COUNTRY IN FOCUS
mineral and metal substances, including gold and platinum,
base metals (iron, copper, chromium, nickel), industrial
minerals (limestone, salts, barytine) and heavy minerals
(zircon and titanium) have been largely unexplored and
unexploited in Senegal until recently. “However, thanks to
the significant investment promotion efforts made by the
Senegalese government, the diversification of mining activity
is developing through the development of the phosphates-
fertiliser sector, the revival of the integrated iron project in
Falémé, the accelerating gold mining in the Kedougou region,
supervising and promoting artisanal mines, accelerating the
GEOLOGY AND MAJOR
OPERATIONS IN SENEGAL
By Nicolaas C Steenkamp
Western Africa’s oldest rocks from the Archean or Proterozoic
Birimian basin is also found in Senegal. The Birimian rocks
consist of metabasic, meta-andesite, breccia and greywacke
and schist and contain the gold mineralisation found in
Senegal. In the Kedougou inlier, these meta-sedimentary
rocks were intruded by granite plutons during the Eburnean
orogeny. In the south-eastern part of Senegal, the Madina-
Koukta Basin developed during the Neoproterozoic period
outcrops along the edge of the inlier. Two more basins
were developed during the Early Cambrian period and are
known as the Komba and Faleme Basins, the latter being
filled with later carbonates and tillites related to a glaciation
period during the Paleozoic. The Faleme Basin contains
the carbonate-hosted iron deposit, the magnetite and iron
hydroxides contain up to 60 % iron. Alluvial diamonds are
also found in the Faleme and Gambia Rivers. Heavy mineral
exploration has also been conducted in these rivers.
The Senegal-Mauritania Basin is one of the largest marginal
basins that formed during the rifting of Pangaea during the
Mesozoic. The basin has a length in excess of 1 400km and
is up to 500km in width at its widest point near Dakar. The
sedimentary units in this half-basin increase in thickness
towards the coast, with most of the material deposited
during the Oligocene. The sedimentary series starts with
Triassic evaporites, gypsum, anhydrite and halite with
coincidence of tholeiitic magmas. By the Cenozoic the ocean
retreated, and the region was subjected to intense terrestrial
weathering. The Cap-Vert peninsula experience peaks of
volcanism during the Miocene and during the Quaternary,
resulting in Mamellles volcano and associated vent and flow
structures, consisting of undersaturated alkaline lavas. The
large phosphate reserves in Senegal were formed during
the Cenozoic and Eocene when the switch from marine
to continental environment led to the enrichment of lime
phosphates to aluminium phosphates. In addition, this area
host deposits of limestone, palygorskite, clay, dolomite and
heavy minerals and aggregate.
Off-shore resources include gas and oil. Oil was discovered in
Senegal in 1961 in the Dima Naido field. The Dome Flore on
the border with Guinea Bissau is indicated to host a heavy oil
field in shallow water and a number of on-shore gas fields.
Mining operations
Prior to 2008, the Senegalese mining sector was, and
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African Mining February 2020
exploitation of zircon deposits and developing a regional
mining hub,” says Ott.
Consistent regulations
Mining regulations in Senegal have been reasonably
consistent, which creates some sort of certainty. “However,
O’Connor says that the mining sector might take a leaf from
the hydrocarbons industry which ratified a new petroleum
code in January 2019 and that has already led to renewed
interest among investors. “Senegal’s mining code has been
consistent but has not necessarily resulted in significant
continues to be, dominated by the phosphate sector,
where it was locally processed into phosphoric acid and
derived products. The Matam phosphate lime project
started in 2014 and was producing 1.2 million tons of
material by 2018. More exploration and research are being
conducted on the phosphate fields in the central part of
the Basin. The establishment of a fertilizer plant is the next
goal set by the government.
Cement is also domestically produced from limestone, with
other raw products such attapulgite clay and salt source in
the same region. In 2019 there are three cement factories in
Senegal, with the potential to not only supply the planned
construction initiatives in-country, but also export to
neighbouring countries, such as the Ivory Coast that have
mills, but need to import all the clinker.
The gold mining sector in Senegal is relatively nascent in
contrast to neighbouring Ghana. The oldest commercial
gold mine in Senegal is the Sabodala Gold mine, discovered
in 1961 the deposit is located about 650 km east of Dakar.
The first pour took place in 2009 and the mine expansion
program was completed in 2012. The mine has reserves in the
order of 1.70 million ounces (oz) of gold from the Sabodala,
Niakafiri, Gora and Sutuba deposits.
Resolute Mining made a USD305-million offer to take over
privately held Toto Gold’s Mako gold mine in July 2019. The
Mako gold mine was constructed in 2016 with the first pour in
2018, making it only the second commercial scale gold mine
in the country. The mine has a targeted production of 300
000oz and indicated to host a mineral resource of up to 1.22
million oz and a reserve of 928 00oz of gold in 2019. The mine
has a ROM head grade in excess of 2.5 g/t for the projected
six-and-a-half-year life-of-mine. The processing facility is an
industry standard CIL plant comprising a crushing circuit,
a SAG mill and a gold extraction circuit prior to discharge
to a lined tailings facility via a cyanide destruct circuit. The
operation is powered by a diesel fuelled 14 MW power station.
Reports emerged in April 2019 that illegal gold mining was
taking place in some of Senegal’s national parks, mostly
supported by Chinese nationals, that paid USD42 per
kilogram of gold delivered to them. This is only the tip of
illegal mining in Senegal, with tax revenue losses amounting
to several millions lost annually to such activities.
Mining of heavy mineral sand deposits is underway by
Grande Côte Operations (GCO) to increase the country’s
share of the world market, where it already supplies about
8% of the market and 25% of the European market. The
potential of manganese and lithium deposits located in the
eastern parts of Senegal are investigated for the potential
of development.
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