Mineralogy and geochemistry of carbonatite-silicatexenoliths of volcanic rocks from Gheklar area west ofMarand (E. Azerbaijan province)

In the west of Marand in Ghekhlar area, the Upper MiocenePleistocene
volcanic rocks, including intermediate to acidic basic alkaline
and lampr~phyric, are extensive exposed. Trachy-andesite rocks of this area
contain carbonatite-silicate xenoliths, which according to mineralogical
studies, are calcite - carbonatite type. The minerals of calcite, diopside,
anorthite, phlogopite, amphibole, apatite, biotite and titano-magnetite are
essential minerals, which belong to calcic and hydrous carbonatite types.
The dacitic volcanic rocks of this area also contain carbonates globules that
formed fr9m calcite and euhedral apatites. These xenoliths are
geochemically characterized by high content ofCaO, Fe203, MgO, P20S, Cr,
Ni, Y, Cu, Zn which are related to host rock. REE pattern displays
fractionated pattern (CelYb)N = 24-29 and lack ofEu negative signature. The
source of these xenoliths can be attributed to disequilibrium partial melting
of metasomatized mantle by either released fluids from subducted slab or
silicate melts derived from melting of subducted slab. Association of
silicates and carbonates in xenoliths can be related to mingling and
immiscible fluids.