The composition of stable carbon and oxygen isotopes in the section of an isolated carbonate platform is analyzed. Traces of several global and subglobal transgressions and regressions have been found in the limestone strata. Some of these phenomena were associated with the Upper Kellwasser (at the Frasnian–Famennian boundary) and multiphase Hangenberg (at the Devonian–Carboniferous boundary) Events. Nevertheless, there were no considerable sea level fluctuations in the platform water area. There is no evidence for subaerial erosion. The bottom water during sedimentation was mostly in oxic conditions.
The paper is devoted to the specifics in the chemical composition of synorogenic clay rocks in var ious environments: the Ural foredeep, Olyutorskii terrane, Dnestr pericratonic trough, Indus-Gang trough, etc. The compositions of the rocks are plotted in conventionally utilized discriminant paleotectonic dia grams. It is demonstrated that the bulk composition of such rocks, which were formed under active tectonic conditions typical of the collisional evolutionary phase of mobile belts, reflects the nature of the rock assem blages produced during both the divergent and the convergent (including collisional) phases. Their mean composition is the closest to PAAS as an integrated parameter of the average composition of the continental crust. The materials presented in the publication suggest that data on the bulk composition of clay rocks shown in conventionally utilized discriminant diagrams, such as SiO 2 -K 2 O/Na 2 O, K 2 O/Na 2 O-SiO 2 /Al 2 O 3 , are insufficient to reproduce the tectonic environments in which these rocks were formed.
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