Outcrop of the oldest-dated rocks in Africa near Piggs Peak, Swaziland. Zircons from this outcrop of the Ngwane gneisses of the Ancient Gneiss Complex gave an age of 3.644 Ga (upper intercept).
Compston, W., Kroner, A., 1988. Multiple zircon growth within early Archean tonalitic gneiss from the Ancient Gneiss Complex, Swaziland. Earth.Plan.Sci.Lett. 87, 13-28.