The Kenieba Diamond Region - Mali, West Africa

The Kenieba diamond region of Mali is considered prospective for diamonds and new discoveries thereof because of the following attributes and observations:
• The area is underlain by stable, Precambrian crust that was cratonised around 2000 million years ago
• Area of basement uplift evidenced by a thinning of the platform cover to expose the Kenieba inlier
• Parts of the basement are overlain by younger sediments making the area favourable for the preservation of the upper levels of a pipe, where diamonds grades are generally higher
• A cluster of 29 kimberlite pipes and dykes are known from the area
• Some of the know pipes contain diamonds, albeit in low concentrations
• Relatively large diamonds have been recovered from two pipes: Bilali Sud (7.4ct) and Cirque (6.1ct).
• A number of very large diamonds have been found in alluvium close to some of the pipes (232, 137, 102, 98, 72cts)
• The diamond content of pipes within any given field can be extremely variable and so the low diamond grades of the known pipes does not automatically preclude the potential for a high-grade pipe in the field.
• Most of the 29 pipes discovered to date are rich in picroilmenite and magnetite. In many kimberlite fields there is a negative correlation between diamonds and these minerals.
• To date, very little exploration has focussed on finding pipes that are poor in picroilmenite and non-magnetic
• A number of diamond and indicator mineral occurrences cannot be explained by the known pipes and suggest as yet undiscovered kimberlites.