S. A. Grakhanov (PJSC «ALMAR-Arctic Diamonds», Karpinsky Institute), M. N. Goloburdina (Karpinsky Institute), A. S. Ivanov (St. Petersburg Mining University), I. V. Aschepkov (IGM SB RAS, GI SB RAS)

MINERALOGICAL AND PETROGRAPHIC CHARACTERISTICS OF THE DIAMOND-BEARING 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, ortho-and 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 diamond-bearing 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.
Keywords: diamond, deposit, placer, Triassic, north of the East Siberian Platform.