The main Gahcho Kué kimberlite cluster comprises four kimberlite bodies: Hearne, 5034, Tuzo, and Tesla. Hearne, most of the 5034 Pipe, and the Tuzo and Tesla occur under Kennady Lake, which has an average depth of 8 m. The Tesla kimberlite body is not part of the current declared resources or reserves.
Gahcho Kué kimberlites are overlain by varying thickness of glacial boulder outwash and lake sediments (averaging 10 m thick), and have a combined water and sediment cover as much as 25 m thick.
Drill information suggests that Tuzo and 5034 are located on an inclined feeder dyke system, the GK dyke, which dips roughly 25 degrees NNE. A vertical feeder dyke, as it is common for most maar-diatreme volcanoes, was not identified. Hearne is located on another feeder dyke system which dips to the North. The feeder dyke systems were repeatedly active during emplacement, resulting in a complex facies architecture of the kimberlite bodies rising from the feeder dykes.
The kimberlite bodies are steep-sided comprising of several texturally distinct phases of kimberlite in which the textures vary from hypabyssal kimberlite (HK) to diatreme facies tuffisitic kimberlite (TK). TK displays many diagnostic features including abundant unaltered country rock xenoliths, pelletal lapilli, serpentinized olivine and a matrix composed of microlitic phlogopite and serpentine without carbonate. HK contains common fresh olivine set in a groundmass composed of monticell ........
