Most of the deposits of the East Region are of the volcanogenic massive sulphide (VMS): Orlovsky, Artemyevsky, Irtyshsky underground mines.
Orlovsky is an active underground mine exploiting a large, polymetallic, high grade, and gold rich VMS deposit. It comprises the Main Orebody, which comprises an upper and lower part with an irregular pod-like shape, 20° to 30° dip to the SW, average thickness of 35m and down-dip extent of 600 m. It is now almost worked out, with the remaining resources consisting of remnant blocks distributed in the lower part of the orebody and representing some 25% of the whole deposit. A 0.85 Mt oxidised cap on the upper part of the orebody has been excluded from the resources since until now, no technology has been successfully developed to treat it.
350 m to the SW of the lower part of the Main Orebody is the New Orebody comprising a southern portion with a 10° to 15° dip to the SW and thickness of up to 56m and a northern portion with very high grade and thickness of 5-20 m. The combined New Orebody occupies a surface area in long section of some 250 m by 150 m and accounts for the rest of the resources in the deposit.
Artemyevsky is an operating underground mine exploiting a larg, high grade, polymetallic, gold and silver-rich VMS deposit. A number of different steeply dipping ore bodies have been identified in the deposit, the most important of which is the Main Orebody, with a strike length of 1,300 m and maximu ........