Summary:
Most of the deposits of the East Region are of the volcanogenic massive sulphide (VMS): Orlovsky, Artemyevsky, Irtyshsky underground mines.
Orlovsky
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
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 maximum thickness of 200 m. This is the sole source of ore at the present time, with working on the 7, 8, 9 and 10 Levels. The higher-grade but less continuous Talovskaya Orebody is located 50-150 m in the footwall of the main Orebody, while the Kamishinskaya orebody forms a protective pillar below an old open pit and to protect the underground workings from flooding.
There are further six orebodies that form series sub-parallel lenses gently pitching to the east of the Main and Talovskaya orebodies.
The ore shows a vertical gradation through the individual bodies of polymetallic ores at the top, barite/polymetallic ores, polymetallic ores, copper/zinc ores and copper ores at the base. There are copper rich mineralised zones below these orebodies within the footwall volcanics of the Tavolka formation.
Irtyshsky
Irtyshsky is an operating underground mine exploiting a polymetallic volcanogenic massive sulphide (VMS) deposit of average size and grade. The mineralisation is of lenses with extensive strike extents but more limited down-dip persistence. There are three principal ore bodies: Main, South East, No 2.
Irtyshsky Principal Orebodies:
Main:
- Orebody Strike length - 2,500 m;
- Down-dip length - 750 m;
- Thickness - 3.5 m.
South East:
- Orebody Strike length - 3,000 m;
- Down-dip length - 400 m;
- Thickness - 2.7 m.
No 2:
- Orebody Strike length - 1,600 m;
- Down-dip length - 300 m;
- Thickness - 1.35 m.
The orebodies pitch slightly to the NW with their long axes roughly parallel. The average strike of the Irtyshsky ore body is NW-SE and the dip of the ore body is steep to sub- vertical (70-80°). The ore body is gently folded with secondary thickening of the ore lenses in the fold axes. The copper and zinc grades increase with increasing depth from surface.