THE SPECTROSCOPIC CHARACTERISTIC OF ZIRCON FROM THE NEOGENE SAMOTKAN TITANIUM-ZIRCONIUM PLACER (MIDDLE-DNIPRO MEGABLOK OF UKRAINIAN SHIELD)

The infared (IR) spectra and photoluminescence (PhL) of the large collection of zircon grains from the Neogen Samotkan placer (Middle Dnieper block, Ukrainian shield) with different shapes, colors, and degrees of their rolling were investigated. The different PhL intensity and shades of yellow, the high degree of crystallinity and fixation of bands of various oxygen-hydrogen defects ОНn in their IR spectra indicate zircons polygenic origin. High degree of crystallinity of many very small, mostly rounded, shiny zircon grains and presence of weak, narrow stretching bands of OH groups at 3420 and 3385 cm^-1 on the background of the wide stretching band of structural water in their IR spectra allows us to assume their mantle origin and kimberlite genesis. The identified differences in the luminescence color of these zircons may indicate their crystallization under variable RT parameters in the H₂O – СО₂ system during the rise of kimberlite melts to the surface and already directly in the explosion tubes. Based on the character of the IR spectrum and the low degree of metamictization, it was determined that gabbro-norites and metaporphyries of the Middle Dnieper region, similar to the picrite porphyrites of the Yagodka tube (Sakha-Yakutia, russian federation), were probably the parent rocks for some other zircons.