Mining in focus
Mining in focus
Map of the gold basins in South Africa.
Harmony Gold has developed the Target Mine,
one of the later additions to gold mining in
that region. Immediately north of Target is a
zone of gold enrichment that could possibly be
described as a new ‘fan’, the Paradise Fan, where
some initial drilling has been undertaken,”
Theart explains.
As far as Mining Mirror could establish,
Anglovaal (later AVGold) explored this area
in the past and discovered the Target and
Paradise Fan. Similarly, there are known
lower-grade gold deposits on the south-
eastern and eastern side of the Basin, north-
east of the Free State Goldfield.
Wanless agrees but adds that there are a
number of challenges in the Bothaville Gap.
“For one, the cover is much thicker here. So
those reefs would be deeper than for example
at Harmony’s Target Mine, and the company’s
Loraine Mine to the south of Target,” says
Wanless. Both Target and Loraine initially
mined the Basal Reef and the B-Reef, which
are the bottom economic reefs in the Free
State Goldfields. Today, Target is also mining
the Elsburg Reef, a set of stacked reefs that
require massive mining methods, similar to
what Goldfields has to deal with, at times, at
its beleaguered South Deep Mine on the Far
West Rand Goldfield of the Witwatersrand
Basin. The Basal and B-Reefs are very deep,
and although the Elsburg Reef occurs near
the top of the sequence, they are extremely
challenging to explore and to find the areas
that contain the high-grade mineralisation.
Adding more goldfields
Up to now, geologists have identified eight
established goldfields, namely the South
Rand Goldfield; Evander Goldfield; East
Rand Goldfield; Central Rand Goldfield;
West Rand Goldfield; Carletonville
Goldfield; Klerksdorp Goldfield; and the
Free State Goldfield. To the north-east of
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the Free State Goldfield possibly lies another
goldfield, which could be referred to as the
Ventersburg Goldfield.
The potential Ventersburg Goldfield to the
east of the Free State Goldfield was explored
extensively by AngloGold Ashanti and much
more recently by Gold One. Unfortunately,
the excitement seems to have waned, again
possibly because of the increased risk of
committing to a long-term exploration and
mining development project.
Are we looking in the right places?
According to Professor Terence McCarthy,
emeritus professor of geology at Wits
University and principal geologist at Shango
Solutions, we are probably still not looking in
the right places. Although the Witwatersrand
Basin is punted to be the area where the
next big gold discovery will be made, there
are other regions in South Africa that could
be prospective. These include the Barberton
Greenstone Belt in Mpumalanga, which is the
oldest gold region in the country and offers,
according to Hunt, potential for shorter-term
shallow operations (Ed’s note: Barberton is a
subject for another time and Mining Mirror
will run an extensive feature on the Greenstone
Belt in Barberton in the near future. Hunt is an
expert on the Barberton Greenstone Belt.)
“We have done several studies and
looked at the complete distribution of the
Witwatersrand-type rocks, and it turns out
that they are much more extensive than
originally thought,” says McCarthy. He adds
that there are potentially two new areas
containing Witwatersrand rocks. “We’ve
mapped out the full distribution of upper and
lower Witwatersrand rocks using information
available in the public domain. They stretch
from Johannesburg all the way to Colesberg
in the Karoo and eastwards to Bethlehem,
where there are possibly other gold-bearing
MAY 2019 MINING MIRROR [23]
MAY 2019 MINING MIRROR [23]