Autoradiographic studies on some lamprophyre and mudstone

Abstract

The radioactive order of rocks, namely, of the lamprophyre dykes in Kitashirakawa granite, Kyoto City, and of the Tertiary mudstone¹⁾ common in Nachi District, Wakayama Prefecture was studied autoradiographically with ET nuclear emulsion: the average alpha track number per centimeter square was found per day 7.28±1±0.34 in the former and 15.98±1.17 in the latter; these two values were compared with those of some other rocks.