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Place your photo here GOLD-BEARING STRUCTURE OF GREATER ALTAI: GEOTECTONIC POSITION AND RESEARCH CRITERIA Boris DYACHKOV, Erjzan Sapargaliev, Tatiana Oitseva Department of Geology and mining, D. Serikbaev East Kazakhstan State technical university, Kazakhstan, Email [email protected] The territory of Greater Altai is a member of the Central Asian mobile belt. In this region are concentrated large and unique deposits of Cu, Pb, Zn, Au, and other minerals. Scientific research is a continuation of the fundamental works on the problem of the "Greater Altai" (geology and metallogeny) [2]. In this paper, new ideas on the development of geology and the formation of ore-bearing structures of the Altai are considered by theoretical positions of global mobilism. Particular meaning is attached to paleo metal reconstructions of gold bearing structures and deposits. The most important problem now is to open new deposits. 1. Geotectonic position. Greater Altai structures are located in the Central Asian mobile belt, on the northwest flank of the Altai-Alashan area (Fig. 1). Figure 6 - Geotectonic position of Zaysan suture zone In Zaisan suture are more than 450 gold deposits and occurrences, including Bakyrchik, Suzdal, Kuludzhun, Maralikha, Manka et al.), which formed a major East-Kazakhstan gold ore belt (Fig. 8). Belt takes a diagonal position relative to the Altai structures, in the north-west can be traced in Russia, in the south-east intersected rare metal granites of Qalba-Narym pluton (P1) and then continues in the South China. This regional position of gold belt opens up new capabilities for the prediction of new deposits on its flanks and deep levels. Figure 7 - Geological and geophysical section of the lithosphere at the Greater Altai according to Aleisk geotraverse [2]. Granite-metamorphic layer: 1 - Hercynides; 2 - Caledonian; 3 Proterozoic. Intrusive bodies: 4 - granites and granodiorites, plagiogranites; 5 - diorite and gabbro; 6 - metamorphic carbonaceous rocks. Meta basalt layer: 7 - amphibolites; 8 - granulites. The upper mantle: 9 - primary; 10 - ultrabasites; 11 - eclogite garnet; 12 diamondiferous eclogite; 13 - upwelling zones; 14 - gravity field curves (Δg); 15 - curves of the anomalous magnetic field (ΔT) 1 - ancient platforms and massifs; 2 - Baikal and 3 - Caledonian orogeny region; 4 – Altai-Alashan area; 5 - position of the Greater Altai Figure 1-The Greater Altai geotectonic position in the structures of the Central Asian belt The territory of Greater Altai covers the geological structure of the Rudny Altai, Qalba-Narym, West Qalba, Zharma-Saur and adjacent areas of Russia and China. Modern geological structures is a part of ancient paleocontinents (terranes) according to concept of mobilism, that drifted in the Paleo-Asian Ocean and closed in the stage of the Hercynian collision (C1-C3), forming a single geological structures of Greater Altai (Fig. 2). Figure 8 - Scheme of location of gold and rare metal zones in the structure of the Greater Altai 1 – border of Greater Altai and 2 - metallogenic zones (I - BeloubinskoSarymsaktinsk, II – Rudny-Altay, III - Irtysh, IV – Qalba-Narym, V - West Qalba, VI - Charsk, VII - Zharma-Saur, VIII - Sirektas - Sarsazansk); 3 - Irtysh zone crumple; 4 - East Kazakhstan gold ore belt; 5 - Kalba-Qarym rare metal belt; 6 - border areas of the ore district; 7 - 10 - rare metal deposits: 7 - albitegreisen (Sn, Ta), 8 -pegmatite (Ta, Nb, Be, Li et al.), 9 - greisen-quartz-veinlet (Sn, W), 10 quartz-vein (Sn, W); 11 - tin (Sn); 12 - gold deposits. Figure 2 - Greater Altai metallogeny division into areas. 1 – border of Greater Altai; 2 – of ore belts and 3 – of metallogenic zones; 4 – Rudnoaltaisk goldcopper-polymetal, 5 – Qalba-Narym rare metal, 6 – West-Qalba gold bearing and 7 – Zharma-Saur multimetal Leading geological and industrial types of deposits: w w Q Q 1 р у д н о е т е л о № тае 100 нос C1v2-3 ar w w w w w w 50 гор w w w w w вск w w виг ое т ело № 2 0 ий рудн над Т1? 150 т v т v т т v v т v т v т т т т т т т 200 м inside Greater Altai, bounded by deep faults: 1) Rudny Altai gold-copper-polymetallic (Fe, Cu, Pb, Zn, Au, Ag, Pt, etc.). 2) Qalba-Narym rare metal (Ta, Nb, Be, Li, Cs, Sn, W). 3) West Qalba gold ore (Au, Ag, As, Sb). 4) Zharma-Saur multi metal (Cr, Ni, Co, Cu, Au, Hg, Mo, W, TR) [2,4]. Ore belts combine metallogenic zones, ore areas and deposits. Their location is shown in Fig. 3. mineralization, nests, veins and stockworks with splashes of goldsulphide (pyrite, arsenopyrite, stibnite less). Geological genetic model of mineralization is hydrothermal-metasomatic. Ore-accommodation sediments is tectonically disturbed volcano-clastic-carbonate rocks of Arkalyk suite (C1v2-3). Determined election the association of gold mineralization to limestone and carbonaceous shales (Fig. 9). 2. Gold-sulphide-carbon (Bakyrchik) type characterized by 1 2 8 9 3 т w т т w 10 4 5 6 11 12 13 7 14 Figure 9 - The geological structure of the Suzdal deposit (plan and profile) 1 - sandstones, 2 - carbonaceous and argillaceous shale and 3 - limestone (Arkalyk suite C1v2-3), 4 - zone of gold-sulphide mineralization, 5 - ore bodies, 6- gold-bearing weathering crust (V. I. Begaev et.al., 1990) 2. Metallogenic zoning. There are four-ore belt 1. Gold-sulfide (Suzdal) type represented by zones of large gold deposits "black shale type" of world class (Bakyrchik, Bolshevik, Glubokiy Log et al.) (Fig. 10). Deposits controlled by Kyzyl deep faults recorded by system of dynamic metamorphism zones, breccia, shearing and hydrothermal alteration of host rocks elevated carbon level (Bukon suite C2-3) [1]. Mineralization model shown a dual source of ore material: 1) sediment, due to denudation of the gold-bearing weathering crust and the accumulation of gold in cretaceous-water carbonaceous sediments, and 2) juvenile, associated with granitoid magmatism and concentration gold in the dynamic metamorphism zone (Fig. 11). 3. Gold-listvenites (maralikha) type manifested in the South Altai. Maralikha deposit composed mainly by crystalline schists and amphibolite (PR?), enclosing a lenticular serpentinite body (on dunite and peridotites), linear body of gabbro and felsic dykes (Fig. 12). 4. Gold-sulphide stockwork (sekisovsky) type formed in collision geodynamic environment in the process of tectonic compression of Rudny Altai and Irtysh crumple zones. Figure 3 - Metallogenic map of the Greater Altai. Scale 1: 1 000 000. Figure 10 - Layout of deposits in Bakyrchik ore field 3. Types of deposits. The main types of gold and gold-bearing deposits of the 1 - ore-accommodation sediments of Bukon suite; 2 - zone of Kyzyl deep faultthrust; 3 - deposits of gold-sulphide-carbon type (deposits: 5 - Bolshevik, 6 – Chelobay, 7 – Bakyrchik, 8 - Glubokiy Log). GA formed in different geodynamic settings, genetically connected to certain oreforming formations differ in age, material composition and scale of mineralization. Location of deposits shown in Figure 4. Figure 4 - Layout of the ore zones and deposits 1 - boundary of the ore belt, 2 - border of metallogenic zones, 3 – Rudny Altai gold-copperpolymetallic belt, 4 - East Kazakhstan gold ore belt, 5 - Qalba-Narym rare metal, 6 - Zharma-Saur multi metal. Famous gold-copper-polymetallic deposits of volcanic type (Ridder-Sokolnoe, Tishinskoe, Zyryanovsk, etc.) formed in Rudny Altai in the rift geodynamic setting of Hercynian orogeny cycle and genetically associated with a group of basaltandesite-rhyolite formations (D1e-D3fr). Ore-controlling faults deep north-west direction contributed the duration of the volcanic processes and the cyclical nature of mineralization. Gold is associated component of firestone ores together with Ag, Pt, Cd, Se, Te, Bi and other elements. The average gold content in the ores of about 0.8-1 g/t. On the RidderSokolnoye deposit set high gold concentration (ore columns) as a system of secant quartz and barite-sulfide veinlets with Au content of more than 50 g/t (Fig. 5). The largest gold reserves are concentrated in the lower level of geochronology (D1e-D2ef1), which is considered as "a unique gold-silver-barite-polymetallic" [5]. Overall, Rudny Altai type of deposits compose a significant proportion of gold resources of Kazakhstan. Actually, gold deposits formed in the central part of the Greater Altai into stage of the Hercynian collision (C1-C3), in the horizontal displacement, engages and tuck of Kazakhstan and Siberian lithospheric plates. The area corresponds to the junction plates is Zaysan suture zone (Fig. 6). Zaysan suture zone this is a large collisional tectonic structure of the regional rank type (the length more than 1000 km, the width of 60-80 km), brings together the territory of West Qalba, Charsk zone, South Altai and continued in China. The deep composition is characterized by the elevation of the asthenosphere layer, the upper mantle (M surface) and meta basalt layer (surface K) (Fig. 7). Figure 11 - Mineralization model of Bakyrchik deposit. According to A. M. Mysnik [2]. Figure 12 - Geological scheme of Maralikha gold deposit, based on N. I. Borodaevsky and others. 1 - gabbro, 2 - ultrabasites, 3 – crystal schists, 4 amphibolite, 5 - faults, 6 - ore bodies. 1 - gold-bearing ground molasses, (C2-3); 2 - sea molasses (C2) and molassoids (C1); 3 - volcano-clastic formations; 4 – granitoids; 5 thermogradient zones. Conclusion 1. Based on paleo metallogenic reconstructions refined features of formation and geological conditions of accommodation major gold structures and deposits in different geodynamic settings and modes. 2. The main gold-copper-polymetallic deposits of Rudny Altai formed in the rift geodynamic setting (D1e-D3fr). Forecasting criteria defined communication deposits with Devonian volcanism, multistage of ore process, ore distribution at certain geochronological levels, and zoning of mineralization (1000-1500 m depth). 3. Actually gold deposits formed in collision geodynamic setting (C1-C3), in collision between Kazakhstan and Gorny Altai continental margins, the manifestations of the main phases of folding, formation of over thrust mélange structures and introduction gold bearing small intrusions and dykes (C2-3, and C3). 4. Ore-controlling meaning have a deep fault system of mantle-crust foundations, brecciated zone, collapse and gold-sulfide mineralization. Established favorable ore-hosting role among high carbonate (C1v2-3) and carbon content (C2-3). 5. The scientific and practical significance of research involves the separation of a large East Kazakhstan gold belt within which the projected new prospecting areas. References Figure 5 - Distribution of gold in lead and zinc ores of RidderSokolnoe deposit (on G. D. Ganzhenko) 1. Bakyrchik (Geology, geochemistry, mineralization) Ed. Narseev V.A. M.: CSRGI. 2001. - 174 p. 2. Greater Altai (geology and metallogeny). Bk. 1, 2 – Almaty: Gylym, 1998. 304 p.; RIO UAC RK, 2000. - 400 p. 3. Huge gold deposits of Central Asia. Strengthening the gold potential of Kazakhstan. - Almaty, 2014. - 10-22 pp. 4. Dyachkov B. A., Titov D. V., and Sapargaliev E. M. Ore Belts of the Greater Altai and Their Ore Resource Potential // Geology of Ore Deposits, 2009. Vol. 51. No 3. pp. 197-211. 5. Chekalin V. M., Dyachkov B. A., Rudny Altai base-metal: Localization of massive sulfide mineralization // Geology of Ore Deposits, November, 2013. Vol. 55, Issue 6, pp. 438-454.
