In 2013, the Government of Benin commissioned CGG Fugro Company to carry out the airborne magnetometric, radiometric and gravimetric survey of the entire territory of Benin. This aerial survey confirmed the indications of the existence of oil and mineral deposits, including, among others, gold, iron, phosphate and oil.
Examples of mineral resources available in Benin are:
Benin has significant gold reserves especially in the Department of Atacora. Some of them are the following:
DEPOSIT IN THE DISTRICT OF PERMA: It consists of 26 quartz veins spread over an area of 2 sq. km. The proven reserve amounts to 800 kg of lode gold at a grade of 9 g / ton.
ALLUVIAL DEPOSITS: They are located in the valleys of rivers in Perma, Sina- Issiré and Sarga. The alluvial gold reserve available is estimated at 400 kg with a grade of 1 g per cubic meter. That of the Sina-Isséré River is 1 ton with grades estimated at 1.2 g per cubic meter.
The metallic gold zone of Atacora was divided up into 18 mining perimeters of which: 12 were granted to mining companies. In the Department of Alibori, 8 mining areas are demarcated for the search for gold.
In the region of Karimama (northeast), there is the Loumbou-Loumbou deposit with reserves of 226 million tons containing 46-52% iron and 13-15% silica. At Madékali in the city of Kandi (northeast), there is an iron deposit with reserves amounting to 240 million tons, containing 46-52% iron and 13-15% silica
The phosphate deposit in the region of Mekrou to the northwest of Benin is estimated at 5.5 million tons with an average grade of 25.2% of phosphorus pentoxide. The phosphate ore is very useful in agriculture.
BUILDING MATERIALS AND FOSSIL FUELS
Benin’s subsoil contains many building materials including limestone, marble, clay, clayey earth, sand, gravel and ornamental stones.
Limestone deposits are estimated at 122.5 million tons, and can be used for the cement industry, those of cliffstone suitable for ballasting are estimated at 33 million tons and those used for lime are valued at 1.575 million tons. They are located at:
- Onigbolo: 90 million tons of reserves.
- Massè: 17.5 million tons.
- Avlan: 1.575 million tons (for the manufacture of lime)
- Bakpodji: 33 million tons of cliffstone suitable for ballast.
Marble is found in several districts in Bénin, including:
- Idadjo: This town is located 360 km north of Cotonou. The deposit is composed of calcareous-dolomitic rocks largely crystalline, of a gray-blue hue and with a fine polish. This reserve is estimated at 6 million tons;
- Motéwo: Town situated in the region of Alafia about 300 km north of Cotonou. It is a lenticular formation whose reserves have not yet been assessed.
- Atomè-Lonkly: In this locality, the reserve of twenty indications of dolomitic marble was assessed at 6.5 million cubic meters.
- Lanta: Located 15 km west of Abomey, this town has a deposit of 75,000 cubic kilometers of gray marble in lentils in migmatites.
Gravel deposits exist in the Region of Sê in the Department of Mono, with a reserve of 13,081,000 cubic kilometres and in Lokossa north of Sê.
Benin has a lot of ornamental stones. They are rocks which, sawed and polished, have a nice polish and can be used for covering floors and walls. There are:
- Granites in the districts of Dassa, Gobada, Fita, Parakou;
- Syenites and monzonites in the region of Bétérou;
- Jasper and serpentinite of Buem;
- granulites and charnockites in the area of Pototoumana-Kompagorou;
- granulites at Dérouvarou;
- eruptive alkaline complex of Pako.
Clay deposits have been identified in the coastal sedimentary basin. A few deposits can be listed: Gbedji-Kotovi: 5 million tons; Massi: 1.5 million tons and Zogbodomè: 10 million tons. Furthermore, Djrègbé, Sakété and the riparian area of Ouémé River revealed clay deposits which have not been assessed yet. They are used for making bricks and terracotta tiles.
Clayey earth is found on the plateaus of the coastal sedimentary basin, particularly south of Lama Depression. It is used in the manufacture of bricks and clay tiles.
Important kaolin reserves have been discovered and can be used for various applications: pottery, ceramics, sanitary fittings, tiles, white cement production. The reserves are estimated at 1 billion cubic meters of kaolin polluted by iron oxides in the district of Kétou and 1 million cubic meters of white kaolin in the area of Adakplamè.
Geological mapping and mineral exploration work have identified areas of peat in the southern Departments, including:
In the Department of Atlantique: between Cotonou and Hêvié and in the swampy valley of Kpomanou opening on Lake Toho; in the Department of Mono: swamp of Kpakpatan; in the Department of Ouémé: swampy depressions of Avrankou to Dogla Lago, between Sèmè junction and Djrègbé.
There are many mineral occurrences and useful substances requiring detailed work for their in-depth assessment. A few examples:
- microscopic diamonds: Magou and Kiatiko in the Department of Atacora;
- rutile (titanium ore): Birni, Péhunco, Tchaourou, Savè and Kétou;
- nickel: South of Tobré (Péhunco district);
- gypsum: Pobè, Bopa-Bakpodji; and
- tin group metals (tin, niobium, tantalum, tungsten, etc.) identified in the regions of Dunkassa-Kalalé and Sinendé.
The coastal sedimentary basin harbours hydrocarbon deposits. Exploration work helped discover geological structures that may contain hydrocarbons. The coastal basin was divided into six (6) blocks: Four (4) offshore blocks 1, 2, 3, 4 and two (2) onshore blocks A and B.
The estimated reserves of hydrocarbons at these different blocks reach seven (7) billion barrels of oil spread over three sites: Avrankou, Sèmè-Kpodji and Allada. These reserves are as follows:
- Crude oil: 5250 million barrels;
- condensate: 200 million barrels;
- gas: 91 billion cubic meters.