Principles of using microdiamonds for resource estimation: 1—The impact of mantle and kimberlite processes

CIM Journal , Vol. 7, No. 4, 2016

J. Stiefenhofer and M. L. Thurston
Technical and Sustainability, De Beers Group Services (Pty) Limited, Southdale, South Africa

D. M. Rose
School of Statistics and Actuarial Science, University of the Witwatersrand, Johannesburg, South Africa

I. L. Chinn
De Beers Exploration, De Beers Group Services (Pty) Limited, Southdale, South Africa

J. J. Ferreira
Johan Ferreira & Associates Ltd, Wokingham, Berkshire, United Kingdom

http://dx.doi.org/10.15834/cimj.2016.26
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Mots clés :
Résumé Des travailleurs se sont interrogés sur l’utilisation de microdiamants pour estimer la ressource; en effet, de multiples populations de diamants existent dans plusieurs secteurs de la région source dans le manteau. Des petits diamants dans la kimberlite pourraient être exposés à des niveaux proportionnellement supérieurs de résorption et de modification; de plus, des diamants idiomorphes pourraient cristalliser immédiatement avant l’éruption de la kimberlite. Le présent article traite de ces questions, discute de la géologie du manteau, des principales roches-mères des diamants et de l’impact des processus dans le manteau, compare les propriétés et les caractéristiques des micro- et des macrodiamants et définit les étapes pour identifier et mitiger le risque de résorption des diamants et son impact sur la relation entre la taille et la qualité des diamants.
Mots-Clé Barbure, diamant, distribution, distribution de Pearson de type V, éclogite, évaluation des ressources, kimberlite, log-Laplace, log-normal, manteau, morphologie, paragenèse, péridotite, populations, résorption
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