Mineralogical and petrographic characteristics of the diamondbearing formations of the Bulkur anticline, Republic of Sakha (Yakutia)

The article shows the results of mineralogical and petrographic studies of diamond-bearing Late Triassic tuffs, tuff gritstones, and tuff sandstones of the Bulkur member, differing in the amount of volcanogenic material into tuffs, orthoand paratuffites. The tuffs were formed as a result of phreatomagmatic eruptions during the Carnian in the Primorsky deep faults zone. Tuffs and orthotuffites contain outstanding pyrope concentrations with a small amount of diamond-bearing dunite-harzburgite parageneses and a high content of diamondbearing eclogites. For the first time, information about the MIC kelyphitic rims and widespread hypergene mineralization in the rocks is given. The presence of a considerable number of garnet megacrystals suggests the possible discovery of large diamond crystals, which will have a positive effect on the raw materials cost.