stripes
The 50 km2, east-west-trending, steeply inclined Yarkhich intrusion is composed of nepheline and peralkaline syenites, which grade, via quartz syenites, to hastingsite granites in the north. The nepheline syenites are traversed by numerous stocks and dykes of porphyritic granite and syenite aplite. Apophyses of the alkaline rocks and zones of hornfelses extend into the country rocks. The rock-forming minerals of the nepheline and alkaline syenites are microcline-perthite, oligoclase-albite, nepheline, sodalite, lepidomelane, aegirine and amphibole; accessories are orthite, apatite, zircon, titanite and magnetite.
GORETSKAYA, E.I., UGLOV, S.M. and LESKOV, S.A. 1957. Materials on geology and metallogeny of South Gizzar. Doklady Akademii Nauk Tadzhikskoi SSR, 9: 68-72.
SHINKAREV, N.F. 1966. Upper Palaeozoic magmatism of Turkestan-Alay. Leningrad University Publishers, Leningrad. 152 pp.