(Fe–Ca–Al)-Phosphate Mineralization Enriched with Rare Earth Elements in Sediments of the Middle Jurassic Paleovalley (Shankinka Ore Occurrence, Moscow Region, Central Part of the Russian Plate)

A new occurrence of phosphate mineralization (Shankinka) has been explored in the Fedkovskaya River mouth, Ruza district, Moscow region. The most common mineral phases are delvauxite, mitridatite, fluorapatite, and crandallite. The Fe–Ca–Al phosphate occurrences in the region are associated with the Bajocian–Bathonian paleovalleys embedded in Carboniferous rocks and partially filled with Callovian sediments. The structural features of the phosphatization zone along with its enrichment with Co, Ni, Zn, Cu, and REE indicate a possible link between the overlying Oxfordian sediments and phosphate mineralization. The epigenetic phosphate mineralization can be related to the seepage of phosphorus-rich interstitial waters released from the Oxfordian organic-rich sediments into the underlying Callovian friable rocks enriched with Fe minerals.