Advertisement

Kimberlite Terminology and Classification

  • B. H. Scott SmithEmail author
  • T. E. Nowicki
  • J. K. Russell
  • K. J. Webb
  • R. H. Mitchell
  • C. M. Hetman
  • M. Harder
  • E. M. W. Skinner
  • Jv. A. Robey
Conference paper

Abstract

Description, classification and interpretation of kimberlites and related rocks, and communication of that information, underpin the development of three-dimensional geological models used in generating reliable diamond resource estimates. A rationalisation of kimberlite terminology and classification is presented in a practical, systematic framework or scheme. The scheme has five stages and is based on progressively increasing levels of interpretation building upon a series of descriptors that are applied independently of, and prior to, genetic classifications. Stage 1 of the scheme is rock description (alteration, structure, texture, components) and involves only limited genetic interpretation. The components are ascribed to three classes: compound clasts (kimberlitic, mantle, crustal), crystals, in particular olivine, and interstitial matrix (groundmass, interclast cement or clastic matrix). Kimberlitic compound clasts include magmaclasts (e.g. solidified melt-bearing pyroclasts), lithic clasts (e.g. autoliths) and accretionary clasts. Where possible, subsequent stages involve classification and higher levels of interpretation, based on increasing degrees of genetic inference. Stage 2 is the petrogenetic classification into parental magma type and mineralogical type. Stage 3a is the broad textural-genetic classification into coherent kimberlite and volcaniclastic kimberlite. In Stage 3b, coherent kimberlite is further subdivided into intrusive kimberlite or extrusive kimberlite, and volcaniclastic kimberlite into pyroclastic kimberlite, resedimented volcaniclastic kimberlite and epiclastic volcanic kimberlite. Pyroclastic kimberlites can be assigned into two main classes: Kimberley type (formerly tuffisitic kimberlite) and Fort à la Corne-type (formerly pyroclastic kimberlite). Stage 4 incorporates an assessment of the spatial relationship to and the morphology of the kimberlite body from which the rocks under investigation derive. Stage 5 involves more detailed genetic interpretation with more specific classification based on the mode of formation.

Keywords

Kimberlite Terminology Classification Nomenclature Diamond Exploration Evaluation Mining 

Notes

Acknowledgments

Discussions over several decades with many colleagues in particular pioneers, Barry Hawthorne, Roger Clement and the late Barry Dawson have provided a foundation to this contribution. Jocelyn McPhie is gratefully acknowledged for sound advice and encouragement especially during early parts of the development of this scheme and for expert teachings over the years. Jocelyn’s thorough, detailed and constructive comments as reviewer of this and an earlier manuscript were very much appreciated and significantly improved this paper and the scheme. Many colleagues and clients are thanked for innumerable discussions that led to many of the concepts included in this paper. Russell Eley is acknowledged for the idea of the term pyrocryst to provide an excellent solution to a long-term terminology problem. This paper has benefited from discussions with Steve Sparks and his research group, participants of the 2006 Kimberlite Emplacement Workshop, and other members of the now disbanded IAVCEI Kimberlite Terminology Working Group (Ray Cas, Richard Brown, Matthew Field). Stuart Smith is thanked for professional assistance in drafting of tables and figures. Helpful comments by reviewer Richard Brown and guest editor Bruce Kjarsgaard are gratefully acknowledged. Thanks to guest editor Graham Pearson for his support and assistance in the publication process.

References

  1. Berryman AK, Scott Smith BH, Jellicoe B (2004) Geology and diamond distribution of the 140/141 kimberlite, Fort à la Corne, central Saskatchewan, Canada. In: Proceedings of the 8th international kimberlite conference. Lithos, vol 76, pp 99–114Google Scholar
  2. Brett RC, Russell JK, Moss S (2009) Origin of olivine in kimberlite: phenocryst or imposter? In: Proceedings of the 9th international kimberlite conference. Lithos, vol 112S, pp 201–212Google Scholar
  3. Cas RAF, Porritt L, Pittari A, Hayman P (2008) A new approach to kimberlite facies terminology using a revised general approach to the nomenclature of all volcanic rocks and deposits: descriptive to genetic. J Volcanol Geoth Res 174:226–240CrossRefGoogle Scholar
  4. Cas RAF, Porritt L, Pittari A, Hayman P (2009) A practical guide to terminology for kimberlite facies: a systematic progression from descriptive to genetic, including a pocket guide. Lithos 112 (Suppl 1):183–190CrossRefGoogle Scholar
  5. Clement CR, Skinner EMW (1985) A textural-genetic classification of kimberlites. Trans Geol Soc S Afr 88:403–409Google Scholar
  6. Clement CR, Skinner EMW, Scott Smith BH (1984) Kimberlite redefined. J Geol 92:223–228CrossRefGoogle Scholar
  7. Dawson JB (1971) Advances in kimberlite geology. Earth Sci Rev 7:187–214CrossRefGoogle Scholar
  8. Dawson JB (1980) Kimberlites and their xenoliths. Springer, Berlin, p 252CrossRefGoogle Scholar
  9. Field M, Scott Smith BH (1998) Textural and genetic classification schemes for kimberlite: a new perspective. Extended abstracts, 7th international kimberlite conference, Cape Town, pp 214–216Google Scholar
  10. Hawthorne JB (1975) Model of a kimberlite pipe. Phys Chem Earth 9:1–15CrossRefGoogle Scholar
  11. Hetman CM (2008) Tuffisitic kimberlite (TK): a Canadian perspective on a distinctive textural variety of kimberlite. J Volcanol Geoth Res 174:57–67CrossRefGoogle Scholar
  12. Hetman CM, Scott Smith BH, Paul JL, Winter FW (2004). Geology of the Gahcho Kué kimberlite pipes, NWT, Canada: root to diatreme magmatic transition zones. In: Proceedings of the 8th international kimberlite conference. Lithos, vol 76, pp 51–74Google Scholar
  13. McBean D, Kirkley M, Revering C (2003) Structural controls on the morphology of the Snap Lake kimberlite dyke. 8th international kimberlite conference, Victoria, Canada, Extended Abstract #258, p 5 Google Scholar
  14. McPhie J, Doyle M, Allen R (1993) Volcanic textures. Centre of ore deposit and exploration studies, University of Tasmania, p 196Google Scholar
  15. Mitchell RH (1986) Kimberlites: mineralogy, geochemistry and petrology. Plenum Publishing, New York, p 442Google Scholar
  16. Mitchell RH (1995) Kimberlites, orangeites, and related rocks. Plenum Press, New York, p 410CrossRefGoogle Scholar
  17. Mitchell RH, Skinner EMW, Scott Smith BH (2009) Tuffisitic kimberlites: mineralogical characteristics relevant to their formation. Lithos 112 Suppl 1):452–464CrossRefGoogle Scholar
  18. Mogg T, Kopylova M, Scott Smith B, Kirkley M (2003) Petrology of the Snap Lake kimberlite, NWT, Canada. 8th international kimberlite conference, Victoria, Canada, Extended Abstract #67, p 5Google Scholar
  19. Scott Smith BH (2008a) Canadian kimberlites: geological characteristics relevant to emplacement. J Volcanol Geoth Res 174:9–19CrossRefGoogle Scholar
  20. Scott Smith BH (2008b) The Fort à la Corne kimberlites, Saskatchewan, Canada: geology, emplacement and economics. J Geol Soc India 71:11–55Google Scholar
  21. Scott Smith BH, Nowicki TE, Russell JK, Webb KJ, Hetman CM, Harder M, Mitchell RH (2008a) Kimberlites: descriptive geological nomenclature and classification. 9th international kimberlite conference, Extended Abstract No. 9IKC-A-00124, p 3Google Scholar
  22. Scott Smith BH, Nowicki TE, Russell JK, Webb KJ, Hetman CM, Harder M, Mitchell RH (2008b) Kimberlites: descriptive geological nomenclature and classification. Short Abstract and Poster, 36th Annual Geoscience Forum, YellowknifeGoogle Scholar
  23. Scott Smith BH, Nowicki TE, Russell JK, Webb KJ, Mitchell RH, Hetman CM, Harder M, Skinner EMW, Robey JV (2012) Kimberlites: descriptive geological nomenclature and classification. 10th international kimberlite conference, Extended Abstract No. 10IKC-A-226, p 5Google Scholar
  24. Scott Smith BH, Nowicki TE, Russell JK, Webb KJ, Mitchell RH, Hetman CM, Harder M, Skinner EMW, Robey JV (In Press) A glossary of kimberlite and related termsGoogle Scholar
  25. Scott Smith BH, Smith SCS (2009) The economic implications of kimberlite emplacement. In: Proceedings of the 9th international kimberlite conference. Lithos vol 112 (Suppl 1):10–22Google Scholar
  26. Skinner EMW, Clement CR (1979) Mineralogical classification of southern African kimberlites. In: Boyd FR, Meyer HOA (eds) Kimberlites, diatremes and diamonds: their geology, petrology and geochemistry. American Geophysical Union, Washington, pp 129–139CrossRefGoogle Scholar
  27. Wentworth CK (1922) A scale of grade and class terms for clastic sediments. J Geol 30:377–392CrossRefGoogle Scholar
  28. Woolley AR, Bergman SC, Edgar AD, Le Bas MJ, Mitchell RH, Rock NMS, Scott Smith BH (1996) Classification of the lamprophyres, lamproites, kimberlites and the kalisilite-, melilitic- and leucitic rocks. Can Mineral 34:175–186Google Scholar

Copyright information

© Geological Society of India 2013

Authors and Affiliations

  • B. H. Scott Smith
    • 1
    • 3
    Email author
  • T. E. Nowicki
    • 2
  • J. K. Russell
    • 3
  • K. J. Webb
    • 2
  • R. H. Mitchell
    • 4
  • C. M. Hetman
    • 2
    • 5
  • M. Harder
    • 2
    • 6
  • E. M. W. Skinner
    • 7
  • Jv. A. Robey
    • 8
  1. 1.Scott-Smith Petrology Inc.North VancouverCanada
  2. 2.Mineral Services Canada Inc.North VancouverCanada
  3. 3.Department of Earth, Ocean and Atmospheric SciencesUniversity of British ColumbiaVancouverCanada
  4. 4.Department of GeologyLakehead UniversityThunder BayCanada
  5. 5.SRK Consulting (Canada) Inc.VancouverCanada
  6. 6.Tetra Tech IncVancouverCanada
  7. 7.Rhodes UniversityGrahamstownSouth Africa
  8. 8.Rockwise Consulting CCKimberleySouth Africa

Personalised recommendations