Late devonian verkhneuralsk volcanic-plutonic association (East Magnitogorsk paleoisland arc, South Urals): age, petrology, geochemistry, ore potential and geodynamic setting)

The geology and petrogeochemical features of the Verkhneuralsk volcanic-plutonic association in the South Urals are characterized. The relevance of the work is determined by necessary analysis of magmatic evolution of the region to clarify ideas on geodynamic evolution of the South Urals. It is shown that this association includes comagmatic volcanic rocks of the Verkhneuralsk Sequence (trachybasalts, trachybasaltic andesites, trachyandesites, trachydacites and trachyriolites) and intrusive rocks of the Verkhneuralsk complex (subalkaline gabbroids, mozzonitoids, dioritoids and syenitoids). The structure of the Verkhneuralsk pluton is described and it is shown that it is composed of rocks of three intrusive phases. The leading mechanism of petrogenesis of the association is related to crystallization differentiation. New data on the age of the Verkhneuralsk pluton are presented and its ore (including economic Mo) potential is characterized. The igneous rocks of the Verkhneuralsk volcanic-plutonic association are typical representatives of the island-arc shoshonite series. Their localization in the western part of the East Magnitogorsk paleoisland arc is an additional argument in favor of the western fall (in modern coordinates) of the subduction paleozone at the time of their formation.