(Fe-Ca-Al)-phosphate mineralization enriched with rare earth elements in the sediments of the middle Jurassic paleovalley (Shankinka Occurrence, Moscow Region, central part of the Russian Plate)

Abstract

A new occurrence of phosphate mineralization – named Shankinka – has been explored in the mouth of the Fed’kovskaya river in the Ruza District of the Moscow region, of which, the most common mineral phases include delvauxite, mitridatite, fluorapatite and crandallite. It has been established that all the Fe-Ca-Al phosphates occurrences in the region are associated with the Bajocian-Bathonian paleovalleys embedded in the Carboniferous rocks and partially filled with Callovian sediments. The structural features of the phosphatization zone as well as its enrichment with Co, Ni, Zn, Cu, and REE indicate a possible link between the Oxfordian organic-rich sediment and phosphate mineralization. It can be assumed that epigenetic phosphate mineralization was a result of the seepage of phosphorus-rich pore waters released from the Oxfordian organic-rich sediment into the underlying Callovian permeable rocks rich in iron minerals.