Swartrante translates to Black Ridges from Afrikaans.

They are a stark contrast to the pink granite gneiss they are intruded into.

They are also significantly more resistant to weathering, therefore they form ridges and low hills.

The process of intrusion faulted, sheared and otherwise altered the gneiss it was being forced into.

This shearing is visible in patches all along the contact zone between the two rock types.

The Swartrante are composed entirely of Metagabbro, a rock that contains no quartz and is made up entirely of dark ferromagnesian minerals and feldspar.

The black iron/manganes crystals can be seen contrasting with the lighter feldspar crystals in freshly broken rocks.

As the crystals weather, due to the elements, the manganese coats the outside of the rocks with a thin black coating, giving them their characteristic colour.

The metagrabo layer was exposed by the folding processes very evident from the air, more especially in the rocks to the west of the Swartrante.

This folding was part of the uplift associated with the breakup of Gondwanaland and the formation of the African continent.

Other posts in this series.

Augrabies - The hidden river
Augrabies - The Falls and Floods
Augrabies: a "heart of stone" for valentines day.
Augrabies: Reading the geological history written on the walls
Augrabies: Lizards everywhere
Augrabies: Further examples of weathering and erosion types
Augrabies: Moon rock
Augrabies: how moon rock was formed and is continuing to being shaped
Augrabies: Warps, twists and valley widening
Augrabies: Moon rock - not only interesting to us.