LATE CENOZOIC PALEOCHANNEL MINERAL DEPOSITS OF THE TRANS-URALS PENEPLAIN

Late Cenozoic landscapes of the south flank of the Trans-Urals peneplain shaped in response to inherited planation and low erosion in terms of gradual replacement of warm humide conditions by semi-arid conditions in Miocene and by alteration of cold semi-humide and semi-arid conditions during the Pliocene-Quaternary. The area of peneplain is characterized by branched paleodrainage, among which the Miocene and Pliocene-Early Quaternary paleo-ravines and paleo-valleys are the most saved. Paleochannel deposits of different origin are connected to them – from distal placer deposits of precious stones (corundum), crystal and piezo-quartz, gold to infiltration deposits on the complex epigenetic geochemical barrier (reduction, hydrolysis, sorption, etc.) – uranium and satellite metals. This epigenetic mineralization is afacial and can be spatially coincided with different-type placer mineralization within paleochannels of the 1st-3rd orders. Sanarka River basin with its Neogene-Quaternary paleochannels is one of area where the coincidence of placer and epigenetic mineralization can be well observed. Within boundaries of the Trans-Urals peneplain more ancient (Mesozoic) gold and uranium paleochannel are also known.