Nykanorova Y. Geological formation conditions and material features of fenite haloes (at the example of Chernigovka carbonatite massif of Ukrainian Shield and its analogues)

The thesis is devoted to the complex research of fenite halos of linear structural-morphological type carbonatite massifs. It has been found, that fenite halos of linear carbonatite massifs, in contrast to central type massifs, are usually characterized by marked morphological asymmetry. The fact of compositional convergence of host rocks contrast types during fenitization process and geochemical zonation of fenite halos has been confirmed on the rock and mineral levels. The possibility to determine metasomatic changes as such that belong to fenite type and identify host rocks types using data about admixture elements distribution in the most common accessory minerals has been confirmed. Multiplicative geochemical zonation index, general for studied linear carbonatite massifs, that allows to specify the position of fenite halo outer boundary and estimate host rocks transformation level, has been suggested for the first time.