Yakutniproalmaz Institute, Yakutsk, Russia:

V. F. Kolganov, Head of a Laboratory, Candidate of Geological–Mineralogical Sciences
I. V. Zyryanov, Deputy Head for Science, Doctor of Engineering Sciences, ZyryanovIV@alrosa.ru

The article presents studies on feasibility of indirect appraisal of kimberlite deposit productivity based on the data on nonrecoverable microdiamonds (under 0.5 mm in size), which will enable a more than an order-of-magnitude decrease in amount of work connected with core sampling and will shorten the period of diamond-containing ore study at the stage of exploration and appraisal. In terms of ALROSA kimberlite pipes, it is shown that distribution of microdiamonds is identical with general diamond distribution in appraised reserves. Block models of lithological varieties of diamond-containing rocks and distributions of microdiamond in kimberlite pipes are described. The conversion factor determination procedure meant for overall evaluation of diamond ore (kimberlite) quality based on microdiamonds is set forth. The diamond contents determined based on radiation detection and based on microdiamonds are compared. The calculation and modeling prove feasibility of indirect appraisal of overall diamond content for a deposit or a separate geological block based on microdiamonds. At the same time, to make the method legal and to introduce it in practice of geological examination of kimberlite deposits, it isrequired to continue the research with a view to improving reliability and accuracy of approximation of data based on microdiamonds.

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