Geochemistry of metamorphic rocks of Dizi Series of the Southern Slope zone of the Greater Caucasus

The Dizi Series is exposed within the Southern Slope zone of the Greater Caucasus, in the core of the Svaneti anticlinorium. It is mainly composed of metaterrigenous phyllite-like and volcanogenic rocks, which are faunistically dated from the Devonian to the Triassic inclusive. During Variscan orogeny these rocks (sandstones, gravelstones, argillites, greywackes, carbonaceous-clayey shales, silicites, tuff sandstones, volcanics and limestones) underwent regional metamorphism of low-temperature subfacies of green schist facies. Later, due to the contact impact of the Middle Jurassic intrusions, they were transformed into graphitized phyllites, phyllitic schists, marbles, and various hornfelses. The aim of the presented study was the geochemical research of metamorphic rocks (except of silicites and limestones) of the Dizi Series. For this purpose the geochemical study of 20 key rock samples were performed including determination of major components, RE and REE; an XRD investigation of material was carried out; a number of diagrams were used for determination of primary rocks of the metamorphites and for restoration of conditions of their formation. The lithochemical types, lithological features and composition of the original rocks of the Dizi Series metamorphic rocks were studied. (authors)