학술논문
U/Th dating of impure carbonates: 230 Th/232 Th activity ratios in detrital material.
Document Type
Article
Source
Subject
*THORIUM isotopes
*RATIO & proportion
*CARBONATES
*DROPLETS
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Language
ISSN
0236-5731
Abstract
In environmental age dating the 230Th/232Th activity ratio is widely used as an indicator of detrital contamination. A clear relationship between this activity ratio and the carbonate sample's age has previously been demonstrated, whereby a detrital correction must be applied when the 230Th/232Th activity ratio of the leach drops to 20. We demonstrate that in some cases carbonate samples with 230Th/232Th well above 20 must be corrected, otherwise an overestimation of the sample's age is obtained. Evaluation of the relationship between 230Th/234U and 230Th/232Th in the carbonate's aliquots will enable evaluation of the limit at which a carbonate can be considered pure or impure. [ABSTRACT FROM AUTHOR]