The distribution of radioactivity in the major rock forming minerals

Abstract

The distribution of uranium (as determined by the nuclear emulsion method) and radioactivity is traced in the felspar, pyroxene, and quartz of the differentiated Skaergaard intrusion. It is characteristic that the radioactivity from the micro (and macro) inclusions in the major minerals progressively increases in the differentiated sequence towards the later members. The activity from inclusions is generally greater than that from the host mineral.

The Skaergaard intrusion is compared to various granites, granophyres, and basalts. The heterogenous distribution of radioactivity, related to the distribution of the accessory minerals, is shown by the Standard Granite G 1.

In all the rocks examined the uranium, and radioactivity, even at the low levels encountered, always showed a characteristic pattern.