The Geochemical Characteristics of the Early Riphean Navysh Volcanic Complex (Southern Urals)

Abstract

The Navysh volcanic complex, which is an integral part of the Ai Formation (Lower Riphean), overlies Archean–Early Proterozoic formations of the Taratash metamorphic complex. It is represented mainly by trachybasalts, as well as by dacites and metasomatic bostonites. The Navysh complex is subdivided for the first time here into several volcanic series, which differ in their contents of TiO₂ and several incompatible elements. The metasomatic nature of the bostonites has been proven. Reasons are given for excluding dacites from the composition of the Navysh complex.