The re-convened 12th International Kimberlite Conference (12 IKC) comes at a time when high-quality petrologic, geochemical and isotopic data pertaining to kimberlites, diamonds and the Earth’s upper mantle are being generated, compiled, and released into the public domain at an astonishing rate. To help make sense of this tidal wave of new data and related geoscientific models, 12 IKC is convening two Seminars to address emergent topics related to (i) large Type-II diamonds and (ii) kimberlitic olivine.

Large Type-II (CLIPPIR and Type IIb) diamonds: genesis and transport to surface

Invited Speaker: Dr. Evan Smith, Gemological Institute of America

Supporting Speakers: To be announced

Expect to hear about:

  • Why do large Type II diamonds have low nitrogen concentrations?
  • Why are only some large Type II diamonds of exceptional gem quality while others are poor quality?
  • Are inclusion suites in large gem Type IIs different from inclusion suites in smaller, lower quality (Juina-type) Type IIs?
  • What is the geological significance of the metallic Fe-Ni-C-S inclusions in CLIPPIR diamonds?
  • Are there indicator mineral proxies for large Type II diamonds in primary deposits?
  • How old are large Type II diamonds? What are their mantle residence times?
  • What is the global distribution of large Type II diamonds in time and space?
  • How are sublithospheric diamonds transported upward and incorporated into kimberlites?

Kimberlitic olivine: tracking mantle cargo and kimberlite melt evolution

Invited Speaker: Dr. Geoffrey H. Howarth, University of Cape Town, South Africa

Supporting Speakers: To be announced

Expect to hear about:

  • Why has research (and publications) on kimberlitic olivine become so popular?
  • Overview of current research methods, analytical techniques and pitfalls related to the rejuvenated understanding of kimberlitic olivine
  • Why has a revised descriptive (zonal) terminology emerged for kimberlitic olivine, and what purpose(s) does it serve?
  • Discovery and interpretation of (former) melt inclusion(s) in kimberlitic olivine, with comparison to experimental and reconstructed primitive/parental kimberlite melt compositions
  • Chromite and other oxide inclusions in kimberlitic olivine
  • Practical tips on use of the Al-in-olivine thermometer
  • Mantle sampling as exemplified by (xenocryst) olivine entrainment patterns
  • Correlations between olivine core and rim compositions, with implications of mantle entrainment on kimberlite melt compositions

Each Seminar will last around 3 hours (including breaks) with a state-of-science invited presentation, two to three additional supporting presentations, and ample semi-moderated question-and-answer periods

The Seminars are integrated within the regular 12 IKC proceedings (i.e. Monday to Friday sessions) and are included in the 12 IKC registration fee. Herman Grütter is planning and coordinating the Seminars, with support from the 12 IKC Technical Program Committee Chairs Thomas Stachel and Graham Pearson.

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