![]() ![]() The constituents grade in size from very fine to coarse macrocrystic kimberlite, through to a basal breccia. One of these phases is a primary pyroclastic airfall mega-graded bed up to 130 m in thickness. The central part of the infill is dominated by several contrasting phases of kimberlite. ![]() The infilling of the 140/141 crater is complex, resulting from multiple phases of kimberlite. The 140/141 kimberlite is the largest delineated body in the province, estimated to have an areal extent below glacial Quaternary sediments in excess of 200 ha. Each body is composed of contrasting types of kimberlite reflecting different volcanic histories and, therefore, are considered separately. The bodies range in size up to 2000 m in diameter but are mainly less than 200 m thick and thus comprise relatively thin, but high volume, pyroclastic kimberlite deposits. Many of the bodies were formed during a marine regression by a two-stage process, firstly the excavation of shallow, but wide, craters and then subsequent infilling by xenolith-poor, crater-facies, subaerial, primary pyroclastic kimberlite. ![]() The Cretaceous age Fort à la Corne (FALC) kimberlite province comprises at least 70 bodies, which were emplaced near the edge of the Western Canadian Interior Seaway during cycles of marine transgression and regression. ![]()
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