Scientific publications

The features of the distribution of trace and rare-earth elements were studied in amphibolites of the Kharbey metamorphic complex of the Polar Urals, one of the largest protrusions of the Lower Precambrian basement within the Urals folded region. Among the pargasitehastingsite amphibolites in the central parts of the complex, there occur moderate and high-titanium rocks with elevated contents of LILE and LREE ((La/Yb)n – 1.33–3.80), similar in composition to basalts of continental rifts and island arcs, as well as low-titanium metavolcanites with low contents of LILE and LREE ((La/Yb)n – 0.61–1.32), which are geochemically similar to tholeiites of arcs and back-arc basins. The barroisitic amphibolites of the western part of the Kharbey metamorphic complex, which were studied for the first time, differ in the content of rare and rare-earth elements from the pargasite-hastingsite varieties. They contain moderate concentrations of titanium, lower amounts of LILE and LREE ((La/Yb)n – 0.37–0.53), and are similar in composition to N-MORB basalts formed from a depleted source. The differences in the geochemical compositionof metabasalts are most likely associated with the evolution of magmatic melt as a result of changes in the depth of magma generation, the degree of partial melting of the mother source, and the influence of aqueous fluid.