Geological structure and genesis of quartz veins in the Ufalei complex exemplified by the Vein 2136

The data on the geological structure and petrography of host rocks of the Vein 2136 quartz deposit located in the eastern part of the Ufalei gneiss–amphibolite complex (the Southern Urals) are discussed. It is established that the deposit resulted from the metasomatic replacement of amphibolite by quartz. The following metasomatic succession was formed during metasomatosis: quartz → quartz–feldspar pegmatoid → biotite schist → amphibolite. The investigation of homogenized vapor–liquid inclusions in quartz and feldspars revealed that the deposit was formed at temperatures of 350–400°C.