On the possibility of determining rates of removal of uranium from crystalline igneous rocks using U-series disequilibria—2: applicability of a U-leach model to mineral separates
1987; Elsevier BV; Volume: 2; Issue: 1 Linguagem: Inglês
10.1016/0883-2927(87)90061-8
ISSN1872-9134
AutoresA.G. Latham, Henry P. Schwarcz,
Tópico(s)Geological and Geochemical Analysis
ResumoPreliminary U-series data are presented on the disequilibria of mineral separates of surface samples from the Eye-Dashwa lakes granite (Canada). Most analyses of the ferromagnesian, quartz-plus-feldspar, and zircon-plus-sphene grains, show that leaching of U has taken place such that234U/239U≤ 1 and 230Th/234U 1. The simple leach model presented in a companion paper was used to explain these characteristic ratios. It is suggested that the leach model may be used on zircon and sphere grains to estimate U-leach rates, and this is relevant to the suggestion of using sphene-like hosts as the primary barrier in the safe disposal of nuclear waste. A full analysis of U mobility within a given rock volume was not possible due to our limited data base and to our inability to monitor labile U directly.
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