Fig. 3

Schematic reconstruction of the Late Permian to Early Triassic succession of shallow-marine lagoonal depositional environments caused by Late Permian regression and following Early Triassic transgression with typical microfacies types. 1 During the Late Permian carbonates were deposited in isolated lagoonal area with normal to slightly increased salinity, fossil assemblage includes calcareous algae, small foraminiferans and gastropods; a Microfacies 1 (sample BR-B)—dolowackestones to dolopackstones with calcareous algae and gastropods; b Microfacies 2 (sample BR-2/4), recrystallized algae and gastropod fragments, with presence of organic matter. 2 During Permian–Triassic transition evaporation salinity in the lagoonal areas was increased. The regression resulted in establishment of the ‘Transitional breccia’ facies; c common input of variable lithoclasts (sample BR-3/1); d common desiccation of the carbonate mud (sample BR-4/15). 3 The second phase of the Permian–Triassic transition was characterized by ongoing dolomitization, desiccation and input of lithoclasts into the shallow-marine environments, causing formation of more ‘Transitional breccia’ deposits; e dolomite crystals (sample BR-4/18); f breccia with different lithoclasts, e.g. dolomudstone and dolomite clasts (sample BR-1/0). 4 Transgression and re-establishment of the lagoonal settings in the Early Triassic; g dolowackestone with rare foraminiferans (sample BR-6/1); h dolomudstone with peloids and pyrite (marked by white circles) (sample BR-1/2)