40Ar-39Ar laser probe dating of individual clinopyroxene inclusions in Premier eclogitic diamonds

The ages of seven individual clinopyroxene inclusions in Premier diamonds of eclogitic association have been determined using the 40Ar-39Ar dating technique. Syngenetic inclusions weighing between 10 and 130 micrograms were exposed on cleaved surfaces of the diamonds and analysed using a laser probe. The inclusion ages were found to be in the range 1111 +/- 35 to 1254 +/-38 Ma with an average of 1185 +/- 94 Ma. The ages obtained are in good agreement with previous determinations made on aggregates of eclogitic inclusions from Premier diamonds and demonstrate the applicability of the laser probe to dating individual diamond inclusions.