Page 30 - FWG Issue 6 July 2024

Estate News

THE VREDEFORT DOME –

A UNIQUE GEOLOGICAL PHENOMENON

hile producing for the History in 1876, the town’s name translates to “peace the largest known meteorite impact
Channel, Fourways Gardens fort” in Afrikaans and Dutch. It’s a reminder structure on Earth.
Resident Sian Clark discovered of the peaceful settlement that avoided war
Wthat the largest impact between what was then the Boer Republics So, what was it? An asteroid or
structure still known on earth is 142km away of the Transvaal and the Orange Free State. meteorite?
from Fourways Gardens, in Vrederfort. Well, in fact, both. The difference is simple.
It’s fitting that a town with so much history Asteroids are the original body orbiting the
Imagine two billion years ago when life was hit by this gigantic meteorite two billion sun. Meteorites are the asteroid fragments
on earth was at its most primitive. At this years ago and is now the setting for the that enter the Earth’s atmosphere and collide
time, a meteorite roughly the size of Table Vredefort Dome. with our planet.
Mountain came hurtling through space and
hit an area outside what would become – “The Vredefort crater is a very, very old, very The meteorite which hit Vredefort was
Johannesburg, the city of gold. eroded remnant of a mighty big asteroid twice as big as the rock, which killed off
impact,” says Professor Graeme Addison, the dinosaurs over a billion years later in
The impact turned the earth inside out and who lives and works in the dome region. Chicxulub, Mexico.
embedded the previously exposed gold
reefs, which would become the foundation Wits Professor of Geology Roger Gibson The Chicxulub crater is about 160km across,
of South Africa’s mineral wealth in years to says: “The Vredefort crater, so far, is the and that wiped out 75% of all life on Earth.
come. largest impact structure that we know on
Earth. Therefore, it sits on the extreme, it is Professor Roger Gibson is the recognised
The event took less than 10 minutes but evidence of the worst damage done to the authority on the Vredefort Dome. He has
changed the planet forever. planet’s surface.” published two field guides and a book on
the impact structure.
This is the Vredefort Dome and how that It was only in the early 1980s, when the
single cataclysmic event influenced the space shuttle sent satellite images back “This was a planetary changing event. The
development of South Africa’s economic to Earth that people realised this wasn’t a meteorite impact was so strong that it not
future. volcano crater as previously thought. This only exposed rocks from deep within the
was a unique geological phenomenon. Earth, but it also upturned over 25km of the
Vredefort is a small farming town in the Free Earth’s crust. Leaving it lying bare on the
State province of South Africa. Established This is the oldest, and at 300km in diameter, surface,’ he says.

Map of Vredefort Dome Crater rock formation

Fourways Gardens • 28 • July 2024