Geochemical Journal, Vol. 2, pp. 71 to 86, 1968.
Alpha radioactive nuclides of uranium, protactinium
and thorium in uranium deposits
,
MASANOBU SAKANOUE, SHOJIRO YONEDA*1 KOICHI ONISHI*2
KENJI KOYAMA*2, KAZUHISA KOMURA*3 and
TAKASHI NAKANISHI
,
Department of Chemistry, Faculty of Science
Kanazawa University, Kanazawa, Japan
(Received February 5, 1968; in revised form July 9, 1968)
Abstract-Uranium deposit samples were radiochemically separated for thorium,
protactinium and uranium and each fraction was submitted to alpha ray spectrometry
for the determination of 238U, 234U,231Pa, 232Th and 230Th. In an ore body of NingyoToge Mine, Okayama, Japan, the relationship between the uranium isotopes and their
daughter nuclides indicates an extensive migration of uranium. The migration was
also verified by the high radium and protactinium contents of a manganese nodule
sample. The thorium - bearing samples in a neighboring district were also analyzed
to elucidate the origin of these uranium deposits. The ages of two secondary
uranium minerals in Tono district, Gifu, were estimated to be 5 x 103 y and 34 x 103 y.
on the basis of their isotopic compositions. For the radioactive phosphate samples
in Noto district, Ishikawa, secondary enrichment of uranium by phosphate was
confirmed with their isotopic compositions and their phosphate contents.