Sodic fenites of the Oktiabrski Complex exposed in the Khlibodarivka quarry (East Azov, SE Ukraine): reconstruction of their growth history
Dumańska-Słowik, Magdalena; Heflik, Wiesław; Kromska, Agnieszka; Sikorska, Magdalena
published: Mar 1, 2015
Sodic fenites of the Oktiabrski Complex exposed in the Khlibodarivka quarry result from alkali metasomatism of granitoid rocks. Compositionally at least three generations of minerals can be distinguished. Plagioclase (i.e. oligoclase-andesine), microcline, dark mica of the biotite series, ferrohastingsite and quartz with subordinate zircon, ilmenite and garnet most probably made up the original host rock. Fenitizing fluids with high activities of alkalis, mainly Na and subordinately K, and enriched in Fe, Al, Rb and Nb, originated from alkaline intrusion of the Oktiabrski Complex, systematically changed the host rock. As a result albite, perthites, nepheline, alkaline amphiboles (arfvedsonite-riebeckite) and pyrochlore were formed. The third generation of minerals is represented by calcite, fluorite, apatite, pseudorutile originating from primary ilmenite, and REE-bearing carbonates, i.e. parasite-(Ce) and bastnäsite-(Ce).