Rudnyi Altai

Rudnyi Altai 

(Ore Altai), the southwestern lower portion of the Altai, with large deposits of complex ores. The Rudnyi Altai is located in Eastern Kazakhstan Oblast of the Kazakh SSR and in Altai Krai of the RSFSR, chiefly between the Charysh and Irtysh rivers. It includes the Ubinka, Kolyvan’, and Kalbinskii ranges and spurs of the Tigirek, Ivanovskii, Ul’ba, and Kholzun ranges (elevations of 1,200–2,000 m). To the west, the mountains gradually lose height, assuming the character of low-mountain relief.

Technically, the Rudnyi Altai is a series of Hercynian geosynclinal depressions overlying the fragmented Alei-Terektin-skii Massif and bounded by two regional faults (crush zones) with a northwestern strike: the Irtysh and Northeastern crush zones. In the southeast, the structures of the Rudnyi Altai subside and give way to the structures of the Southern Altai; in the northwest, they are buried under Cenozoic deposits of the Western Siberian Lowland. The formation of the depressions, which are filled with terrigenous rock and vulcanites of acidic composition, began in the Lower Devonian and ended in the Lower Carboniferous with a general inversion, after which the bulk of intrusions occurred.

The deposits of complex ores found in the Rudnyi Altai are localized in strata of alternating terrigenous rhyodacite rocks and are closely associated with minor intrusions of Middle and Upper Paleozoic acidic and basic rocks. The ore bodies often have a sheetlike, pipelike, or irregular shape and are composed of massive and disseminated ores. The chief minerals of the ores include pyrite, sphalerite, galena, and chalcopyrite; of less significance are the gray ores, native silver and gold, and the tellurides. The main vein minerals include quartz, sericite, chlorite, barite, and the carbonates.

The most significant deposits of complex ores form two zones, which gravitate toward the crush zones with a northwestern strike. In the Irtysh Crush Zone there is a predominance of copper-lead-zinc ores (Orlovka, Zolotushka, Nikolaevka, Belousovka, Berezovskii, and other deposits), and in the Northeastern Crush Zone there is a predominance of lead-zinc ores (Rubtsovsk, Stepnoe, Talovka, Srednee, Zarechnyi, Korbolikha, Strizhanka, Gusliachikha, Leninogorsk, Tishinskii, Zyrianovsk, and other deposits). The Ust’-Kamenogorsk Lead-Zinc Combine, the Leninogorsk and Irtysh complex-ore combines, the Zyrianovsk Lead Combine, and other combines make use of these deposits.

REFERENCE

Nekhoroshev, V. P. Geologiia Altaia. Moscow, 1958.

D. I. GORZHEVSKII