This year’s GeoCanada conference and related workshops saw some attention to diamonds and kimberlites. Specifically those located in the western Canadian sedimentary basin (WCSB), covering Alberta and Saskatchewan.


The two main kimberlite clusters in this region are the well-known Fort a la Corne (FalC), and the lesser known Buffalo Head Hills (BHH) occurrences. The former cluster is in Saskatchewan and has been the focus of a major JV between Shore Gold (operator) and Newmont, the background of which was discussed in previous KIM Report posts. On the technical aspect of things, Shore Gold has done a lot of work in characterizing the complex structure of their two most economic kimberlite pipes: Orion South and Star (both are ~100 Ma). These pipes are composed of multiple units each formed during a separate volcanic eruption millions of years ago on the margins of an ancient shallow inland sea that covered most of what is today called the Great Plains. There are at least five  main units: Pense, Viking, Early Joli Fou, Late Joli Fou, and Cantuar (see the 3D model of the Star kimberlite below: different colours represent different petrological units). These units each erupted at a different time over many thousand of years, and differ in petrology, diamond grade and diamond size distribution. To further complicate things, these eruptions occurred over a timespan during which the inland sea was alternately expanding and contracting. The effect of these sedimentary processes (e.g. erosion, transportation, deposition) on the erupted kimberlite material led to the concentration of diamonds in...



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