The extensive Senegal-Mauritanian Basin covers most of Senegal and is composed of Mid-Jurassic to Recent, poorly cemented marine sands, marls, limestones and shales overlain by continental lacustrine and marine sediments.

The GCO project is within the belt of coastal dunes that lie along the current shoreline. The dunes, recent in age, are mobile or semi-fixed, pale yellow in colour and overlie older Late Quaternary white marine sands. The dunes range between 5m and 35m in height and the mineralised zones, which are essentially flat-lying, average around 15m in thickness.

The GCO deposit comprises a linear series of Aeolian sand dunes containing an HM assemblage concentrated by wind action. The Aeolian or mobile dunes overlie a substratum of former beach sands representing a recessive littoral environment. These sands also contain a lesser HM concentration. The natural water table generally occurs close to the interface between the mobile dune and littoral sand together with occasional peaty materials preferentially located at the dune-littoral sand interface.

The deposits include: Mboro, Lompoul, Diogo, Fass Boye, Yodi, Mboro Hotel and Noto. The deposits extend over a length of about 70km. There is potential for additional deposits beyond the limits of present drilling, both to the south–west and north–east for a total strike length drilled of 75km.

Dimensions
The resource extends for 75km north–east and averages 2km wide. T ........

At the Grande Côte Operations, the extraction operations take place in an artificial mobile basin of 12 hectares and about 6 metres deep and follow a route which is optimised to exploit the deposit. The mining process involves a dredge with a capacity of 7,000 tonnes per hour.

The world’s largest mining dredge (50 meters long and 17 meters wide) operates on a 600-meter long and 300-meter wide artificial pond, 24 hours a day. It moves about 30 meters per day— between 7 and 13 kilometers per year. The extracted sand is sent to the Wet Concentration Plant (WCP), which is connected to the dredge by a 320-meter long pipe.

The path design consists of mining three-dimensional designs defined by digitising. The shape and sequence of mining are controlled by the dredge and the floating plant constraints.

Dredges are well suited to large, free flowing sand deposits where a pond can be maintained. As the orebody consists of free-flowing sands holding an extensive shallow aquifer and high-grade located at the top, the choice of a dredge feeding the floating concentrator is appropriate for this deposit. However, dozer push is introduced to recover adjacent high-grade material to the mine path within 100m distance and slope angle of 15°.

No pre-strip is required. All material, within the design, is mined as ore.

Slopes are 35° above water and 14° below.

The optimum dredge pond level, to economically mine at and maintain the ........

- subscription is required.

- subscription is required.