The Major Types of the Weathering Crust of the Eastern Russian Plate and its Mineralogical and Geochemical Features

The long continental period in the East of the Russian plate (the upper Proterozoic – the middle Devonian) caused the formation of a weathering crust on the crystalline basement rocks. In pre-Devonian time, due to the washing-out and the subsequent processes of redeposition of substance, two types of weathering crust were formed: displaced and non-displaced. The widespread weathering crust of the crystalline basement of the East of the Russian plate is a unique object for studying the mineral formation processes of ancient weathering. Complex mineralogical and geochemical studies of the weathering crust are of practical value for the creation of a full picture of the development of the deep horizons of the earth crust and a forecast of mineral deposits.