Physicochemical and geodynamic conditions for the formation of the Sarsanginsky complex of the border zone of the Southern and Middle Urals

Abstract

The article describes the geological structure of the Sarsanginsky gabbro-diorite-plagiogranite complex located in the border zone of the Middle and South Urals. The formation of its massifs took place in the late Silurian time in the abyssal zone at depths of about 6,5–7,0 km. The temperature range of crystallization of granodiorites was 900–990 С, and for gabbro 1180–1280 С. The system pressure at this moment corresponded to 190–200 MPa. The gabbro that make up the massifs under consideration were formed under stretching conditions on the oceanic crust. In terms of petrogeochemical features, they correspond to rocks at the base of island arcs and belong to the ophiolite formation.