On the «pugi» origin

Abstract

«Pugi» is local term used for hills and ridges built of sand and gravel; they are frequent at interfluves within the limits of Volga-Vyatka and Vetluga drainage basins where Upper Permian and Lower Trias rocks are exposed at the surface. Morphology of the «pugi», their distribution and lithology give evidences of fluvial accumulation of the sediments they are built of, the material source were rocks exposed at the western slope of the Northern and Middle Ural. Basal horizons of the deposits forming the pug ridges at present (due to selective erosion at the Volga-Vyatka interfluve) were accumulated by large rivers at Early Trias.