Summary
Gamma-ray spectra of the samples were measured by standard laboratory multichannel spectrometry. The weighted least squares method was applied to the digital output data in order to determine the concentrations of U238, Th232 and K40 present. U and Th increase towards the rim of the massif (from 4 ppm U and 20 ppm Th in the coarse-grained central facies to 23 ppm U and 42 ppm Th in the fine-grained rim variety), whereas K remains fairly constant at ∼3.85%.
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On leave Eidgenössische Technische Hochschule, Zurich (Switzerland)
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Rybach, L., von Raumer, J. & Adams, J.A.S. A gamma spectrometric study of Mont-Blanc granite samples. PAGEOPH 63, 153–160 (1966). https://doi.org/10.1007/BF00875165
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DOI: https://doi.org/10.1007/BF00875165