Trends in Some Geochemical Parameters of Fine-Grained Clastic Rocks of Lower Riphean Sedimentary Sequences in the Northeastern and Central Parts of the Bashkirian Meganticlinorium, Southern Urals

The type sections of the Lower Riphean Burzyan Group (Ai, Satka, and Bakal formations) are located in the northeast part of the Bashkirian meganticlinorium. In its central and southern regions, the above formations are traditionally compared with the Bolshoi Inzer, Suran, and Yusha formations. Our studies whose results are discussed herein were centered on trends in the indicator ratios of trace elements in clay rocks of the six formations to obtain arguments in support of certain variants of their correlations. The trends in the average geochemical characteristics of clay rocks of the Burzyan Group in the northeastern and central + southern regions of the meganticlinorium, reflecting the composition of their parental rocks, were found out to be notably different. This does not necessarily indicate that individual correlations between the Burzyan Group rocks in various regions should be incorrect but rather highlights the necessity to revisit this problem.