Evolution of Placer Formation in Shelf Regions of Russia

Paleogeographic comparative analysis of placer deposits at shelves of Russia shows that all placer provinces and megaprovinces of this region are characterized by complex polymineral profiles. They reflect combinations of various rocks and native sources in feeding areas and intricate transformations of placer mineral assemblages in the course of transport and multifold redeposition of material during alternating stages of continental and coastal-marine lithogenesis. It has been established that Cenozoic placers in shelf zones of Russia are asynchronous formations. The number and timing of major epochs of both proved and inferred placer formation markedly vary depending on the tectonic setting of shelf zones and evolution of the adjacent oceanic basins.