Natural radioactivity of soils

Reprinted from the New Zealand Journal of Science and Technology, Vol. 37, no. 3, November 1955, pp. 354-368.
The radioactivity of principal horizons of a number of soil types was examined for relationships to properties used in the identification and classification of soil profiles. Techniques for measuring the intensity of gamma radiations in the field and of beta radiations in the laboratory are described. After correction for cosmic ray background the measurements showed a range in gamma counts from 410 c.p.m. to 2420 c.p.m. and in beta counts from 21 c.p.m. to 154 c.p.m. Correlation of the data and soil profiles showed that the soil radioactivity depends partly on the rock materials from which the profiles are developed and partly on the extent of weathering and leaching of the profiles.