard is 95% of the NBS oxalic acid standard (SRM 4990). Results are reported in years before 1950 and the standard deviation is based on counting statistics of sample, background, and modern standard. Corrections for δ13C are not included.

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