bluuebunny/crossref_metadata_2025 huggingface dataset:
Berlin Radiocarbon Measurements II
Authors: Kohl G. , Quitta H.
Published: July 2016

This date list covers age measurements carried out at the Radiocarbon Dating Laboratory of the German Academy of Sciences of Berlin (DAW) since 1963 and is a continuation of our first date list (Berlin I). Procedures and methods of preparing the samples are essentially the same. We completed our laboratory with a second electronic counting apparatus. Two further proportional counters with internal anticoincidence (Houtermann-Oeschger counters) are made from an old railway-car axle. The total volume of these counters is 4 L, the effective volume 2.2 L, the background 2.0 counts/min at 700 Torr (acetylene filling), and the contemporary standard value (0.95 NBS oxalic acid) is 20 counts/min. Each sample is measured twice, first for 48 hr and after 8 days for another 24 hr. Data have been calculated on the basis of a C14 half-life of 5570 yr (Godwin, 1962). Errors listed include the standard deviations (1σ) of the counting rates of the contemporary samples, the background and the unknown samples. Calculated errors less than 100 yr have been increased to that figure as a minimum.

Corrections have not been made for C13 content. Mass spectrometrics C13 measurements of some samples indicate that errors resulting from fractionation are minimal.
Copenhagen Radiocarbon Dates VII
Authors: Tauber Henrik
Published: July 2016

The following list comprises a selected number of measurements made up to November, 1965. Age calculations are based on a contemporary value equal to 95% of the activity of the NBS oxalic-acid standard, and on a half life for C14of 5570 yr. Results are reported in years before 1950, and in the A.D./B.C. scale. Errors quoted include the standard deviations of the count rates for the unknown sample, the contemporary value, and the background. Because possible errors arising from isotopic fractionation in the plants, or from the de Vries effect, have not been included, calculated errors smaller than 100 yr have been increased by rounding to that figure as a minimum.
University of Kiel Radiocarbon Measurements I
Authors: Willkomm H. , Erlenkeuser H.
Published: July 2016

The C14 Laboratory at Kiel University was established in 1963. It continues measurements, which were made at the Institut für Kernphysik, Kiel, on age determination with Chlorine 36, which is produced by cosmic ray neutrons (Bagge and Willkomm, 1963, 1966). The first C14-counting apparatus was completed in 1964 and dating work started at the end of 1964 after extensive general tests of counter working conditions (Erlenkeuser, 1965). The data reported here have been obtained during the first half of 1965. During this period the dating measurements were interrupted on numerous occasions by measurements of background and the oxalic standard in order to check long-time variations of the apparatus.
Arizona Radiocarbon Dates VII
Authors: Haynes C. Vance , Grey Donald C. , Damon Paul E. , Bennett Richmond
Published: July 2016

The C14 measurements reported here were made in this laboratory between November 15, 1965 and June 15, 1966. Sample descriptions are classified as follows:

I.

Geochemical Samples

II.

Geologic-Paleoclimatic Samples

III.

Early Man-Alluvial Stratigraphy Samples

IV.

Archaeologic Samples
La Jolla Natural Radiocarbon Meaurements V
Authors: Hubbs Carl L. , Bien George S.
Published: July 2016

In all measurements reported in La Jolla I through IV and for the first of those herein reported (LJ-994 to LJ-1025 and LJ-GAP-1 to LJGAP-15), we followed the procedure designed by Suess (1954) in producing acetylene (C2H2) for radiocarbon counting. For the subsequent samples, however, the following reaction for C2H2synthesis was used:
Ohio Wesleyan University Natural Radiocarbon Measurements III
Authors: Ogden J. Gordon , Hay Ruth J.
Published: July 2016

The following list of dates is compiled from samples prepared since publication of our last date list (OWU II) and includes determinations through November, 1966. Equipment and operating procedures are the same, except that the sample conversion system has been altered to include a second vacuum pumping system and a separate oxygen/nitrogen combustion train.
Uppsala Natural Radiocarbon Measurements VII
Authors: Olsson Ingrid U. , Stenberg Allan , Göksu Yeter
Published: July 2016

The following list covers some old measurements not included in previous lists and most of the samples measured at the Uppsala C14 laboratory since the last list (Uppsala V) except for all of the samples utilized for determining the increase of the C14/G12 ratio due to explosion of nuclear devices, and except for more than twenty samples measured for testing, storing, and pretreatment of Foraminifera
Institute of Geological Sciences Radiocarbon Dates I
Authors: Welin E. , Engstrand L. , Vaczy S.
Published: July 2016

This date list was compiled by the Institute of Geological Sciences (U.K.) incorporating data supplied under contract by Dr. E. Welin, Radioactive Dating Laboratory, Stockholm. Unless otherwise stated age figures are in C14 years before A.D. 1950. The half-life of C14 is taken as 5568 years and the standard error is given as a standard deviation of 1σ. Correction for C13/C12 has not been made. This is the first of a series of annotated lists of C14 dates of British and overseas material in course of preparation by the Institute.
Tartu Radiocarbon Dates V
Authors: Punning J. M. , Ilves E. , Liiva A. , Rinne T.
Published: July 2016

The following list includes samples dated in 1968 and 1969. Wood dating from A.D. 1850 ± 10 yr is used as contemporary reference standard. Background sample is synthesized from anthracite or shungite. All radiocarbon dates were calculated with C14 half-life of 5568 ± 30 yr. All dates are calculated from the year 1950.
Tata Institute Radiocarbon Date List VIII
Authors: Agrawal D. P. , Gupta S. K. , Kusumgar Sheela
Published: July 2016

Given below are the dates of archaeologic and Quaternary samples measured by the proportional counting of methane gas. Details of the techniques used were published earlier (Agrawal et al., 1965).
Belfast Radiocarbon Dates III
Authors: Smith A. G. , Pearson G. W. , Pilcher J. R.
Published: July 2016

The dating equipment in the Palaeoecology Laboratory remains essentially as described in R., 1970, v. 12, p. 285–290, and the operating conditions as described in R., 1970, v. 12, p. 291–297. Small samples, however, have been counted at a filling pressure equivalent to 152 cm Hg at 20°C. Charcoal samples pretreated by nitration have been treated as described in R., 1970, v. 12, p. 285–290. Other charcoal samples have been pretreated using the following technique developed by P. Q. Dresser: samples are washed in 5% sodium hydroxide; this is followed by treatment in a solution composed of 8% potassium permanganate and 10% sulphuric acid, at 80°C for 20 mins, to remove residual rootlets and organic matter. Unless specifically stated, the samples have been collected by the authors and other members of the Laboratory: M. G. L. Baillie, P. Q. Dresser, Adelaide Goddard, and I. Goddard. Where a sample has been collected for a specific research project the collector's initials are given. Routine operation of the dating apparatus has been carried out by Mrs. Marilyn Carse and Mrs. Florence Qua to whom we are much indebted.
Uppsala Natural Radiocarbon Measurements XI
Authors: Olsson Ingrid U. , Klasson Martin , Abd-El-Mageed Abdalla
Published: July 2016

The following list covers some old measurements not included in previous lists and most of the samples measured at the Uppsala C14 laboratory since the last list (R., 1969, v. 11, p. 515–544); samples utilized for determining the increase of the C14/C12 ratio due to explosion of nuclear devices are omitted.
Monaco Radiocarbon Measurements IV
Authors: Thommeret J. , Thommeret Y.
Published: July 2016

The following list of dates includes most of the samples processed from 1968 to 1972. Proportional counting is used and the counting gas is CO2at constant filling pressure of 740mmHg at 22°C (Thommeretet al., 1969). Samples are counted at least twice on two different counters and errors quoted are averages of standard deviations obtained on each counting.
Vienna Radium Institute Radiocarbon Dates IV
Authors: Felber Heinz , Pak Edwin
Published: July 2016

Measurements have continued with the same proportional counter system, the same procedure in sample pretreatment, methane preparation and measurement, and the same age calculation using a half-life of 5568 ± 30 yr as described previously (R., 1970, v. 12, p. 298–318).
Dublin Radiocarbon Dates II
Authors: Dresser P Q , Mcaulay I R
Published: July 2016

The Dublin radiocarbon dating laboratory was operational in 1958 to 1960 and the scintillation counter system used at that time has previously been described (Delaney and McAulay, 1959). The system is now operational again and has been modified to date samples after conversion to benzene. The electronic equipment differs from that previously used only insofar as more compact and drift-free transistorized units are now employed. With these modifications, considerable improvements in sensitivity and accuracy are obtained. 5ml benzene, diluted with a commercial toluene based scintillant is used in a 12.5ml silica cell for the detection of 14C disintegrations. The background count-rate varies inversely with the barometric pressure (ca 2.6% cm–1Hg). The background is ca 3.4cpm, and the detection efficiency is ca 60% and excludes the tritium spectrum.
Kaeri Radiocarbon Measurements III
Authors: Pak Chan Kirl , Yang Kyung Rin
Published: July 2016

14C dates listed in this report on geochemical, geologic, and archaeologic samples were obtained mainly from the beginning of 1971 to the middle of 1973. Techniques of measurement used are the same as described previously (Yang, 1972). Sample descriptions and comments for archaeologic samples were prepared in collaboration with collectors and submitters. For age calculation, 95% activity of NBS oxalic acid is used as the modern standard and the value of 5568 ± 40 years is used for the half-life of 14C. Dates are expressed in years bp (before ad 1950). The error (1σ) quoted is calculated from the uncertainty involved in counting background, NBS oxalic acid standard, and sample.
Physical Research Laboratory Radiocarbon Date List I
Authors: Agrawal D P , Krishnamurthy R V , Kusumgar Sheela , Pant R K
Published: July 2016

As the Radiocarbon Lab of the Tata Institute, Bombay, has now been shifted to the Physical Research Laboratory (PRL), Ahmedabad, our new date lists will be termed as above and the samples will be given PRL numbers instead of the former TF. All the pending TF samples were given new PRL numbers.
Tallinn Radiocarbon Dates III
Authors: Punning J M , Kakum T , Rajamäe R
Published: July 2016

This list comprises age measurements carried out from 1973 to 1974 In dating the samples reported here as well as in calculating their ages, the same equipment and methods were used as previously described (R, 19/3, v 15, p 586–591; 1974, v 16, p 388–394).
University of Washington Dates IV
Authors: Fairhall A W , Young A W , Erickson J L
Published: July 2016

The dates reported in this list are for geologic and archaeologic samples only. During the interval since our last date list (R, 1966, v 8, p 498-506) most of our measurements have been on samples of sea water. These will be reported separately at a later time. The methods used are essentially those reported previously (R, 1963, v 5, p 80-81) but with the following notable changes and additions: We now prepare our methane counting gas as described in Buddemeier et al (1970). Our IL membrane counter has since been augmented by 3 additional counters. Two of these are IL quartz proportional counters inside geiger anticoincidence shields. Operating pressures are ca 1.5 to 4atm. Backgrounds of these 2 counters are in the neighborhood of 1.8 and 3cpm and the net counting rate of NBS oxalic acid ranges from 7 to 18.7cpm, depending on the pressure. The third counter (“minicounter”) is rather special: .IL quartz proportional counter inside a methane proportional anticoincidence counter. Sample and anticoincidence counting gases are introduced simultaneously with a differential pressure that never exceeds a few cm Hg. The sample filling side is constructed so as to minimize dead volume; over 80% of the sample gas is inside the active volume of the 14C counter. The range of filling pressures which are possible is ca 1 to 4atm.
University of Rome Carbon-14 Dates XIV
Authors: Alessio M , Bella F , Improta S , Belluomini G , Calderoni G , Cortesi C , Turi B
Published: July 2016

This list includes dates measured from January 1974 to June 1975 with previously described CO2proportional counters (Alessioet al, 1970b). All archaeologic and geologic samples except for Arslantepe series come from Italian territory. Chemical apparatus for CO2preparation and purification is unchanged (Alessioet al, 1970b). Data recording devices have recently been replaced with integrated circuits built entirely at the Lab. The logic of the circuitry was also modified to provide more stable devices and a higher relative figure of merit A/√B of each counter (A = net activity of modern standard, B = background). Consequently, the resolution of age measurements has increased appreciably. Present values of A/√B for the 4 counters in use are shown in Table 1.
University of Miami Radiocarbon Dates VII
Authors: Stipp J J , Eldridge K L , Valenziano K
Published: July 2016

The following radiocarbon measurements are a partial list of geologic samples from S Florida dated during the summer of 1975. The technique used is liquid scintillation counting of wholly synthesized benzene as indicated in R, v 16, p 402-408 and 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. Before conversion, shell material was etched with HCl to remove all soft or powdery material. All wood and peat samples were treated with NaOH.
La Jolla Natural Radiocarbon Measurements VII
Authors: Linick T W
Published: July 2016

Radiocarbon dating of many types of samples has continued at the La Jolla Radiocarbon Laboratory since the last date list was published (Bien and Pandolfi, 1972). Since the 1969 relocation of the laboratory to its present location on Mt Soledad, at least 5 low-level14C systems have generally been in operation. The laboratory has continued to employ acetylene gas proportional counting. Samples were usually measured for 2 to 3 days in each of 2 different detectors. The properties of the 5 counters used in the measurements of samples are as follows (background and net standard counts per minute, respectively, with acetylene of 900mmHg pressure are given in parentheses): 1) Bern counter: Oeschger-type counter-guard ring unit with 1.7L sensitive center volume (2.1, 21.5), 2) MBLE counter: Oeschger-type counter-guard ring unit with 1.6L center volume (1.3, 17.4), 3) 1L counter with separate Q-gas flow guard ring (4.2, 12.9), 4) 0.4L counter with separate guard ring (1.2, 4.2), and 0.1L counter with separate guard ring (0.7, 1.2).
Radiocarbon, Ltd Natural Radiocarbon Measurements II
Authors: Tucek Charles S
Published: July 2016

Radiocarbon, Ltd moved its laboratory facilities from Spring Valley, New York to Lampasas, Texas in the summer of 1974. This date list represents all results obtained at the Spring Valley location for which sample data have been received, and which have not been reported previously.
Discussion Reporting of 14C Data
Authors: Stuiver Minze , Polach Henry A
Published: July 2016

Count rates, representing the rate of 14C decay, are the basic data obtained in a 14C laboratory. The conversion of this information into an age or geochemical parameters appears a simple matter at first. However, the path between counting and suitable 14C data reporting (table 1) causes headaches to many. Minor deflections in pathway, depending on personal interpretations, are possible and give end results that are not always useful for inter-laboratory comparisons. This discussion is an attempt to identify some of these problems and to recommend certain procedures by which reporting ambiguities can be avoided.
Rudjer BošKović Institute Radiocarbon Measurements IV
Authors: Srdoč Dušan , Sliepčevic Adela , Obelic Bogomil , Horvatinčic Nada
Published: July 2016

The following list contains dates of samples measured since our previous list (R, 1975, v 17, p 149-155). As before, age calculations are based on the Libby half-life 5570 ± 30 yr and reported in years before 1950. The modern standard is 0.950 of the activity of NBS oxalic acid.
University of Rome Carbon-14 Dates XV
Authors: Alessio M , Allegri L , Bella F , Improta S , Belluomini G , Calderoni C , Cortesi C , Manfra L , Petrone V , Fruscalzo A
Published: July 2016

This list includes ages measured from August 1974 to May 1976 using the benzene scintillation method. All archaeologic and geologic samples except Sahara Libico series, come from Italian territory. These datings were carried out partly with the liquid scintillation counter previously described (Alessio et al, 1973) and partly with a new liquid scintillation counter (Alessio et al, 1976b). Vials, 4.5ml in volume, described in Alessio et al, 1973. Mixture consists of 3.5ml of benzene from sample and 1ml of commercial liquid scintillator NE 216. The characteristics of new counter are: background 2.90 cpm and figure of merit
University of Texas at Austin Radiocarbon Dates XII
Authors: Valastro S , Davis E Mott , Varela Alejandra G
Published: July 2016

This list reports certain 14C measurements completed by November 1977; other projects completed by this time will be reported later. Age calculations are based on 14C half-life of 5568yr and modern standard of 95% NBS oxalic acid, supplemented by tree rings of pre-industrial wood from a log cut in the 1850's (Tx-540; R, 1970, v 12, p 249). Deviations reported are based on counting statistics of sample, background, and modern, and are ±1σ, except that when sample count approaches either modern or background, 2σ limits are reported. Unless noted, 12C/13C measurements were not made and results are not corrected for 13C fractionation. Our laboratory uses liquid scintillation counting of benzene, with Li2C2 and vanadium-activated catalyst in preparation; chemical yields range between 95% and 99%. Three counters are employed: a Packard Tri-Carb Model 3002 and 2 Beckman LS320 spectrometers obtained through a grant from the National Science Foundation.
Belfast Radiocarbon Dates IX
Authors: Pearson G W
Published: July 2016

The dating equipment and operating conditions remain essentially as described in R, 1970, v 12, p 285-286, except that the samples are now measured at either 76, 152 or 380cm Hg at 20°C to allow for the variation in sample size. The calculation of results and correction for isotopic enrichment remain as previously described in R, 1973, v 15, p 212.
British Museum Natural Radiocarbon Measurements XI
Authors: Burleigh Richard , Hewson Andrew
Published: July 2016

The following list consists of dates for archaeologic samples measured over the period from June 1974 to July 1976. The dates were obtained by liquid scintillation counting of benzene using a Model 3315 Packard Tricarb Liquid Scintillation Spectrometer linked to a Hewlett Packard 2100A computer system for on-line processing of counting data (Hall & Hewson, 1977). The laboratory procedures used were essentially those outlined in previous lists (see, eg, BM-VIII, R, 1976, v 18, p 16).
Nancy Natural Radiocarbon Measurements V
Authors: Coppens R , Guillet B , Jaegy R , Richard P
Published: July 2016

The following list includes some measurements made during 1975-1978 since our last list (R, 1978, v 20, p 62-67) in the National Radiocarbon Laboratory of the Ecole Nationale Supérieure de Géologie Appliquée et de Prospection Minière (ENSG) de Nancy.
Tartu Radiocarbon Dates IX
Authors: Liiva A , Elina G , Tchatchkhiani V , Rinne T
Published: July 2016

The following list contains dates of organogenous sediments (peat and sapropel from the Karelian ASSR) made in 1972 to 1977 with the aim of studying the history of the development of peat bogs in the Holocene (Elina, 1969; 1971a,b; Pyavchenko et al, 1976). Samples were collected with Hiller or Instorf samplers. Borings were made in the deepest parts of the peat bogs.
UCLA Radiocarbon Dates X
Authors: Berger Rainer , Ericson Jonathon
Published: July 2016

The measurements reported in this date list form the chronometric framework for obsidian hydration and trade studies in California (Ericson, 1975; 1977; 1978; 1981; Ericson et al, 1975; Singer and Ericson, 1977). All samples were analyzed as CO2 gas at close to 1 atm in a 7.5L proportional counter with three energy channels. Radiocarbon ages are based by convention on the 5568 ± 30 yr half-life. The biospheric standard is 95% the count rate of NBS oxalic acid for radiocarbon laboratories. Background is based on CO2 obtained from marble. Counter operation is checked against a historically dated wood sample from the funerary boat of Sesostris III, 1872 +4−8 BC (Hayes, 1962). All samples were subjected to accepted NaOH, HCl or other special chemical treatments to exclude contamination. No tree-ring calibration was applied to any of the samples listed.
Dendrochronology at Belfast as a Background to High-Precision Calibration
Authors: Baillie M G L , Pilcher J R , Pearson G W
Published: July 2016

The tree-ring program at Belfast originally aimed at the construction of a 6000-year oak chronology. The stimulus for this work came from the large numbers of sub-fossil oaks uncovered in Northern Ireland during land drainage and motorway construction in the late 1960's (Pilcher et al 1977). It became clear that any attempt to build such a long chronology would break naturally into two distinct units. One unit related to the construction of a prehistoric (BC era) chronology dependent on the sampling of large numbers of essentially random sub-fossil timbers. For this unit to be successful, timbers would have to survive relatively uniformly through time. The second chronology building unit was related principally to the AD era, with a natural extension into the first millennium BC at least. This unit was envisaged as the link between the present day and the necessarily floating sub-fossil chronologies. This AD chronology was based on modern, historic, and archaeologic timbers.
High-Precision 14C Measurement of Irish Oaks to Show the Natural Atmospheric 14C Variations of the AD Time Period
Authors: Pearson G W , Baillie M G L
Published: July 2016

The high-precision 14C measurement of bi-decade and decade samples of Irish Oak for the time period AD 50 to 1830 is presented. The samples were taken from dendrochronologically dated Irish Oak providing an absolute chronology for this period. While the natural atmospheric 14C concentration shows cyclic deviations from a constant value, the amplitudes of such deviations vary considerably. Repeated measurement and interlaboratory checks justify a claim to accuracy in the data given. Comparison of a large number of data sets between Belfast and Seattle show that the different techniques of scintillation counting of 14C6H6 and gas counting of 14CO2 derived from different wood species grown in different continents give no significant bias. Thus, it is justifiable to use this data set as a high-precision calibration curve for the AD period. Over most of this period bi-decade samples were measured giving a slightly reduced resolution of short-term variation when compared to the measurement of decade intervals; however, any difference is not apparent when such curves are compared. It is of much greater importance that a comparison of data sets is without bias if a combined calibration curve is to have sufficient integrity for general use. Averaging the data from Belfast and Seattle would improve the validity of such an AD 14C calibration curve since it would tend to smooth out slight local variations and become internationally more acceptable.
Dendrochronology of Bristlecone Pine: A Progress Report
Authors: Ferguson C W , Graybill D A
Published: July 2016

Dendrochronological studies of bristlecone pine, Pinus longaeva, have produced a continuous tree-ring sequence back to 6700 BC for the White Mountains of California and to 3258 BC for east-central Nevada.
Mathematical Modeling of the Distribution of Natural 14C, 234U, and 238U in a Regional Ground-Water System
Authors: Pearson F J , Noronha C J , Andrews R W
Published: July 2016

Increasing concern with nuclear waste isolation technology is leading to additional studies of naturally occurring isotopes in ground water. Such studies provide information on 1) the use of radionuclides to estimate ground-water travel times and/or residence times. This information can he an extremely useful adjunct to conventional hydrologic data in developing the understanding of regional hydrology needed in the site selection process, and 2) the use of natural radionuclides as analogues to the behavior of radionuclides of concern in nuclear waste.
Distribution of Gaseous 12CO2, 13CO2, and 14CO2 in the Sub-Soil Unsaturated Zone of the Western US Great Plains
Authors: Thorstenson D C , Weeks E P , Haas Herbert , Fisher D W
Published: July 2016

Data on the depth distribution of the major atmospheric gases and the abundance of gaseous 12CO2, 13CO2, and 14CO2 in the subsoil unsaturated zone have been obtained from several sites in the western Great Plains of the United States. Sample profiles range from land surface to depths of 50m. Although each site must be considered on an individual basis, several general statements can be made regarding the profiles. 1) Diffusion of these gaseous molecules through the unsaturated zone is an important transport mechanism. 2) As predicted by diffusion theory, depth profiles of the various isotopic species of CO2 differ substantially from one another, depending on individual sources and sinks such as root respiration and oxidation of organic carbon at depth. 3) In general, post-bomb (> 100% modern) 14C activities are not observed in the deep unsaturated zone, in contrast to diffusion model predictions. 4) In spite of generally decreasing 14C activities with depth, absolute partial pressures of 14CO2 in the subsoil unsaturated zone are 1–2 orders of magnitude higher than the partial pressure of 14CO2 in the atmosphere.
Possible Depletion in 14C in Trees Growing in Calcareous Soils
Authors: Tauber Henrik
Published: July 2016

14C activities of decadal samples from beech trees growing under extreme calcareous conditions were compared to 14C activities of decadal samples of the same age from a beech tree growing in a normal mold soil in order to see whether part of the carbon assimilated during photosynthesis might originate from 14C-deficient carbonates in the soil. The calcareous soils contained from 18 to 52% calcium carbonate, and this carbonate had a mean 14C age of 10,200 to 17,600 years BP. A comparison was also made with the 14C activity of contemporaneous samples from Douglas Fir from the US North Pacific (Stuiver, 1982).

No significant depletion in 14C activity in beech trees growing in the highly calcareous soils was detected. The measured mean difference in 14C activity in beech trees from calcareous and non-calcareous sites corresponds to an uptake of 0.12 ± 0.3% carbon from soil carbonates in the calcareous sites.
Radiocarbon Dating of Fossil Eggshell
Authors: Long Austin , Hendershott R B , Martin P S
Published: July 2016

Controlled feeding experiments demonstrate that the 14C content of the carbonate fraction of fossil avian eggshell should reliably reflect the 14C activity of feed and contemporary atmospheric CO2 regardless of amounts of 14C depleted scratch injested. Consideration of biochemical pathways and exchange rates across lung membranes leads to the possibility that the carbonate fraction may, in some instances, be slightly 14C depleted. 14C dates on eggshell carbonate should require little or no correction. As with marine shell carbonate, normal soil-forming processes may alter the surficial carbon isotopes in eggshell carbonate. 14C dates on the protein fraction should be even more reliable than those on the carbonate fraction, but only if special precautions or separation techniques exclude non-indigenous carbon from the sample. Original protein contents are likely to be too low for conventional 14C dating techniques.
Anthropogenic 14C Variations
Authors: Segl Monika , Levin Ingeborg , Schoch-Fischer Hilla , Münnich Marianne , Kromer Bernd , Tschiersch Jochen , Münnich Karl Otto
Published: July 2016

Continuous 14C data of 1 or 2 weekly samples of atmospheric CO2 are presented, collected near two nuclear power plants (NPP-Biblis and NPP-Philippsburg) located in the rather densely populated upper Rhine valley. Tree-leaf and tree-ring samples from the area of a boiling water reactor in northern Germany (NPP-Würgassen) are also presented and discussed. Additional atmospheric 14CO2 samples from two continental ‘clean-air’ stations in Germany and Austria were used as reference for the polluted areas. For January 1982, these samples yield a ‘clean-air’ 14C concentration in central Europe of Δ14C=255±5‰ (7.7pCi/gC = 1.45pCi/m3 air).
The Use of 14C in Natural Materials to Establish the Average Gaseous Dispersion Patterns of Releases from Nuclear Installations
Authors: Otlet R L , Walker A J , Longley H
Published: July 2016

The Harwell Low Level measurements Laboratory has been measuring a variety of natural materials from locations close to United Kingdom nuclear installations since 1977. The measurements are made first, to establish the past effects of releases to the atmosphere of 14C as observed from individual tree rings and second, to establish dispersion contours averaged over extended periods. The main study area has been in Cumbria, around the BNFL nuclear installation at Sellafield. 14C, which can be measured to good precision even at values close to the normal natural levels, provides a powerful technique for the provision of practical experimental values much wanted for theoretical dispersion models.
On the Origin of Carbonaceous Particles in American Cities: Results of Radiocarbon “Dating” and Chemical Characterization
Authors: Currie L A , Klouda G A , Continetti R E , Kaplan I R , Wong W W , Dzubay T G , Stevens R K
Published: July 2016

During the past three years radiocarbon assay has emerged as a primary tool in the quantitative assignment of sources of urban and rural particulate pollution. Its use in several major field studies has come about because of its excellent (fossil/biogenic) discriminating power, because of advances in 14C measurements of small samples, and because of the increased significance of carbonaceous particles in the atmosphere. The problem is especially important in the cities, where increased concentrations of fine particles lead to pollution episodes characterized by poor visibility and changes in the radiation balance (absorption, scattering), and immediate and possibly long-term health effects. Efforts in source apportionment in such affected areas have been based on emissions inventories, dispersion modeling, and receptor modeling – ie, chemical and physical (and statistical) characterization of particles collected at designated receptor sites. It is in the last category that 14C has become quite effective in helping to resolve particle sources. Results are presented for studies carried out in Los Angeles, Denver, and Houston which incorporated 14C measurements, inorganic and organic chemical characterization, and receptor modeling. The 14C data indicated wide ranging contributions of biogenic and fossil carbon sources – eg, <10% to 60% contemporary (biogenic) in Houston – depending on meteorological, biological, and anthropological activity. The combined (chemical, isotopic, statistical) data point to sources such as vehicles, wood combustion, power plants, and vegetation.
Radiocarbon Database: A Pilot Project
Authors: Gulliksen Steinar
Published: July 2016

Computer storage and surveys of large sets of data should be an attractive technique for users of14C dates. Our pilot project demonstrates the effectiveness of a text retrieval system, NOVA STATUS. A small database comprising ca 100 dates, selected from results of the Trondheim14C laboratory, is generated. Data entry to the computer is made by feeding typewritten forms through a document reader capable of optical character recognition. A text retrieval system allows data input to be in a flexible format. Program systems for text retrieval are in common use and easily implemented for a14C database.
Accelerator Mass Spectrometry: From Nuclear Physics to Dating
Authors: Kutschera Walter
Published: July 2016

One of my former teachers in nuclear physics, H Morinaga, once pointed out to me that essentially all the fundamental discoveries in nuclear physics were done without the use of accelerators. At first, this statement seemed extremely exaggerated, but now I think there is much truth in it. Once we build an instrument to investigate a specific problem we have already realized the existence of the problem and do not need the instrument to discover it. It is almost inevitable that the most interesting discoveries with a new technique will be made in fields for which the technique was not invented. Accelerators, built for nuclear physics, produced a great amount of data on nuclear structure and forces but the most fundamental discoveries were made in elementary particle physics. In any case, for almost 40 years the sole purpose of accelerators was to deliver beams of ever increasing energy and versatility to perform experiments after the accelerator. The analytic properties of accelerators were almost completely ignored even after the very early use of the Lawrence cyclotron at Berkeley as a mass spectrometer to discover 3He in nature (Alvarez and Cornog, 1939 a; b). The enormous analytic power of accelerators is now fully recognized, but the joy of the revival is mixed with some disappointment that the great prospects for studying 14C problems (Muller, 1977; Bennet et al, 1977; Nelson, Korteling, and Stott, 1977) have not yet been fulfilled. Fortunately, some of the papers of this conference show that a big step forward has been taken. But in view of what I said before it is not surprising that most of the studies were actually done with other radioisotopes.
Technological Advances in the University of Washington Accelerator Mass Spectrometry System
Authors: Farwell G W , Grootes P M , Leach D D , Schmidt F H
Published: July 2016

During the past year we have continued to work toward greater stability and flexibility in nearly all elements of our accelerator mass spectrometry (AMS) system, which is based upon an FN tandem Van de Graaff accelerator, and have carried out measurements of 14C/12C and 10Be/9Be isotopic abundance ratios in natural samples. The principal recent developments and improvements in the accelerator system and in our sample preparation techniques for carbon and beryllium are discussed, and the results of a study of 10Be cross-contamination of beryllium samples in the sputter ion source are presented.
The Question of Diffuse Secondary Growth of Palm Trees
Authors: Wiesberg L H G , Linick T W
Published: July 2016

14C activity measurements were used to investigate the growth pattern of the stem of a palm tree (Cocos nucifera) which does not form annual rings. The results reveal that there was no diffuse secondary growth (thickening of the stem) over the entire mature stem during the last 25 years of growth, with the exception of a restricted zone in the center at medium height.
Carbon Isotope Analysis of Land Snail Shells: Implications for Carbon Sources and Radiocarbon Dating
Authors: Goodfriend Glenn A , Hood Darden G
Published: July 2016

13C and 14C analyses were performed on a series of modern Jamaican land snails in order to quantitatively determine the sources of shell carbon. A model of these carbon sources, the pathways by which carbon reaches the shell, and the fractionation processes involved are presented. The contribution of limestone to shell carbonate is variable but may comprise up to 33% of the shell. About 25–40% of shell carbonate is derived from plants and about 30–60% from atmospheric CO2. Variation among populations and species with respect to 13C and 14C is attributed to the effects of limestone incorporation, snail size (as it affects CO2 exchange rate), physiological characteristics (presence of urease, respiration rate), and activity patterns of the snails. A formula for correction for isotopic fractionation of 14C of shell carbonate, based on 13C measurements, is derived. Bicarbonate-aragonite fractionation is apparently very minimal. Shell organic carbon appears to be derived largely from plants but also to a lesser extent from inorganic hemolymph carbon. This introduces the possibility of a small age anomaly of shell organic 14C due to limestone incorporation.
University of Georgia Radiocarbon Dates VII
Authors: Noakes John E , Herz Norman
Published: July 2016

Radiocarbon dates reported in this date list are totally derived from a cooperative effort between the Romanian Institute of Geology and Geophysics and the Center for Applied Isotope Studies (CAIS). The project was carried out between 1972 through 1978. The purpose of the study was to add to the knowledge of the various stages of the Holocene development of the Danube and Black Sea (Ghenea et al, 1971; Panin, 1976).
Time Series Analysis of Low Level Gas Counting Data
Authors: Kaihola Lauri , Polach Henry , Kojola Hannu
Published: July 2016

We demonstrate the feasibility of pulse time of arrival information for early detection of periodic events in low level counting. Time of arrival data allows us to apply time series analysis and serial correlation tests which, in graphic form, give the user an illustrative view of the parameters affecting the validity of counting statistics. The decision to discontinue counting can already be made on the basis of less than 100 counts from the time information alone if more than 10 of these are non-Poisson periodic counts. The analyses also serve as a means of quality control for low level counting, being directly based upon the interval distribution of the Poisson process.
Frankfurt Radiocarbon Dates I
Authors: Protsch Reiner , Weninger Bernhard
Published: July 2016

Facilities for radiocarbon dating were established at the University of Frankfurt/Main in the Institute of Anthropology. The Radiocarbon Laboratory provides assistance to the Amino-Acid-Dating Laboratory. This list reports on 14C dates measured up to September 1983.

The laboratory is installed in the basement of a three-story building and is equipped with a 2L copper proportional counter filled to 1013 mbar with purified CO2. The counter is protected against cosmic and surrounding radiation by a 3.5 ton lead shield and a copper multiwire anticoincidence ring-counter flushed with purified 90Ar/10CH4. Electronics are of the commercial NIM type. Charcoal and wood samples are treated by standard acid-alkali-acid methods. Bone samples are treated according to the collagen methods described by Berger, Horney, and Libby (1964), Longin (1971), Protsch (1972; 1975), and Protsch and Berger (1973).
Hamburg University Radiocarbon Dates III
Authors: Scharpenseel H W , Schiffmann Heinrich , Hintze Bernd
Published: July 2016

The following list consists of dates of soil samples, partly produced in the former Bonn laboratory and bearing the code designations, BONN, and partly in the present dating lab at Hamburg University. The list comprises Mollisols and Inceptisols from Germany, sampled by layer and dated as whole soil, hydrolysis residue, and hydrolysate. Other profiles represent selected Australian Vertisols and Krasnozems, sampled by layer as well. Dates derived from marshes of the Elbe River as well as from paleosols buried by coastal levees are also included in the list. Pretreatment of soil samples is described in Scharpenseel and Pietig (1969) and Scharpenseel (1972; 1977).
University College Cardiff Radiocarbon Dates I
Authors: Dresser Quentin
Published: July 2016

The laboratory was established by University College, Cardiff, in 1974 primarily for research in vegetation history and archaeology in Britain. The laboratory has been supported yearly since 1978 by the Conservation and Land Division of the Welsh Office, Cardiff, which submits archaeologic samples from rescue excavations in Wales which are carried out by the Clwyd-Powys Archaeological Trust Ltd (CPAT), the Dyfed Archaeological Trust Ltd (DAT), the Glamorgan Gwent Archaeological Trust Ltd (GGAT), and the Gwynedd Archaeological Trust Ltd (GAT).
Lyon Natural Radiocarbon Measurements X
Authors: Evin Jacques , Marechal Joelle , Marien Gerard
Published: July 2016

This list includes most of the measurements made since the beginning of the compilation of our previous list (R, 1983, v 25, p 59–126), in 1982 and 1983, as well as some earlier measurements of extended geologic or archaeologic studies.
University of Wisconsin Radiocarbon Dates XXII
Authors: Steventon Raymond L , Kutzbach John E
Published: July 2016

Procedures and equipment used in the University of Wisconsin laboratory have been described in previous date lists (Steventon & Kutzbach 1983; 1984). Except as otherwise indicated, wood, charcoal, and peat samples are pretreated with dilute NaOH-Na4P2O7 and dilute H3PO4 before conversion to the counting gas methane; when noted, marls and lake cores are treated with acid only. Very calcareous materials are treated with HCl instead of H3PO4. Pretreatment of bone varies with the condition of the bone sample; solid bone with little deterioration is first cleaned manually and ultrasonically. The bone is treated with 8% HCl for 15 minutes, then dilute NaOH-Na4P2O7 for 3 hours at room temperature, washed until neutral, and the collagen extracted according to Longin (1971). Charred bone is treated with dilute HCl, NaOH-Na4P2O7, and then dilute HCl again.
Fast and Complete CO2-to-Graphite Conversion for14C Accelerator Mass Spectrometry
Authors: Hut Gert , Östlund H Göte , van der Borg Klaas
Published: July 2016

With Fe powder as a catalyst, CO2is completely converted to graphite within 90 minutes. The reaction proceeds at 650°C with an excess of H2. The reaction rate is enlarged by forced circulation and by keeping the water vapor pressure very low. The graphite samples obtained, consisting of 5mg of carbon, almost immediately produce stable12C−currents of the order of 20–30μA in the sputter source of a Van de Graaff accelerator. The currents can be maintained for at least 10 hours and are comparable to those from commercial graphite. No memory effects in the preparation system have been observed.
Precise Calendrical Dating of Known Growth-Period Samples Using a ‘Curve Fitting’ Technique
Authors: Pearson G W
Published: July 2016

Absolute high-precision radiocarbon time-scale calibration is now available and is shown by Stuiver and Pearson (1986) and Pearson and Stuiver (1986) to be internationally valid. The technique of curve fitting presented in this paper shows how certain samples may be dated calendrically to within a very narrow band width ca ± 20 years, at time periods when single sample analysis would give ambiguous calendrical conversion. Samples of known deposition rate covering a time span of >50 years are subdivided to produce a ‘floating curve’ and this curve is then ‘wiggle matched’ with the high-precision calibration to give a precise calendrical age.
Operation of the NSF-Arizona Accelerator Facility for Radioisotope Analysis and Results from Selected Collaborative Research Projects
Authors: Linick T W , Jull A J T , Toolin L J , Donahue D J
Published: July 2016

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.
Applications of the Use of Hawthorn Berries in Monitoring 14C Emissions from a UK Nuclear Establishment Over an Extended Period
Authors: Walker A J , Otlet R L , Longley Harry
Published: July 2016

The paper describes a study undertaken to examine the dispersion pattern of gaseous emissions, as indicated by 14C uptake in natural materials, around the nuclear reprocessing plant at Sellafield, Cumbria, UK. The extent and directional dispersion of the released 14C is established and its variability over an extended period assessed. Results of measurements taken during three sampling seasons (1981, 1982, 1983) of the 14C activity in hawthorn berries collected over a wide area are presented and the dispersion pattern contours constructed from them are examined. Only limited agreement of the results with the theoretical relationship 1/r is found and both meteorology and topography are seen to be important in determining the shape of the observed patterns.
The Influence of Contaminating (Fossil) Carbonate and the Variations of δ13C in Mortar Dating
Authors: Van Strydonck Mark , Dupas Michel , Dauchot-Dehon Michelle , Pachiaudi Christiane , Marechal Joelle
Published: July 2016

The influence of the aggregate in mortar dating is examined. Sample activity as well as isotopic fractionation approach the expected values at lower yields of the preparation reaction of the counting gas. Good results are obtained at low fossil carbonate concentration. δ13C cannot give information about this concentration but preliminary visual and chemical analysis of the mortar makes prediction of sample validity possible.
Early Slavonic Settlements and Navigation at the Mouth of the Odra River
Authors: Awsiuk Romuald , Filipowiak Władysław , Goslar Tomasz , Pazdur Anna , Pazdur Mieczysław F
Published: July 2016

An attempt is presented to establish an absolute chronology of early Slavonic habitation in the region of the mouth of the Odra River up to the Baltic and to find associations with a series of stave boats and dugouts of different levels of technology and navigation. The methodology of the research project is presented and some conclusions of a general nature are drawn from the results already obtained.
The Prehistoric Expansion of Farming into “Arctic” Norway: A Chronology Based on 14C Dating
Authors: Johansen Olav Sverre , Vorren Karl-Dag
Published: July 2016

Palynologic and archaeologic studies using 14C dating indicate that elements of farming were introduced even further north than the Arctic Circle during the Neolithic period, ca 4000 BP. A second stage with heavier reliance on farming and with probable establishment of permanent farmsteads is dated to 2000–2500 BP.
Berlin Radiocarbon Measurements IV
Authors: Kohl G. , Quitta H.
Published: July 2016

This list includes selected dates of archaeologic samples from DDR, Czechoslovakia, Hungary and the Soviet Union made between 1966 and 1969. As in previous lists the major portion of dates are concerned with Neolithic and Early Bronze age period in Middle and SE Europe.
Glasgow University Radiocarbon Measurements III
Authors: Baxter M. S. , Walton A.
Published: July 2016

The following list presents results obtained during 1968-69 on a series of samples chosen to investigate temporal variations of C14 concentrations in the atmosphere during the past century. Together with data presented previously (Radiocarbon, 1969, v. 11, p. 45-52) they constitute a study of annual variations of C14 activities at N temperate latitudes.
University of Lund Radiocarbon Dates III
Authors: Håkansson Sören
Published: July 2016

The C14 measurements reported here were made in this laboratory between October 1968 and October 1969.