First Age and Geochemical Data on Zircon from Riebeckite Granites of the Verkhnee Espe Rare Earth–Rare Metal Deposit, East Kazakhstan

Abstract This paper is dedicated to the isotope-geochemical study of zircon from riebeckite granites Verkhnee Espe rare earth-rare metal deposit and specification its U–Pb age. Zircon massif peculiar in high content non-formula elements (up 43000 ppm REE, up 22000 Y, others) demonstrates a clearly expressed heterogeneous structure. The central rim zones show “magmatic” rare-earth element (REE) distribution. intermediate are characterized by flattening REE patterns an anomalous enrichment Nb, Ca. compositional feature may be caused impact fluid-saturated granite melts enriched incompatible trace elements. δ 18 О values 5.83–7.16‰, which generally corresponds formed granitoid melts. age earth–rare 283 ± 3 Ma, indicates that there no significant gap between crystallization, on one hand, metasomatic processes ore generation, other.