Afanasyeva Nadezhda Iosifovna RussiaKazanKazan Federal University, 4/5, Kremlevskaya St., Kazan, 420008, Russian-afanasieva@rambler.ru Author's articles Paleogene quartz sandstones of the Sosnovka Formation of the Uljanovsk-Syzran Volga region (Eastern Russian Platform): Mineral composition and origin