GEOLOGY
About the Author
Dr Nicolaas Steenkamp has a decade and a half of post-qualification experience in the
geological and geotechnical industry. He has been involved in a variety of consultation
activities ranging from exploration, geochemistry, geological and geotechnical, desktop
studies, due diligence, EPCM contracts and related feasibility studies.
www.bowlineps.co.za
Nic
Africa. There is onshore exploration for hydrocarbons that is
sporadically undertaken. It is estimated that Benin has 1.09Mt
of crude petroleum and 1.1 billion cubic meters of natural gas.
The Benin Basin has been the subject of intensive studies and
exploration over the last half century.
Cement was produced by Ciments du Benin S.A., Société des
Ciments d’Onigbolo, and Société des Ciments du Benin. The
other industrial minerals mined include limestone, marble,
clay, sand and gravel. Due to excessive sand mining along
the beach, the mining of beach sand was outlawed. The
mining of sand deposits moved inland, but there has been
severe backlash from the affected communities. Historically
phosphate was mined along the Mekrou River in the northern
region of Benin.
Low grade iron ore deposits are described in the Loumbou-
Loumbou and Madekali areas in the Borgou district, estimated
at approximately 500 million tons of ore. Low grade, near
surface supergene manganese occurrences have been
reported from various locations in central Benin.
Premier African Minerals is exploring Proterozoic magmatic
gneisses in the central region of Benin. The area previously
attracted artisanal miners to the pegmatite veins that host
tantalum and coloured gemstones such as tourmaline and
aquamarine. It is also indicated that topaz and chrysoberyl may
be present too.
Government’s role in mining
According to the mining convention in Benin, the government
is the custodian of all mineral deposits. Any company
interested in exploring or engaging in mining activities
are required to sign a government contract and establish
headquarters in Benin. It is also required that an accredited
representative be appointed prior to the start of any activities.
The royalty rate varying between 5% and 15%, depending on
the commodity.
o l a a s St e e n k a m p
The government of Benin undertook a major operation to
stop most artisanal mining operations to facilitate formal
exploration and mining operations. Between 2013 and 2014
a large scale airborne geophysical survey was undertaken.
The results indicated the potential of new deposits being
discovered.
Infrastructure challenges
As with most developing African nations, Benin is still facing
the challenges of infrastructure. The road and railway systems
are dilapidated, and the port facilities are in need of major
upgrades and modernisation. The energy grid is insufficient to
support major industry or other energy intensive operations.
The country has only one international airport and seaport
and two major highways connecting it with the neighbouring
countries. In addition, the country has a knowledge shortage
and intensive drives to increase education levels are needed.
Over the last decade there has been a massive construction
programme undertaken in the capital city, that stimulated
the industrial mineral sector, but has resulted in severe
environmental damage.
The economy
Cotton is the main contributor to the GDP, accounting for
approximately 80% of official exports. The rest of the country is
largely dependent on subsidence agriculture. Benin is hoping
to increase its economic activities by encouraging the country
to be used as a port to access the landlocked countries of West
Africa. Tourism has also been touted as doorway means to
attract more foreign investment.
Benin has an opportunity to benefit from the increase of
exploration and mining investment and spending in West
Africa. The country appears to have significant unexplored
or under-explored mineral deposits. The main challenge of
the country will be to both attract investors while in parallel
addressing the infrastructure limitations.
Geology of Benin
The north of Benin is dominated by the Proterozoic Dahomeyide orogen crystalline rocks, divided into a series of north-
northeast trending belts. Of the six lithotectonic terrains, four are present in Benin. Zone 1 comprises of sandstone,
dolomite and limestone and minor volcanic intrusions. Zone 2 is a thin unit of basic and ultrabasic that is inferred to
represent either mantle diapirs or an ophiolitic complex. Acidic magmatic and a range of metamorphic rocks make up
Zone 3. Finally, Zone 4 is represented by several NNE to SSW trending schist belts surrounded by a gneissic-migmatitic
complex. There is a sharp contact along the 7th latitude with the southern Cretaceous to Holocene sedimentary rocks.
The stratigraphy is dominated by sandstone, sand and a variety of clays. Along the north-eastern border with Niger,
extensive Neogene alluvial deposits are developed.
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African Mining Publication
African Mining
African Mining February 2020
35