Radiocarbon, Volume 22 (1980)
Radiocarbon
JournalRadiocarbon (130)AuthorsStuiver, Minze (8)Oeschger, Hans (6)Münnich, K. O. (4)Becker, Bernd (3)Bruns, Michael (3)Hewson, A. D. (3)Linick, T. W. (3)Polach, H. A. (3)Stipp, J. J. (3)Burleigh, Richard (2)View MoreTypestext (130)Article (76)Proceedings (49)Journal (3)Book review (2)Subjectsabsolute age (54)abundance (2)Acer macrophyllum (1)Africa (3)Alachua County Florida (1)View More
Radiocarbon is the main international journal of record for research articles and date lists relevant to 14C and other radioisotopes and techniques used in archaeological, geophysical, oceanographic, and related dating.
This archive provides access to Radiocarbon Volumes 1-54 (1959-2012).
As of 2016, Radiocarbon is published by Cambridge University Press. The journal is published quarterly. Radiocarbon also publishes conference proceedings and monographs on topics related to fields of interest. Visit Cambridge Online for new Radiocarbon content and to submit manuscripts.
Contact the University Libraries Journal Team with questions.
Radiocarbon, Volume 22, Number 4 (1980)
American Journal of Science, 1980-01-01
Radiocarbon, Volume 22, Number 3 (Proceedings of the 10th International Radiocarbon Conference, 1980)
Stuiver, Minze (American Journal of Science, 1980-01-01)
Editorial Statement to Contributors
Workshop on 14C Reporting
W. F. Libby and the Archaeologists, 1946-1948
Marlowe, Greg (American Journal of Science, 1980-01-01)
Archaeologists began to participate in cross-disciplinary endeavors in the 1930's, albeit on a very limited basis. The passage of time found members of that discipline unprepared for collaboration with physical scientists when W F Libby announced the development of the radiocarbon dating method. Libby proposed to apply to archeologic and geologic samples techniques based on ideas that were completely foreign to archeology.... The initial reactions of archeologists were sometimes amusing but more often significant, for they led to the foundation and emergence of the radiocarbon chronology that has so profoundly affected our understanding of prehistory (Johnson, 1967, p 165). To date, our historical knowledge about the nature, function, and impact of the early (1946-1948) relations between Libby and American archaeologists has come to us in the form of published anecdotes, many of which contain inaccurate information. The author's access to W F Libby's private 14C correspondence, combined with data obtained from interviews with some of the principal participants throughout this period, offers many new or different insights into the nascent years of radiocarbon dating. When, and under what unexpected cricumstances, did Libby first encounter representatives of the achaeologic community? What strategies were employed to facilitate diffusion of knowledge about 14C dating across disciplinary boundaries? How did archaeologists respond to the introduction or "intrusion" into their field of Libby's radioactive age-measurement tool?
Vienna Radium Institute Radiocarbon Dates X
Felber, Heinz (American Journal of Science, 1980-01-01)
Vertical Advection—Diffusion Rates in the Oceanic Thermocline Determined from 14C Distributions
Quay, P. D.; Stuiver, Minze (American Journal of Science, 1980-01-01)
The characteristics of a one-dimensional vertical advection-diffusion ocean mixing model were examined using temperature, salinity, and bomb 14C measurements made during the GEOSECS program. Vertical advection (W) and eddy diffusion (K) rates for the main oceanic thermocliine and CO2 gas exchange rates (E) were determined from the depth distributions of salinity and bomb produced 14C measured in the upper 1000m of the Atlantic and Pacific Oceans. In the Atlantic, the results suggest that vertical diffusion rates are lower in the equatorial region (K = 0.6cm2sec-1) than in the temperate region (K = 1.6cm2sec-1). Upwelling rates were calculated for stations located between about 30 degrees N and 30 degrees S and average 10m yr-1, corresponding to an upward transport of about 10 Sverdrups. Model calculations of the gas exchange rate of CO2 indicate a 2 to 3-fold decrease between temperate latitudes and the equatorial latitudes of the Atlantic. For many of the Pacific GEOSECS stations, the Delta-14C depth distribution is distinctly different than in the Atlantic, and cannot be used to calculate unique values of K and W that explain both the salinity and 14C depth distributions.
Variations of 14C in Oats Grown from 1957 to 1978 in Quebec
Barrette, Louis; La Salle, Pierre; Martel, Yvon; Samson, Claude (American Journal of Science, 1980-01-01)
Annual atmospheric radiocarbon concentrations for the year 1957 to 1978 are measured through oat seeds grown in the rural region of La Pocatière, Quebec (70 degrees W, 47 degrees N). Results follow the general pattern of other curves obtained from grains elsewhere in the northern hemisphere. Some disagreements suggest a non-uniform mixing process with faster response to stratospheric contamination in definite regions.
Use of 39Ar and 14C for Groundwater Dating
Loosli, Heinz Hugo; Oeschger, Hans (American Journal of Science, 1980-01-01)
Cosmic-ray produced atmospheric 39Ar activity (T1/2 = 269 yr) has been determined at 0.11 +/- 0.012 dpm/lt argon. Ice samples from two profiles in Greenland bore holes showed conclusively that 39Ar dating leads to correct ages. Corrections can be made for possible contamination of the samples with ambient air during field extraction and during laboratory processing by measuring 85Kr in the same samples. The following isotopes: 14C, 39Ar, 85Kr, 3H, partly 32Si, 13C, and 18O were investigated in 20 groundwater samples. Unexpectedly large discrepancies between "14C ages" and "39Ar ages" were observed for many of these samples. For example, a horizontal profile of a confined sandstone aquifer in the Franconian Albvorland showed decreasing 39Ar and 14C activities from respectively, 100 percent to 17 percent and 80 percent to 0.3 percent of modern activity, corresponding to elapsed time periods of 700 and >20,000 years, respectively. It seems unlikely that gas exchange through the aquiclude is the cause of this discrepancy. It can neither be explained by only assuming that the water represents a mixing of components with different ages. We detected the possibility of underground production of 39Ar in thermal spring water from Zurzach, Switzerland. Its argon showed higher specific activity than atmospheric argon. Elsewhere, however, samples were found containing no detectable 39Ar activity: two wells of a confined carstic aquifer in Ingolstadt, Germany, show less than 7 percent atmospheric activity. In our opinion, the assumptions on which the 14C method in hydrology are based need to be critically re-examined. It is possible that for some aquifers carbonate exchange between solid and liquid phases in the aquifer changes 14C results to a larger degree than generally assumed.
Variations in Radiocarbon Production in the Earth's Atmosphere
Korf, Serge A.; Mendell, Rosalind B. (American Journal of Science, 1980-01-01)
We have investigated solar phenomena associated with unusual changes in the production rates of 14C in the atmosphere. 14C is produced in interactions of cosmic ray neutrons with nitrogen in the atmosphere. Intensity of the neutrons varies globally and fluctuates with time as a result of interactions of galactic cosmic rays which generate neutrons with plasma and magnetic fields of the solar wind. We estimate the total mean production rate of 14C for solar cycle 20, specifically 1965 to 1975, to be 2.25 +/- 0.1 nuclei-cm-2sec-1 from galactic cosmic rays alone, with negligible integrated contribution from solar particle events. Annual averages of Rz, the Zurich sunspot number, and the production rate of 14C, n(14C), were related by n(14C) = 2.60 5.53 x 10^(-3) Rz, +/- 3 percent. The contribution of solar flare particles and the zero sunspot limit are discussed with relation to major fluctuations that appear in the radiocarbon versus dendrochronology over short (~100 years) integration times.
University of Wisconsin Radiocarbon Dates XVII
Bender, Margaret M.; Baerreis, David A.; Bryson, Reid A. (American Journal of Science, 1980-01-01)
Unreliability of 14C Dates from Organic Matter of Soils
Gilet-Blein, Nicole; Marien, Gérard; Evin, Jacques (American Journal of Science, 1980-01-01)
Contamination by recent carbon and the turnover of organic matter make dating of ancient soils difficult. In order to isolate the oldest organic fraction of sediments, two main extraction methods were previously proposed: 1) alkaline solubilization of humus that separates humins, humic acids, and fulvic acids, and 2) successive hydrolyses that solubilize increasingly resisting products. Both preparation methods were tested on the same actual or fossil soils of different pedologic types from five geologic profiles on which other chronologic data are available. Analytic results show that 14C ages obtained from alkaline extraction products differ according to the duration of treatments and characteristics of soils: while hydrolysis should yield more homogeneous results and isolate oldest fractions. It seems likely that true ages of geologic formations were never obtained from their organic matter and that the oldest organic fraction, contemporaneous with the sediment formation, completely disappears. Thus, most ages from 14C dating of organic matter of soils must be too recent.
University of Texas at Austin Radiocarbon Dates XIV
Valastro, S.; Mott Davis, E.; Varela, Alejandra G.; Ekland-Olson, Carolyn (American Journal of Science, 1980-01-01)
University of Miami Radiocarbon Dates XVII
Johnson, R.; Introne, D. S.; Mattes, J.; Stipp, J. J. (American Journal of Science, 1980-01-01)
University of Miami Radiocarbon Dates XVIII
Johnson, R. A.; Stipp, J. J. (American Journal of Science, 1980-01-01)