A 'lattice-defect; free energy' approach to replacement processes in ore deposition

The probability is discussed of a close interrelationship between i) concentrations of lattice defects and associated free energy in minerals; and ii) solid state and chemical reactivity processes, in the formation of some ore deposits. The distributions of lattice defects and/or free energy near four base metal sulfide ore deposits, as indicated by thermoluminescence, are analyzed and the conclusion reached that lattice defects due to strain may have played a very significant part in pre-ore ground preparation and the localization of the ore zones. Defects caused by low-level radioactivity and some trace elements should have similar effects, but in one, if not all, of the cases examined they appear to have been of negligible importance. It is suggested that in cases where obvious structural or petrologic controls for the emplacement of ore deposits appear to be lacking, the controls may have been inconspicuous concentrations of either lattice defects or above normal free energy.