Dating of Humus Podzols By Residual Radiocarbon Activity

Perrin, Sean; Willis, E. H.; Hodge, C.A.

doi:10.1038/202165a0

Cited by 52 publications

(20 citation statements)

References 7 publications

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“…From this analysis of situation it must be concluded that the 'age of soil' obtained by application of radiocarbon dating techniques and calculations represents a reliable scientific result only when interpreted as the minimum age. This wellunderstood situation has been expressed before by several authors (Perrin et al, 1964;Geyh etal., 1971). An immediate consequence of this analysis is the important fact that the chronological order of a given set of soils cannot be established from their respective minimum ages.…”

Section: Problems Of Soil Datingmentioning

confidence: 76%

Soil radiocarbon analysis and soil dating

Scharpenseel

Schiffmann

1977

Geophysical Surveys

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Abstract. Based on 14C dating principles, techniques of measuring 14C concentrations in pedogenic organic materials have been well established. Basic lines of soil sample pretreatment for radiocarbon analysis by liquid scintillation are shown. Possible influences of lithogenic carbon on the results obtained are discussed.Soil organic matter 14C analysis results can-according to the radiocarbon dating formula-be interpreted as minimum ages of the soil under investigation if strong evidence for autochthonous pedogenic origin of the material is given. In case of fossil soils, minimum age is maximum estimate for period of burial. The gap existing between minimum age and true age can be reduced by special techniques of fractionation, as well as by taking account of additional pedological information on turnover features of the material. Discussion of possible soil organic matter turnover mechanisms leads to a theory of rates of decomposition high in the initial stages and slowing down to nearly zero with time.Application of 14C techniques to humus dynamics until now yielded apparently contradictory results on relative ages of different humic matter fractions. Enrichment of old material in the HC1 hydrolysis residue fraction, however, has been observed in all instances.Mathematical modelling of soil radiocarbon response on varying turnover parameters results in estimates of turnover time and migration speed of soil organic matter in total as well as fractions thereof. Zusanmlenfassung. Ausgehend von den Grundlagen der 14C Datierung wird das Verfahren der 14CMessung an organischem Bodenmaterial mit Hilfe der Flfissigkeits Szintillations Methode kurz erl~iutert. Ernste meJ3technische Probleme liegen heute nicht mehr vor. Als Mangel wird die uneinheitliche Probenvorbereitung bei CaCO 3 haltigen und CaCO3 freien Proben empfunden.Die bodendynamisch bedingte altersm~J3ige Inhomogenitfit der Proben erm6glicht es nicht, das 'wahre Alter' einer Probe, d. h. das Alter des filtesten Tells der in der Probe enthaltenen organischen Stofte nach der Datierungsformel zu berechnen. Eine genaue Analyse zeigt vielmehr, daJ3 der nach der Formel berechnete Wert nur als Minimalabsch~itzung flit das Alter der Probe gesichert ist. Das so ermittelte Minimalalter der untersuchten organischen Substanz ist gleichzeitig ein Minimalalter fiir den zugeh6rigen Boden, falls feststeht, da~ das erfaJ3te Material autochthon pedogen ist und weder aus dem Ausgangsmaterial stammt noch durch Lateraltransport in den Boden gelangte. Das Minimalalter fossiler B6den ist gleichzeitig eine Maximalabschfitzung ihrer Uberdeckungszeit.Dutch Isolierung einer an filterem Material angereicherten Fraktion der organischen Substanz und ihre gesonderte Untersuchung kann ein Minimalalter ffir den untersuchten Boden gewonnen werden, das dem 'wahren Alter' n~iher kommt. Effolge wurden bisher mit der Rfickstandsfraktion von HC1 Hydrolysen erzielt. Die Frage nach der Fraktion h6chsten Alters ist noch often.Ober das durch Fraktionierungsmethoden gewonnene MaJ3 hinaus kann Aufschlu...

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Section: Problems Of Soil Datingmentioning

confidence: 76%

Soil radiocarbon analysis and soil dating

Scharpenseel

Schiffmann

1977

Geophysical Surveys

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“…: period well-known for cool and moist climate, favorable to development of this phenomenon. If compared to ages obtained for B horizon of podzol by Perrin et al (1964) and Scharpenseel et al (1968), podzols studied here seem rather older.…”

mentioning

confidence: 90%

Gif Natural Radiocarbon Measurements IV

Delibrias¹,

Nakhla²,

Labeyrie³

1969

Radiocarbon

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“…Some of the above-mentioned authors have therefore introduced the terms "the apparent mean residence time" or "equivalent age" for the values obtained. However, interpretation of these values remains difficult (Perrin and Willis 1964;Geyh et al 1971).…”

Section: Introductionmentioning

confidence: 99%

Estimating Turnover of Soil Organic Carbon Fractions Based on Radiocarbon Measurements

Bruun¹,

Six

Jensen³

2005

Radiocarbon

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ABSTRACT. In this paper, we examine 3 different models used to estimate turnover of soil organic carbon (SOC) fractions using radiocarbon measurements: one conventional carbon dating model and two bomb 14 C models. One of the bomb 14 C models uses an atmospheric 14 C record for the period 22,050 BC to AD 2003 and is solved by numerical methods, while the other assumes a constant 14 C content of the atmosphere and is solved analytically. The estimates of SOC turnover obtained by the conventional 14 C dating model differed substantially from those obtained by the bomb 14 C models, which we attribute to the simplifying assumption of the conventional 14 C model that the whole SOC fraction is of the same age. The assumptions underlying the bomb 14 C models are more applicable to SOC fractions; therefore, the calculated turnover times are considered to be more reliable. We used Monte Carlo simulations to estimate the uncertainties of the turnover times calculated with the numerically solved 14 C model, accounting not only for measurement errors but also for uncertainties introduced from assumptions of constant input and uncertainties in the 14 C content of the CO 2 assimilated by plants. The resulting uncertainties depend on systematic deviations in the atmospheric 14 C record for SOC fractions with a fast turnover. Therefore, the use of the bomb 14 C models can be problematic when SOC fractions with a fast turnover are analyzed, whereas the relative uncertainty of the turnover estimates turned out to be smaller than 30% when the turnover time of the SOC fractions analyzed was longer than 30 yr, and smaller than 15% when the turnover time was longer than 100 yr.

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Dating of Humus Podzols By Residual Radiocarbon Activity

Cited by 52 publications

References 7 publications

Soil radiocarbon analysis and soil dating

Soil radiocarbon analysis and soil dating

Gif Natural Radiocarbon Measurements IV

Estimating Turnover of Soil Organic Carbon Fractions Based on Radiocarbon Measurements

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