Grechanovskaya E. Mineralogy and formation of rock-forming zeolite deposits in Transcarpathians

Crystal-chemical and physical-chemical peculiarities of rock-forming zeolites (mordenite and clinoptilolite) and minor minerals of Transcarpathians deposits of Neogene volcanoclastic sediments of Teresvinskaya suite are described. The morphology and crystal peculiarities of rock-forming zeolites, their regions of coherent dispersion (RCD) and crystallinity are investigated. New X-ray methods for determination of composition and of Si/Al-ratio of rock forming-zeolites are represented. The crystal chemistry and physical-chemical features of mordenite and clinoptilolite are investigated on this basis. It is shown that different heat-resistance of their structure depends on composition and Si/Al-ratio - the basic technological zeolite feature which characterize the raw materials. Tuff-ignimbrites which located under zeolite tuffs of Sokyrnitsya deposite and adularia mineralization confined to them are established for the first time. The adularia morphological types are shown to have low structural efficiency, like high sanidine. It is shown by the results of study of primary inclusions in quartz and plagioclase that tuff-ignimbrite strata are formed at the temperature of 860 °C. The rock-forming zeolite deposits in Transcarpathians are formed at interaction between lipoclastic material and meteoritic water under the action of tuff-ignimbrite heat remaining strata by model of "geoautoclave" zeolitization. The porous clinoptilolite, adularia, analcime and secondary quartz are formed as a result of hydrothermal metasomatic process. Keywords: zeolite, mordenite, clinoptilolite, Si/Al-ratio, tuff-ignimbrites, adularia, sanidine, quartz, plagioclase, analcime, "geoautoclave" zeolitization.