Material composition and conditions of formation of upper proterozoic and upper Cambrian-lower Ordovician sandstones of the Northwestern Pay-Khoy

We present the results of our study of the Upper Proterozoic and Upper Cambrian-Lower Ordovician sandstones in the Northwestern Pay-Khoy Ridge to find diagnostic lithochemical criteria for the paleontological silent strata genesis. We established that oceanic island arc had been the area of formation of tuffaceous Late Riphean-Vendian sandstones of morozovskaya and sokolninskaya formations and island arc volcaniclastics - the main source of detritus. We revealed the affiliation of the Upper Cambrian-Lower Ordovician sandstones of hengurskaya formation to sedimentary coastal-marine formations formed under the conditions of active and passive continental margins. We found that a significant role in the formation of their structure, alongside with basic and intermediate volcanics compositions, was played by metasedimentary rocks, and especially the material composition of the hengurskaya sandstones supports their value as a target for ancient metamorphosed placer.