Sm-Nd age of picrites of the Lysogorsk complex (Southern Urals): evidence of initial middle riphean magmatism

The article presents new data on the age of the picrites of the Lysogorsk complex, common in the Taratash metamorphic complex (Bashkir meganticlinorium, western slope of the Southern Urals). Based on Sm-Nd dating (1409 ± 89 Ma) and calculated data on the crystallization pressure and temperature of mineral parageneses, it is concluded that picrites belong to the initial type of magmatism, which characterizes the initial stages of the Mashak magmatic event.

Tectonic situation in the area of Catav-Ivanovsk earthquakes in September 2018 (South Urals)

The structural features of the Katavsko-Yuryuzan faults zone are considered. According to the analysis of mesostructures, paleopole stresses, where horizontal northwest compression prevailed, were determined. Data on earthquakes, that occurred in September 2018 near the town of Katav-Ivanovsk, has been analyzed. Contradictions in determining the coordinates of epicenters and mechanisms of earthquakes foci calculated by different geological services were revealed. It is shown, that the situation of right-sided transpression, in which the structure of the northwestern part of the Bashkir meganticlinorium was formed, continues up to the present moment.

Geochemical specialization terrigenous deposits Bashkirian meganticlinorium

The paper presents materials on geology and geochemical specialization Riphean clastic rocks of Bashkirian meganticlinorium, including carbonaceous shales and conglomerates. In the last set high content of gold and platinum group elements, confined mainly to heavily dislocated zones. The conclusion is that the potentially ore-bearing zones in clastic sediments of the Bashkir meganticlinorium is a result of polygenic multistep processes, caused geodynamic development of the region in the Riphean-Vendian time.