The article summarizes previous studies of the so-called "pyrope-bearing tuffs" of the Sivikagna volcanotectonic structure (Afanasiev et al., 1999, 2010), which suggested the existence of kimberlites within this structure, and recent studies of a kimberlite sample and a metamorphic rock sample from this area, which definitively confirmed this assumption. The article substantiates the existence of a field of Mesozoic kimberlites that penetrated the Lower Triassic tuffs of the trap formation in the Sivikagna River basin in the territory of the Tunguska syneclise. A prerequisite for the search for kimberlites in this area was the discovery of kimberlite indicator minerals in the tuff sequence. There are two groups of indicator minerals: (1) completely "fresh" minerals, corresponding to their state in the kimberlite; (2) minerals with signs of erosion and hypergenic corrosion, corresponding to the state of indicator minerals in intermediate reservoirs. The first group of minerals is present in kimberlites that broke through tuffs of the trap formation. The second group of minerals was captured from the Upper Palaeozoic intermediate reservoir located under these rocks. A kimberlite sample found on the tuff surface and a metamorphic rock sample (metapelite) were studied in detail. The following formations were established in the territory of the Sivikagna volcanotectonic structure: (a) Mesozoic kimberlite bodies, which broke through tuffs; (b) an Upper Palaeozoic intermediate reservoir of indicator minerals of Middle Palaeozoic kimberlites beneath the rocks of the trap formation; (c) the crustal section beneath the Sivikagna volcanotectonic structure contains metamorphic strata of the crystalline basement of the North Asian craton, which includes the West Aldan granite-greenstone terrane and the Tunguska tonalite-trondhjemite-gneiss terrane with the Archean consolidation.
