October 2013

Following in the footsteps of the emperor

Senegal’s three distinct regions each hold promise

By Pierrick Blin and Antoine Dion-Ortega

In the 13th century, the Emperor of Mali, Mansa Musa, whose domain spanned 10 modern-day countries including Senegal, brought so much gold from his land on his pilgrimage to Mecca that the price of the precious metal plummeted for many years. Although phosphate has been Senegal’s main asset since the mid-20th century, gold might be about to make a comeback, with new discoveries on the way and many mining companies attracted by the political stability of the country.

Senegal is divided into three geological zones, with each of them holding notable mineral deposits. The coast between the capital city of Dakar and Saint-Louis, near the border with Mauritania, is composed of black sands rich with zircon and ilmenite, a titanium-iron oxide mineral. These sands, brought in by the sea, could be a product of the crystal shale found in the sand structures of the West African coast. Zircon, which was historically used in the jeweller’s craft, has more recently been applied to the management of radioactive waste. Demand for titanium, a byproduct of ilmenite, has been growing in the last few years, due in large part to the mineral’s use in both biomedical equipment and the aeronautics industry.

These growing markets have helped launched the Grande Côte Operation SA project (commissioning expected in the first quarter of 2014), which will be the world’s third-biggest zircon mine. Tizir, a joint venture between France’s Eramet and Australia’s Mineral Deposits Limited, owns 90 per cent of the project, with the remainder held by the state. This half-billion-dollar project could produce 85 kilotonnes per annum (ktpa) of zircon and 575 ktpa of ilmenite over a 20-year mine life.

Beneath these dunes just a few kilometres inland lies Senegal’s great sedimentary basin, which covers three quarters of the country. To the east, it contacts the Precambrian base of the Mauritade Mountains, and towards the west the basin deepens, reaching six to eight kilometres deep near the coast. On this savannah, phosphate has been king for half a century now. Formed during the middle and lower Eocene epoch, phosphate deposits were first exploited in the 1940s with the opening of the Taiba and Lam-Lam mines in the region of Thies. These deposits contributed to the success of the Senegalese economy for several decades, leading to the construction of most of the country’s infrastructure, including the railway, which was required to transport the fertilizer to the Port of Dakar, 70 kilometres away.

Today, phosphate accounts for 13 per cent of the country’s exports, with overall production nearing one million tonnes per year. Besides the Taiba fields, other known deposits in the northern regions of Matam, Coki, Gossas and Niakhene, which could be of even higher quality, have yet to be developed. These fields could boost the country’s reserves to one billion tonnes and propel Senegal into the world’s top 10 producers, according to Senegal’s Ministry of Mining and Energy.

Phosphate fields in the Thies region have been historically controlled by Senegal’s state-owned Industries Chimiques du Senegal. But the government has shown a growing interest in private foreign investment in the mining sector, which could reach $5 billion this year, according to Tracy Weslosky, publisher for the InvestorIntel website.

Back to gold

The Precambrian rock basement in the east of the country has also caught the attention of exploration companies, especially the paleoproterozoic volcanosedimentary sequences of the Birimian formation that could hold gold deposits.

In the last decade, mining activities in the region have intensified. Teranga Gold’s Sabodala mine, the country’s first large-scale gold project, came into operation in 2009. In 2012, it produced more than 210,000 ounces of gold. Other companies, such as Randgold with its Massawa project and Iamgold with its Boto project, are hoping to duplicate Teranga’s success.

These companies have been attracted by the Birimian greenstone belt that runs through West Africa. “Essentially, Senegal has extensions of geological units that what we have seen in Ghana, Guinea, and Mali, specifically known hosts to significant gold deposits,” explains Craig MacDougall, senior vice-president for exploration at Iamgold.

The Birimian greenstone belt was even the birthplace for some of these companies. “Iamgold was born out of making a discovery and developing a mine in Mali, and really, our interest in Senegal was tracing those favourable geological environments across the border into Senegal,” says MacDougall.

Senegal’s greenstone belt is divided into three stratigraphic units: the Mako Supergroup to the west, the Diale Supergroup in the middle, and the Dalema Supergroup to the east. The Sabodala deposit and many ongoing exploration projects are located in the Mako Supergroup, in a shear, silicified zone containing gold pyrite mineralization. The tectonic structure forms a northeast oriented belt, curving to the northwest near the Malian border.

“This corridor is one of the most prolific ones as far as hosting gold deposits,” says Martin Lanctot, mine manager at Sabodala mine. “It’s not only us. Just 40 kilometres away in Mali, there are a lot of other deposits, and if you go east all the way to Burkina Faso, there are operations which are producing gold, and some of those assets belong to other Canadian companies. Basically, we’re all following the same trend, or the same mineralization corridor.”

Everybody agrees that current activities in the region are in the early stages, as the whole belt could hold huge potential. “What we’re mining is a portion of a bigger trend that is going across West Africa, if you look at it through a macroscopic perspective,” says Lanctot.

“I believe the future in Senegal looks promising,” MacDougall adds.

Although Senegal probably will not match its past emperor’s power to change the price of gold, the mining sector could nevertheless contribute to brightening its future.

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