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Information × Registration Number 0217U001117, 0112U002429 , R & D reports Title Ore content of hypersolvus intrusions of syenites as promising object of rare metals of Ukrainian shield popup.stage_title Head Voznyak Dmytro Kostyantynovych, Registration Date 24-01-2017 Organization nstitute of Geochemistry, Mineralogy and Ore Formation popup.description2 The object of study is syenite massifs of the Ukrainian Shield: Yastrubetsky, Davidky, Velyka Vyska, Azov. The aim of this work is to draw a conclusion about the prospects of ore content Davidky, Velikа Vyska and Yastrebetsky syenite massifs comparing their mineralogical characteristics with those for the Azov syenite stock. Research methods are x-ray, electronography, XRF, optical microscopy, thermometry, cryometry, IR-spectrometry. Opening in Azov megablock of the Ukrainian Shield promising Azov deposit with non-traditional composition of the ore (britholite + zircon + fluorite) forced to pay attention to other megablocks for search signs of this type of mineralization. Atypical of the Azov Zr-REE deposits is caused by the special composition of magma and conditions of formation of Azov intrusions. It is timed to same stock alkali feldspar syenites called hypersolvus which are formed at high temperature, moderate pressure and are characterized by the specific composition of rock-forming minerals. The results of comparison showed that the syenites of Yastrubetsky, Davidky and Velyka Vyska massifs, as well as syenites of Azov stock, formed from the melt. These four massifs are gipersolvus type intrusions. The crystallization temperature of syenite rocks ranged from > 700 to 1000-1200 °C and decreased in a row: Velyka Vyska - Azov - Davidky - Yastrebetsky intrusions. In Yastrebetsky intrusion final crystallization of alkali feldspar occurred in subsolvus conditions. Gipersolvus feldspar of Velyka Vyska intrusions enriched in potassium and corresponds to the composition of sanidine, anorthoclase mineral composition is predominant in other intrusions. Crystallization of syenite melt was accompanied by melt heterogenisation - separation from silicate salt melts and separation of the latter on salic and femic parts. It was noted the crucial role of salt liquated in formation of phosphate (britholite, apatite) ores and indicator value of magmatic fluorite. The melts from which syenites crystallized is the product of magma differentiation for the Fenner trend, was accompanied by accumulation of iron in the residual melt. Azov and Yastrebetsky syenites the bodies of which are located in zones of deep faults formed from a higher level differentiation melts than Davidky and Velyka Vyska whose bodies are confined to the margins of anorthosite-rapakivigranite plutons. The predictive assessment ore-bearing of hypersolvus intrusions was given. The closest analogue of the Azov intrusion by the conditions of formation recognized Velyka Vyska intrusion. Product Description popup.authors Бельський Володимир Миколайович Возняк Дмитро Костянтинович Герасимець Ірина Миколаївна Гречановська Олена Євгенівна Кривдік Степан Григорович Кульчецька Ганна Олександрівна Курило Сергій Ігорович Черниш Дарина Сергіївна popup.nrat_date 2020-04-02 Close