Zircon geochronology and Hf isotopes of the Dwalile Supracrustal Suite, Ancient Gneiss Complex, Swaziland: Insights into the diversity of Palaeoarchaean source rocks, depositional and metamorphic ages

The data support the model suggesting amalgamation between the AGC and BGB terranes at ca. 3.23 Ga. In addition, they require crustal thickening in the AGC terrane at ca. 3.15 Ga, causing Barrovian-type metamorphism in the DSS and granulite-facies metamorphism in the Luboya-Kubuta Terrane. Low-P granulite-facies metamorphism at ca. 2.99 Ga is most likely related to crustal extension during the onset of Pongola Basin rifting, causing mantle upwelling, mafic magmatism, and heat transfer from the mantle into the thinned crust.