APPLICATION OF THE PROTON MICROPROBE TO DIAMOND EXPLORATION AND GENESIS

The HIAF proton microprobe is being used to analyze trace elements in mantle-derived minerals, including garnets, ilmenites, and chromites. The goals are to understand mantle processes and to improve the use of indicator minerals in diamond exploration programs. Interpretation of the data provides new information on magma compositions and fractionation mechanisms, metasomatic processes, time scales of heating and melt infiltration, and the environment of diamond formation. Trace-element data on indicator minerals improve discrimination between barren and diamondiferous source rocks, and help to recognize the presence of multiple source rocks within one drainage; they will also ultimately help to improve the models that guide exploration. © 1990.