Zirconology of phenites of the Ilmeny Mountains (Southern Urals)

Phenites are rocks developed in the exocontact zone between miaskites and metamorphic rocks (gneisses, migmatites, and amphibolites) with gradual transitions between them. Phenites have a fine grained granoblastic texture and distinct schistosity. They consist of feldspar (70%), amphibole (up to 9%), pyroxene (10%), quartz, biotite, sphene, apatite, zir con, and rare grains of nepheline. According to the relations of these minerals, the next varieties of phen ites are distinguished: amphibole, pyroxeneamphib ole, and pyroxene. They often alternate with mias kites, syenites, phenitized gneisses, and amphibolites. At the contact with phenites, miaskites and syenites are milonitized and cataclazed