The age of back-arc spreading of the Ural paleoisland arc (by the results of Sm-Nd and U-Pb dating of dolerites and studying the composition of inclusions in zircon)

The data on the Silurian Sm–Nd age (426 ± 34 Ma) behind the arc-spreading dolerites of the sheeted dikes of Mount Azov in the Middle Urals was obtained. This age coincides with the age of zircons (428,5 ± 3,7 Ma) from the dolerites of the East-Ural megazone, which indicates the regional nature of the back-arc spreading processes. A study of the crystal ontogeny and composition of inclusions of metamorphogenic minerals in Mid-Upper Devonian zircons from the dikes of the city of Azov showed that the formation of zircons took place in the course of regional metamorphism of dolerites and enclosing basalts. This metamorphism coincides with the time of the onset of the collision in the late Devonian, and conflict processes manifested themselves over practically the entire width of the region.