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 Riken Natural Radiocarbon Measurements IV

Radiocarbon ◽  
1968 ◽  
Vol 10 (2) ◽  
pp. 333-345 ◽  
Author(s):  
Fumio Yamasaki ◽  
Tatsuji Hamada ◽  
Chikako Fujiyama
Keyword(s):  
Stainless Steel ◽  
Oxalic Acid ◽  
Fresh Water ◽  
Half Life ◽  
Water Shell ◽  
Calcareous Deposits ◽  
Modern Standard

The C14 dates given below are a continuation of the work presented in our previous list (RIKEN III), and have been obtained by counting CO2 at ca. 2 atm pressure in a 2.7 L stainless steel counter. Results obtained mainly during 1967 are described.Shell samples were treated with 1% HCl to remove the outer 10%. Calcareous deposits on the surface, when observed, were removed by mechanical means.Dates were calculated on the basis of the C14 half-life of 5568 yr and 95% NBS oxalic acid as modern standard. No correction was applied even for fresh water shell samples.

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 Gif Natural Radiocarbon Measurements X

Radiocarbon ◽  
1986 ◽  
Vol 28 (1) ◽  
pp. 9-68 ◽  
Author(s):  
Georgette Delibrias ◽  
M-T Guillier ◽  
Jacques Labeyrie
Keyword(s):  
Oxalic Acid ◽  
Standard Error ◽  
Proportional Counter ◽  
Half Life ◽  
Correction Curve ◽  
Geologic Samples ◽  
Made In

The following date list includes archaeologic and geologic samples dated by Gif Radiocarbon Laboratory mostly from 1973 to 1975. Volcanic samples reported here were dated up to 1981. Measurements were made in the same manner as previously reported (R, 1972, v 14, p 280). For undersized samples, a 0.1L CO2proportional counter was used with 5000-minute standard measurements. Ages listed are conventional14C ages based on the 5568-year Libby half-life; uncertainties are 1σ statistical standard error. Results are based on 95% of NBS oxalic acid activity. Some dates have been calibrated using the correction curve of Kleinet al(1982).

scholarly journals Louvain Natural Radiocarbon Measurements IV

Radiocarbon ◽  
1966 ◽  
Vol 8 ◽  
pp. 248-255 ◽  
Author(s):  
E. Gilot ◽  
N. Ancion ◽  
P. C. Capron
Keyword(s):  
Oxalic Acid ◽  
Tree Rings ◽  
Proportional Counter ◽  
Half Life ◽  
Experimental Error ◽  
The One ◽  
Contemporary Standard ◽  
Modern Standard

The following list covers most of the samples measured at the Louvain C14 laboratory since the last list (Louvain III).The method is essentially the same as the one used for the work described in the previous lists. A CH4 proportional counter, 0.6 L volume, operating at 3 atm pressure, is used. Equipment and counting techniques have been described in Louvain I. Dates are computed on the basis of the Libby half-life, 5570 yr, and the zero of the age scale is A.D. 1950. Ages are quoted with 1σ experimental error, which includes the counting variations of the sample as well as that of the background and the contemporary standard. As modern standard we now use NBS oxalic-acid standard or wood taken from A.D. 1870 to A.D. 1900 tree rings. No differences between the two standards have been observed.

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 Riken Natural Radiocarbon Measurements VIII

Radiocarbon ◽  
1974 ◽  
Vol 16 (3) ◽  
pp. 331-357 ◽  
Author(s):  
Fumio Yamasaki ◽  
Chikako Hamada ◽  
Tatsu Ji Hamada
Keyword(s):  
Stainless Steel ◽  
Oxalic Acid ◽  
Half Life ◽  
Background Counting ◽  
Modern Standard

The 14C dates given below are continued from our previous list (R, 1972, v 14, p 223–238), and results obtained mainly during 1971–2 are described. A 2.7L stainless steel counter and a 3.3L copper counter are used as previously, yielding background counting rates of 6.9 and 6.0 cpm, respectively, when filled with dead CO2 at ca 1.8 atm. Dates have been calculated on the basis of the 14C half-life of 5568 yr and 95% of NBS oxalic acid is modern standard. No correction has been made for any of the samples in this list.

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 Riken Natural Radiocarbon Measurements V

Radiocarbon ◽  
1969 ◽  
Vol 11 (2) ◽  
pp. 451-462 ◽  
Author(s):  
Fumio Yamasaki ◽  
Tatsuji Hamada ◽  
Chikako Hamada
Keyword(s):  
Stainless Steel ◽  
Oxalic Acid ◽  
Half Life ◽  
Modern Standard

The C14 dates given below are a continuation of the work presented in our previous list (Radiocarbon, 1968, v. 10, p. 333-345), and have been obtained by counting CO2 at ca. 2 atm pressure in a 2.7 L stainless steel counter. Results obtained mainly during 1968 are described.Dates have been calculated on the basis of the C14 half-life of 5568 yr and 95% of NBS oxalic acid as modern standard.

scholarly journals University of Tokyo Radiocarbon Measurements III

Radiocarbon ◽  
1971 ◽  
Vol 13 (1) ◽  
pp. 94-96 ◽  
Author(s):  
Jun Sato ◽  
Tomoko Sato ◽  
Yasuko Matsui ◽  
Hisashi Suzuki
Keyword(s):  
Oxalic Acid ◽  
Proportional Counter ◽  
Half Life ◽  
Counting Rate ◽  
Modern Standard

Radiocarbon measurements in this list were made from Sept. to Dec., 1968. They are based on acetylene counting in an Oeschger-Houtermans-type proportional counter (1 L) at pressure 1 atm. All data are based on duplicated measurements. For calculation of ages, 95% activity of NBS oxalic acid is used as the modern standard and value of 5570 + 30 years is used for the half-life of C14. Dates are expressed in years B.P. (before A.D. 1950). Error corresponds to 1σ deviation of sample net counting rate as well as modern standard and background. Details of procedures are given in previous reports (R., 1968, v. 10, p. 144–148; 1969, v. 11, p. 509–514)

scholarly journals University of Tokyo Radiocarbon Measurements II

Radiocarbon ◽  
1969 ◽  
Vol 11 (2) ◽  
pp. 509-514 ◽  
Author(s):  
Jun Sato ◽  
Tomoko Sato ◽  
Yasuko Otomori ◽  
Hisashi Suzuki
Keyword(s):  
Oxalic Acid ◽  
Proportional Counter ◽  
Half Life ◽  
Measuring System ◽  
Modern Standard

Radiocarbon measurements in the list below were made during the period from Sept. 1967 to Aug. 1968. Our measuring system is based on acetylene counting in an Oeschger-Houtermans-type proportional counter (1 L) at a pressure of I atm. All data are based on duplicated measurements. For calculation of ages, 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. Details of procedures are given in the previous report (Radiocarbon, 1968, v. 10, p. 144-148).

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