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Ginayat Bekzhanov, Academy of mineral resourses of the Republic of Kazakhstan (Kazakhstan)
Yevgeny Ìàlchenko, «Geoincenter» LTD (Kazakhstan)
Valery Zhukovsky, JC «Centrkaznedra» (Kazakhstan)
Berikbol Khamzin, JC «Centrkaznedra» (Kazakhstan)
Tatjana Ìàlchenko, State Technical University (Kazakhstan)
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Two marginal-continental volcanic-plutonic belts - Devonian and Carboniferous-Permian generated on periphery of the Zhongaro-Balkhash paleoocean are allocated in Kazakhstan. Development of magmatism of volcanic belts is characterized by consecutive change of differentiated by basalt-andesite-rhyolit formations of the early stage by predominating rhyodacite-rhyolite ones of median stage and contrast basalt-rhyolite, basaltoid or silicic associations of raised alkalinity of a late stage of development. Within a Devonian belt two zones are allocated: one with lowered alkalinity and grade of potassium in rocks considered for Caledonian continent as frontal and another with raised alkalinity and grade of potassium in rocks (treated as rear). In frontal part of a Devonian belt, deposits of pyrite-polymetallic and «manto» types are known; in a rear zone on its border from a frontal one, most significant gold-copper deposits of porphyric type are localized; in external parts of a rear zone in terrigenous sediments, small deposits of cuprous sandstones type are concentrated. Within a Carboniferous-Permian belt, the frontal zone is characterized by more basic composition of volcanites, and main copper-porphyric deposits are connected with it. The rear zone of hercinic belt more often coincides with a Devonian volcanic belt where sedimentary basins with exclusively widely spreaded stratiform copper mineralization (deposits of the Zhezkazgan group) were formed.
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