Nuclear Methods for Subsurface Prospecting

Abstract

A survey was made of literature pertaining to nuclear techniques for measuring in situ the properties of subsurface formations. The nuclear methods reviewed are those in which (a) the response of the emission of prompt or delayed gamma rays and/or neutrons is observed in irradiated geological formations and (b) the natural or spontaneous emission of gamma rays and/or neutrons by geological formations is observed. A description is given of the techniques applied in aerial and surface prospecting. The economic importance of subsurface prospecting and the fundamental limitations of the nuclear techniques are indicated. Following a discussion of existing boundary conditions, considerations are given of the status of each nuclear method. The review is concluded by identifying major gaps in the methods and by commenting on the future course of the development of methods for subsurface prospecting. 86 references. (B.O.G.)