Geophysical Methods in Terrestrial Material Property Determinations.

In-house and contractual research was conducted on the relationships between mechanical strength properties of rock and soil material and their electrical properties. A theoretical study involved the quantum electromagnetic and elastic interactions of crystals and solids. Laboratory and field investigations were made of the porosity and surface crack networks of large masses of quarry rocks, which govern their conductivity and permittivity. Thermal and mechanical stressing of rocks were analyzed. Electrical parameters of deep mine rocks were measured in-situ with emphasis on frequencyconductivity relationships. Direct mapping of rock strength as a function of electrical resistivity was investigated in the field. A three-dimensional modeling program was conducted in the laboratory. Field measurements of dynamic electrical conductivity of various earth materials were made under conditions of a rapid stress generated by high explosive setonations. Correlations demonstrated by this geophysical and geological research can be useful in prediction or evaluation of nuclear weapon shock effects on military installations.