distribution of trace elements controlled by sector and growth zonings in zircon from a miaskite pegmatite of the vishnegorsky massif, the southern urals

Data on the content and distribution of trace and rare-earth elements (sims method) in sectors and growth zones of a large zircon crystal from miaskite pegmatites of the vishnegogorsky massif are presented. the morphology of the zircon crystal is a combination of a dipyramid {111} and prism {010}. it has been established that the growth sector of dipyramid {111} is characterized by almost one order of magnitude higher contents of y, nb, ree, th; higher th/u and eu/eu* values; ree distribution spectra are flatter compared to prism {010} growth sector. a regular decrease in the content of trace and rare-earth elements in the direction from the central zone to the marginal zone of crystal growth was revealed. a smooth regression of zircon crystallization temperature of zircon from 960 °c in the central zone to 740 °c in the marginal zone of the dipyramid sector and 700-650 °c in the prism sector has been revealed, which may be a reflection of thermal evolution of the crystallization process. it is assumed that crystallization of the central zone of zircon occurred at early stages from a relatively trace-еlement-rich melt. the crystallization was completed at lower temperatures, probably, simultaneously with the formation of ree-concentrating minerals, which resulted in natural decrease of  content of trace and rare-earth elements in the melt and, consequently, in zircon crystallizing from it.