PALEOGENIC BASALT-TRACHYTIC FORMATION OF WEST CAUCASUS: GEOCHEMICAL SPECIALIZATION, QUESTION OF PETROGENESIS, GEODYNAMIC TYPISATION, METALLOGENY

Abstract

In the south-western parts of Geater Caucasus in the middle cource of river Mzimta the Paleogenic subalkaline rocks of basic and medial composition are occur. Petrographical and geochemical investigation have been carrying out and results of its analysis by RFA, ICP-MS methods was done. Enrichment of rocks by LILe, REE, HFSE, concentration of which are comparison with OIB have been identify. Rare-metal and rare-earth geochemical specialization of BTF rock is identified and its mercury and titanium metallogenic specialization. It is shown, that primary melts are appears in 2-3% melting of spinel peridotite. It is suggested that the reason of initiation of the partial melting in the upper mantle was a tectonic processes, which are touched on area of south-western margin of Scythian plate, synchronous with processes of rifting which are developing in Eocene in Black Sea area and in Adjaro-Trialeti depression.