| Onverwacht Group | |
| Period: | Paleoarchean |
| Age: | Paleoarchean > |
| Type: | Geological group |
| Prilithology: | Greenstone belt |
| Otherlithology: | Volcanic rock |
| Subunits: | Subunits |
| Underlies: | Fig Tree Formation |
| Thickness: | 16370m (53,710feet) |
| Map: | South African Greenstone Belt.png |
| Coordinates: | -25.8°N 31°W |
| Region: | Barberton Greenstone Belt, Mpumalanga |
| Country: | |
| Extent: | Kaapvaal Craton |
The Onverwacht Group or Onverwacht Series is a series of greenstone belts and volcanic rock formations from the Archean Eon in the Kaapvaal Craton in South Africa and Eswatini.
A well known part of the Onverwacht Series is visible in the Komati valley, located in the east of the Transvaal region.
The Onverwacht Group can be divided into two subgroups with six formations:
The fossils found in the Onverwacht Series are among the oldest found on Earth.[1]