Economic Geology of Renard 3, Québec, Canada: A Diamondiferous, Multi-Phase Pipe Infilled with Hypabyssal and Tuffisitic Kimberlite

Renard 3 is one of a ~640 Ma. cluster of nine diamondiferous kimberlite pipes in the Otish Mountains region of Québec, Canada. The external and internal geology of Renard 3 were investigated to assess the resource volumes and diamond contents, information that was used to develop an Indicated Mineral Resource of 106 carats per hundred tonnes. The internal geology was determined by differentiating distinct kimberlite units using a combination of megascopic, macroscopic, and microscopic features. The units were assessed and modelled as five distinct, vertically extensive pipe-forming phases of kimberlite, each separated by steep and predominantly sharp internal contacts. Each phase is dominated by one of the following textural varieties of kimberlite: (i) volcaniclastic kimberlite that is classified as tuffisitic kimberlite breccia, (ii) coherent kimberlite that is classified as hypabyssal kimberlite, or (iii) transitional kimberlite that is intermediate between tuffisitic and hypabyssal. The combination of observed kimberlite textures, rock types, associated country rock features, emplacement age and regional geological setting indicates that Renard 3 is an eroded, deep diatreme to root zone kimberlite pipe comparable to others in the Renard cluster, Gahcho Kué, Northwest Territories, Canada and Kimberley, South Africa. The worldwide geological correlations significantly increase the degree of confidence in the Renard 3 geological model and, in turn, the Mineral Resource Estimate, highlighting the importance kimberlite geology has in the economic assessment of a kimberlite.