Evidence for the Suprasubduction Origin of Mantle Section Rocks of Voykar Ophiolite, Polar Urals

We studied mantle rocks in the northern part of the Voykar Ophiolite where the thickness of peridotite sections reaches 6 km. Harzburgite depleted to a variable degree in basaltic material predominates among the rocks. Dunite makes up about 20% of peridotites and represents pathways, along which mantle melts migrated during the ascent of host harzburgite under the influence of stress. Pyroxenite veins associate with dunite in space. Dunite and pyroxenite were formed within the harzburgite section on the final stage of magmatic evolution of mantle section. Pyroxenites were studied in detail and sampled in the area between two rivers Khoila-Left Paiera and Lagorta. Melts participated in pyroxenite formation have concentrations of incompatible elements indicating their formation during progressive melting of the mantle wedge above the subduction zone. Consequently, the mantle section of the Voykar ophiolite may represent the upper parts of the mantle above the subduction zone.