Influence of matrix diffusion and exchange reactions on radiocarbon ages in fissured carbonate aquifers

Journal Article · Thu Aug 01 00:00:00 EDT 1991 · Water Resources Research; (United States)

DOI:https://doi.org/10.1029/91WR01110· OSTI ID:5963696

Maloszewski, P ^[1]; Zuber, A ^[2]

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1. GSF-Inst. fuer Hydrologie, Neuherberg (West Germany)
2. Inst. of Nuclear Physics, Cracow (Poland)

The parallel fissure model coupled with the equation of diffusion into the matrix and with exchange reaction equations has been used to derive a simple formula for estimating the influence of matrix porosity and reaction parameters on the determination of radiocarbon ages in fissured carbonate rocks. Examples of evidently too great radiocarbon ages in carbonate formations, which are not explainable by models for the initial {sup 14}C corrections, can easily be explained by this formula. Parameters obtained for a chalk formation from a known multitracer experiment combined with a pumping test suggest a possibility of {sup 14}C ages more than three orders of magnitude greater than the ages which would be observed if the radiocarbon transport took place only in the mobile water in the fissures. It is shown that contrary to the solute movement on a small scale and with a variable input, the large-scale movement, characteristic for the {sup 14}C dating, does not necessarily require the knowledge of kinetic parameters, because they may be replaced by the distribution coefficient. Discordant tritium and {sup 14}C concentrations are commonly interpreted as a proof of mixing either in the aquifer or at the discharge site. For fissured carbonate formations, however, an alternative explanation is given by the derived model showing a considerable delay of {sup 14}C with respect to nonsorbable tracers.

• OSTI ID: 5963696
• Journal Information: Water Resources Research; (United States), Vol. 27:8; ISSN 0043-1397
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
54 ENVIRONMENTAL SCIENCES
AQUIFERS
ISOTOPIC EXCHANGE
SORPTIVE PROPERTIES
GROUND WATER
FLOW MODELS
ISOTOPE DATING
CARBON 14
CARBONATE ROCKS
CHEMICAL REACTION KINETICS
DIFFUSION
GEOLOGIC FRACTURES
MATHEMATICAL MODELS
POROSITY
ROCK-FLUID INTERACTIONS
TRACER TECHNIQUES
TRITIUM
AGE ESTIMATION
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBON ISOTOPES
EVEN-EVEN NUCLEI
GEOLOGIC STRUCTURES
HYDROGEN COMPOUNDS
HYDROGEN ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LIGHT NUCLEI
NUCLEI
ODD-EVEN NUCLEI
OXYGEN COMPOUNDS
RADIOISOTOPES
REACTION KINETICS
ROCKS
SEDIMENTARY ROCKS
SURFACE PROPERTIES
WATER
YEARS LIVING RADIOISOTOPES
580000* - Geosciences
540220 - Environment
Terrestrial- Chemicals Monitoring & Transport- (1990-)