Page 31 - Intra Muros October Issue 2025

ESTATE NEWS

This gave rise to various debates and
published articles in the geomorphological
and geological communities. The Vredefort
Dome was not like any geomorphological
structure that one could climb, like a
mountain, or view from the other side,
such as the Victoria Falls. It is described as
“an indentation, a seemingly flat area with
a few hills on the one side”.

It was only when the first photos of the
dome were taken from the Space Shuttle
in the 1980s that the world’s geological
community took a closer look at it. The
“hole in the ground” became something
they could see. This ultimately led to the
current status of the dome as a UNESCO
World Heritage Site known as the Vredefort
Dome Impact Structure.

An interesting fact – how a vote
decided that the Vredefort Dome is
an impact crater
- It all happened at the July 1987
International Conference on
Catastrophes in the Geological Record
and Cryptoexplosion Structures
(convened in Parys, South Africa). Geological map showing the different strata of the dome
- Many papers were presented.
- Arguments for and against were voiced. “a conical fragment of rock that has (ii) in the form of sharp, pointed rock
- Evidence was presented in various forms: striations radiating from the apex and shards; (iii) in the form of high-pressure
(i) in the form of shattercones (defined that is formed by high pressure, as and high-temperature forms of silica
by the Merriam-Webster dictionary as from volcanism or meteorite impact); (crystals of coesite and stishovite); and
(iv) in the form of melt rocks and glasses
– all proof of extreme pressures, too high
for volcanic activity.
- Ultimately, a vote was taken. All the
experts present confirmed that what was
then called the Vredefort crater was a
large and complex impact structure, with
the Vredefort dome being the rebound
central core.
- The word “structure” was coined in the
1990s to replace the use of the word
“crater” to explain the extent of the
asteroid impact.

This site became a UNESCO World Heritage
Site in 2005.

An example of melt rocks and glasses – example of shock metamorphism

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