A detailed geochemical investigation of diamond-bearing eclogite xenoliths from the Kaalvallei kimberlite, South Africa
The eclogites are essentially bimeneralic assemblages of garnet and clinopyroxene. Thirteen xenoliths contain accessory diamond with graphite on diamond surfaces. One has accessory ilmenite. The rocks are well equilibrated and are classified as Group 1 eclogites, based on their mineral textures and compositions. The calculated equilibrium temperatures for the eclogites range from 1157 °C to 1245 °C, assuming a pressure of 50 kbar. Two populations of eclogites are defined in terms of the calcium content of the garnet, equilibration temperatures and trace element abundances.
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