Аннотации:
© 2006-2016 Asian Research Publishing Network (ARPN).The Middle-Upper Permian rocks, Volga river reference section, were geochemically examined by XRF analysis to reveal the Ural provenance, aridity and humidity levels, smectite-illite association as indicator of environmental change. Geochemical variations correlate with the regional lithostratigraphic scheme and cyclicity.