| Aketasi gold deposit is located in southern margin of Altay polymetallic mineralization belt, and tectonically belonged to the joint of Siberia plate and Kazakhastan-Junggar plate, which is namely Almantai Neopaleozoic island arc zone. There are good conditions for gold mineralization in Altay polymetallic mineralization belt. It is known that the amount and distribution of gold deposit and gold occurrence are large with great resource potential. Owing to the exploration prospecting activity, Aketasi gold deposit has been developed into a small-scale gold deposit from a gold mineralization occurrence.By the geological field investigation and laboratory study, combined with previous work, the research has been done on characteristics of geology, geochemistry and genesis of Aketasi gold deposit, which would to the points as following:Firstly, the ore-bodis of Aketasi gold deposit are mainly hosted on the top of plagioclase granite, and the quartz veins which filling the fissuring in the contact zone of wall rock and plagioclase granite. The ore-bodies were controlled by fracture obviously, which reflect that the regional structures of north-western and approximately east-western trend has controlled secondary structures, ultimately controlled metallogenesis of this ore district.Secondly, Because of the activitis of regional structures of Irtysh dislocation and its secondary structures, the metallogenic process of Aketasi gold deposit was composed of two main stages and four substages:siliconization-pyritization, quartz veins; gold-pyritization-quartz stockwork; quartz stockwork-carbonate veins; limonitization.Thirdly, wall-rock alteration is widely developed in the mining area in the form of propylitization and its main characteristics are that epidotization-Chloritization-carbonatization. Silicification, pyritization and sericitization were closely related to the gold mineralization. The tuff in the contact of the Beitashan Group of Middle Devonian and rocks had been altered into low-grade metamorpgic crystal tuff, crystal crumbs lithic tuff, phyllitic altered crystal tuff, and sericite.Fourthly, the main ore minerals are pyrite, chalcopyrite, magnetite, native gold, silver, speculum iron, chessylite, bornite, malachite, limonite. The main gangue minerals are quartz, calcite, sericite, chlorite, epodote.Fifthly, the study of fluid inclusion indicated that the temperature of mineralization was between220℃and321℃,which was an moderate temperature environment. The study of hydrogen and oxygen isotope revealed that the fluid of mineralization was mixed by magmatic water and atmospheric water. The study of sulfur isotope showed that the sulfur derived from mantle and the sulfur of stratum also came from mantle.Finally, based on the analysis of the characteristics of ore deposit geology and geochemical of Aketasi gold deposit, it can be safely got the conclusion that the type of Aketasi gold deposit is a kind of mesothermal quartz vein type gold deposit. |
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