Abstract:
The anomalous position of Eu in chondrite-normalized REE patterns of minerals has attracted the attention of geochemists for several decades. The works by J.A. Philpotts (1966–1973) on behavior of Eu and other REEs in igneous rocks commonly serve as theoretical principles for interpretation of this phenomenon. Based on similar radii of Eu2+ and Sr2+ ions, Philpotts suggested that an excess of Eu relative to the neighboring REEs is caused by reducing conditions in the mineral-forming system. The aim of this work is to expand substantially the physicochemical basis that allows interpretation of complicated geochemical relationships of Eu with other REEs in natural systems, especially with participation of high-temperature fluids.