PECULIARITIES OF THE COMPOSITION AND THERMODYNAMIC CONDITIONS OF FORMATION OF ENDERBITES OF THE HAIVORONSKYI COMPLEX (SOUTH-WESTERN PART OF THE UKRAINIAN SHIELD)

Анотація

Mineralogical and petrographic features of enderbites of the Haivoronskyi complex in the south-western part of the Ukrainian Shield (the valley of the Pivdennyi Buh River from the town of Haivoron to the village of Zavallia) were studied. The complex of research included field geological observations on outcrops and in quarries and laboratory petrographic, mineralogical and petrogeochemical studies. Such minerals as quartz, plagioclase (albite–oligoclase, andesine– bytownite), K-feldspar (microcline), rhombic (ferrosilite) and monoclinic (diopside, augite) pyroxenes, garnets, biotite, apatite, ilmenite, monazite, carbonates (calcite, dolomite) have been described. The temperature of mineral formation was calculated using garnet-biotite, garnetorthopyroxene and two-feldspar geothermometers according to the data of various authors using theoretical calculations and a graphic method. The thermodynamic conditions for the formation of enderbites during three stages were determined on the basis of the conducted research and literature data.