Abstract:
Abstract:Meso-and Neoproterozoic strata are very well developed in the southern Ural Trough. They have a huge thickness and show distinct features of tectonic evolution and deposition of several stages. The Neoarchean and Lower Riphean are important host strata of large stratabound iron and magnesite deposits. The Middle Riphean (Mesoproterozoic) has very thick deposits with several depositional cycles, when carbonate rocks of abyssal to ramp facies were developed. After the Neoproterozoic last glaciation, the White Sea fauna (Ediacaran fauna), which may be used for global correlation, appeared in the Vendian System. The authors for the first time recognize three sets of molar-tooth structures in the Meso- and Neoproterozoic strata of the Southern Ural area. Of these, the molar-tooth structure in carbonate rocks of the Bakal Formation alternates and is associated with seismic liquefied veins, and even the molar-tooth structures are also developed in large-scale stromatolites in the lower Riphean Staka and Bakal formations. This feature indicates that the molar-tooth structure in carbonate rocks is related to seismic liquefaction. The age of the three sets of molar-tooth structures is largely close to that of the molar-tooth structure (liquefied vein) found in the Meso- and Neoproterozoic strata in the North China block.