Page 35 - Intra Muros October Issue 2025

ESTATE NEWS

Prokaryotes thrive in these environments
due to their ability to harness energy from
the vent’s minerals with their own internal
chemistry, allowing them to grow.

During and after the forming of the
Witwatersrand strata, these prokaryotes
lived in-between the oxygen-free layers,
precipitating gold and pyrite, which is also
called “fool’s gold” (a sulphur compound
results in the yellow colour), into these
layers. That’s the reason fool’s gold is
sometimes an indication of possible real
gold being embedded in rock.

The prokaryotes metabolised dissolved
minerals in the hydrothermal underground
fluids, extracting, enriching and
concentrating the gold. They were
instrumental in shedding and binding
the gold to other mineral surfaces,
accumulating concentrated gold into mats
or a ‘golden lacework’.

A few interesting points:
- One of the most fascinating facts
about the area is that you can literally
see the Earth’s crust on the edge.
- Another fact is that the Vaal River is
the only major river on Earth to flow
through an impact crater, and the
river itself is one of the oldest on
the planet. It certainly occupies what
may be the oldest river catchment on
Earth, the Witwatersrand basin, that
dates back three billion years.
- Here, too, the first continent on
Earth was formed in what is now
both Southern Africa and Western
Australia.
Why is the gold of the Witwatersrand - Prokaryotes* enriched and concentrated - After the Ice Age, large trees grew
the greatest and richest find on the gold by metabolising dissolved in the inland seas/lakes that formed
Earth? minerals in underground hydrothermal as a result of melting ice, when the
As you would have realised by now, if it fluids. continents drifted to warmer parts of
was not for the asteroid, the South African - Gold ended up being deposited in dense Earth. These marshes and large trees
gold deposits would not have been here seams. became coal deposits on top of what
to mine; it would have eroded away and was then Earth’s top layer – you will
‘washed to sea’! Prokaryotes* see the position of the coal layer in
Procaryotes are bacteria that can thrive one of the images above.
- Not only was the gold preserved by in harsh and hot environments with no
the impact, the impact also tilted it oxygen. They still exist today at fissures
vertically, so it was buried deep under of the crust and ocean floor, living in the There is so much more that one can write
the Earth’s current crust, or it was funnel-like fumaroles found in this hot, about this amazing phenomenon just on
formed by geological processes. mineral-rich water. our doorstep. Visit and see it for yourself.

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