Significance:
Archaean microfossils and microbial trace fossils (bacterial borings) have been recorded from cherts and volcanic glasses in similar-aged greenstone belts elsewhere in RSA (e.g. Fig Tree Group & Onverwacht Group of Barberton Greenstone Belt, Mpumalanga & Swaziland).
“Fly speck carbon” in sedimentary Uitkyk Fm of the Pieterburg Greenstone Belt, Limpopo, may be fossilised microbes,or alternatively of inorganic origin (e.g. an inorganic precipitate induced by radioactive irradiation).
Predominantly volcanic igneous rocks, plus some igneous intrusions, minor sediments such as banded iron formation, chert, quartzite, conglomerate, schists (e.g. Pietersburg Group, Uitkyk Fm, Giyani Group, Gravelotte Group) Rocks usually tectonised, highly metamorphosed
Early to Mid Archaean (Swazian - Randian)
3.5 – 3 Ga
Basic intrusions dated 3.5 Ga and younger
Greenstone Belts provide samples of the oldest known crustal rocks, including minor marine and terrestrial sediments, but the rocks here are usually highly deformed and metamorphosed.
