Lithochemical features of Vendian clay rocks of the Shkapovo-Shikhan depression: In search of camouflage pyroclastics

Research subject. Vendian clay rocks of the Shkapovo-Shikhan depression, which is situated in east Volga-Ural region, and volcanic tuffs present among deposits (Sylvitsa Asha groups) on western slope Middle South Urals. Material methods . The research was conducted using data content main rock-forming oxides about 70 samples tuffs. On this basis, a number indicator ratios (lithochemical modules) were calculated. These calculated values, as well contents some oxides, compared with both available literature threshold differentiate “ordinary sedimentary rocks” from those presumably comprising camouflage pyroclastics. Results. It impossible to draw any definite conclusion regarding presence pyroclastics Staropetrovo, Salikhovo Karlin formations depression based exclusively lithochemical studies. seems that investigated either contain no pyroclastics, or its amount rather small. Conclusions. In order reliably establish into bulk chemical composition should be continued more representative sample collection geochemical methods.