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Mineralogy and Petrology

, Volume 112, Supplement 2, pp 339–350 | Cite as

The Liqhobong kimberlite cluster: an update on the geology

  • Mafusi RapopoEmail author
  • Paul Sobie
Original Paper
  • 53 Downloads

Abstract

The Cretaceous Liqhobong kimberlite cluster comprises six known diamondiferous Group 1 kimberlite bodies: the Main Pipe (8.5 ha), the Satellite Pipe (1.6 ha), the Discovery Blow (0.15 ha), the Blow (0.1 ha), the Main Dyke, and the East Dyke. Emplaced along a strike length of about 2.5 km, the kimberlites intruded Jurassic Drakensberg lavas and outcrop at altitude ranging from 2970 to 2670 m above sea level (masl) in the rugged Maluti Mountain terrain of Lesotho. The cluster’s intrusion was structurally controlled and emplacement occurred in at least three pulses. The dykes and the two blows (which are dyke enlargements emplaced ~900 m apart) comprise the earliest event and the Main and Satellite Pipes were emplaced during two separate, subsequent events. Each pipe has steep contacts with the country rock basalt. The two Blows have inward dipping contacts and narrow considerably at depth. Each of the Main and Satellite Pipes comprises multiple phases which range from largely volcaniclastic to marginally coherent kimberlites. The volume of the volcaniclastic kimberlite is always much more (>three times) than that of the coherent kimberlite. The larger Main and Satellite Pipes are diluted by country rock up to 40 vol% whereas the smaller Blows and Dykes typically have less than 10 vol% dilution. The degree of mantle sampling is highest (up to 40 vol%) in the smaller Blows and lower (~25 vol%) in the larger Pipes.

Keywords

Liqhobong Maluti mountain Lesotho Kimberlite Volcaniclastic Kimberley-type pyroclastic kimberlite (KPK) 

Notes

Acknowledgements

The authors would like to thank Stuart Brown, CEO of Firestone Diamonds plc, and Paul Bosma, General Manager of Liqhobong Mining Development Company (Pty) Ltd., for financing the attendance of the 11th International Kimberlite Conference (IKC) in Gaborone by MR. Much insight and different of opinions on the Liqhobong kimberlites were provided by several world experts at the 11th IKC. The networking and educational opportunities gained therein have been an eye opener and are greatly appreciated. We are also greatly indebted to two anonymous reviewers and guest editor Casey M. Hetman whose comments helped to greatly improve this manuscript.

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Copyright information

© Springer-Verlag GmbH Austria, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Liqhobong Mining Development CompanyMaseru WestLesotho
  2. 2.MPH Consulting LimitedTorontoCanada
  3. 3.Firestone Diamonds plc, The TriangleLondonUK

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