Ian McGeorge Orapa 50 Kukama kimberlites

1. Discovery of the
Kukama kimberlites,
CKGR
Ian McGeorge
iQuest

2. The Kukama “kimberlites”
 A cluster of four small diamondiferous intrusions
of evolved “kimberlite” with Group II or
lamproitic affinity.
 Discovery 1996 by Canadian junior TNK
Resources Inc.
 Program initiated and managed by MPH
Consulting Ltd, Toronto.
 Later evaluation in joint venture with De Beers
Prospecting.
 Part of the 1990s “diamond exploration boom”

3. Location of the Kukama kimberlites

4. The story starts far away

5. NXAUNXAU

6. Detailed location of the Kukama kimberlites

7. Kukama – aeromagnetics
(Petra Diamonds 2007)

8. TNK Resources – initial licence block

9. Distribution of Karoo basalt

10. AEROMAGNETIC
DATA
CENTRAL
KALAHARI
2VD

11. AEROMAGNETIC DATA
TSABONG AREA
2VD

12. Go 173N, Go173S, Go 211 and Go 234 Ground
Gravity and Magnetic Follow-up
Go173 N
Go173 S
Go211
Go234
Go173 S
Go173 N
Go211&
Go234

13. Go173S: Kimberlite Intersections – March 2007
Analytical Signal Bouguer Gravity – 1st Vertical Derivative
Go173 S
Go211
Go234
TNK/De Beers RC Boreholes (K/B – EOH Lithology)
Sekaka Boreholes
TNK Discovery Intersection
TNK/De Beers Diamond Borehole
100m
BH GO173S/H8
BH GO173S/H9
Gravity Model Contours

14. GO173-South Gravity
(Petra Diamonds 2007)

15. Drilling

16. Kimberlite slimed under the drill

17. GO173-North: downhole chemistry in discovery
hole

18. TNK Core Drilling Patterns

19. Petrography
 The Kukama kimberlites are evolved rocks and exhibit
features more typical of Group II or lamproitic intrusions.
 Go173N is hypabyssal facies and highly diluted, with 50%
basalt xenocrysts.
 Go211 and 234 contain both crater and hypabyssal facies.
 The indicator mineral suites are dominated by garnet and
spinel. Ilmenite is rare. G10 garnets are rare. However
34-45% of the garnets are eclogitic and these show
elevated Na2O consistent with presence of diamonds.
 Diamond inclusion spinels are present, but in very low
abundances

20. Kukama mineral chemistry (from De Beers)

21. Kukama Kimberlites – De Beers mini-bulk sample results
Kimberlite Area (ha) Sample (t) cpht (+1mm)
Go173N 3 43.74 0.31
Go173S small 21.25 2.98
Go234 1 19.54 8.02
Go211 2 19.70 0.94

22. Conclusion
 The Kukama discoveries, though not apparently economic,
were probably the most significant discoveries in Botswana
during the 1990s diamond exploration boom. The last word
on Kukama has yet to be written.
 Kukama led Petra Diamonds towards the discovery of KX-
36.

23. Lessons from the TNK program
 Good area selection – on craton, close to Go25
discovery (Ghaghoo Mine). Large initial area of
6,700 km2
 Add value to existing aeromag data.
 Effective aeromagnetic target screening by heavy
mineral sampling – identified one very anomalous
site.
 Routine geochemistry and down-hole indicator
mineral sampling identifies kimberlite not
recognised on the drill site.
 Delineation of kimberlite bodies by core drilling.

24. Lessons from the TNK program (2)
 MiDA and KIM studies showed kimberlites
to be diamondiferous.
 When unable to raise further exploration
funding in post Bre-X era, entered into JV
with De Beers.

25. Were there any discoveries during the 1990s
diamond exploration boom?
 The 1990s boom triggered work on a number of
kimberlites in Lesotho & South Africa. MPH
pioneered evaluation of the Liqhobong pipes,
Lesotho, which were artisanal workings. Now
held by Firestone Diamonds plc and the
Government of Lesotho, Liqhobong has just gone
into commercial production.

26. Liqhobong, Lesotho. 1990s evaluation concurrent with work at Kukama,
but now in production

27. Thanks
 Happy to try to answer your
questions.