Tswaing Nature Reserve, Gauteng
Just off the R35 north of Pretoria, the Tswaing (Setswana for place of salt) Nature Reserve is incredibly beautiful. It houses not only a number of wild animals and a large variety of birds, trees and plants, but it is also the place of a 220 000 year old crater, the impact of a huge meteorite said to be between 30 and 50 metres in diameter. The impact site is one of the best-preserved and youngest in the world and, if you exclude Arizona's famous meteor crater, one of the most accessible.
The Tswaing crater is definitely the star of the show. Lying virtually in the centre of the Tswaing nature reserve, it has an elevated circular rim set roughly 60 metres above the surrounding bushveld. On its floor is a brine lake. Evidence of Stone Age and Iron Age remains at Tswaing indicate that the basin was a part of our predecessors lives. However, it was only during the 1990s that evidence proved that this crater was caused by a meteorite. Before this, there was rife speculation that it was an old volcano.
The meteorite was probably about the size of a an average house and it would have taken no more than 10 seconds to slam into the ground after entering the Earth's atmosphere, releasing the energy of about 100 Hiroshima atom bombs. Life within a 35 kilometre radius would have been wiped out.
Although the Tswaing is considered far less important, geologically speaking, than the Vredefort Dome, it is a lot more pleasing on the eye, as well as being southern Africa's only example of a lake within a crater caused by a meteorite collision. Unfortunately, before the value of the crater site was understood, the lake was the site of a commercial salt-making operation.
Today the Tswaing Nature Reserve is a sanctuary with a small interpretation centre and museum and fairly popular for picnics.
Did you know?
The Tswaing meteorite crater is one of four known impact craters in South Africa and one of about 170 impact craters in the world.